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Message boards : Sophie Germain Prime Search : Running SGS and 321 sieve nearly halves SGS CPU time

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321 LLR Gold: Earned 500,000 credits (561,549)Cullen LLR Amethyst: Earned 1,000,000 credits (1,169,946)ESP LLR Gold: Earned 500,000 credits (636,842)Generalized Cullen/Woodall LLR Gold: Earned 500,000 credits (615,145)PPS LLR Amethyst: Earned 1,000,000 credits (1,225,852)PSP LLR Gold: Earned 500,000 credits (663,928)SoB LLR Gold: Earned 500,000 credits (818,190)SR5 LLR Amethyst: Earned 1,000,000 credits (1,048,722)SGS LLR Amethyst: Earned 1,000,000 credits (1,046,813)TRP LLR Gold: Earned 500,000 credits (561,429)Woodall LLR Gold: Earned 500,000 credits (781,741)321 Sieve (suspended) Ruby: Earned 2,000,000 credits (2,107,153)PPS Sieve Amethyst: Earned 1,000,000 credits (1,045,010)AP 26/27 Ruby: Earned 2,000,000 credits (2,470,273)WW Emerald: Earned 50,000,000 credits (58,488,000)GFN Turquoise: Earned 5,000,000 credits (7,149,778)PSA Gold: Earned 500,000 credits (517,947)
Message 140068 - Posted: 3 May 2020 | 16:20:04 UTC
Last modified: 3 May 2020 | 16:30:50 UTC

So far I had run SGS and 321 sieve alongside. After reaching 321 sieve ruby, I deactivated it and focused solely on SGS.

Surprisingly, the CPU time for each SGS task went from approximately 970 s average to 1500 s average. I reactivated 321 sieve after 24 h and averages went down to the prior value. I think you can publicly view my tasks and see for yourselves, 321 sieve was off for May, 2nd. Recently I changed from 321 sieve to extended sierpinski and apparently SGS doesn't benefit from it. This is quite peculiar...

This increase happened for both machines (i7-4790K and i3-2120) though it was less pronounced for the i3, something like 1500 s vs 2000 s.

I guess this has to do with hyperthreading? Switching to fewer simultaneous tasks doesn't seem like a good solution, since that would probably leave CPU power unused. So should I keep running two subprojects?

Has anyone experienced this as well?


edit: I'm starting to believe this is more of a problem of scare ressources. Both machines have enough of ressource X to keep 2 or 4, respectively, SGS tasks running efficiently. 321 sieve doesn't need ressource X and if it runs alongside, no problem. But if I switch off 321 sieve the number of parallel SGS tasks increases, making the machine lack in ressource X (whatever that is) and CPU time per task increases.

Extended Sierpinki apparently requires ressource X as well, as running it parallel to SGS causes the increase as well.

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The "Shut up already!" badge:  This loud mouth has mansplained on the forums over 10 thousand times!  Sheesh!!!Discovered the World's First GFN-19 prime!!!Discovered 1 mega primeFound 1 prime in the 2018 Tour de PrimesFound 1 prime in the 2019 Tour de PrimesFound 1 prime in the 2020 Tour de PrimesFound 2 primes in the 2021 Tour de Primes321 LLR Ruby: Earned 2,000,000 credits (2,822,730)Cullen LLR Ruby: Earned 2,000,000 credits (3,624,591)ESP LLR Turquoise: Earned 5,000,000 credits (5,021,269)Generalized Cullen/Woodall LLR Ruby: Earned 2,000,000 credits (2,145,754)PPS LLR Jade: Earned 10,000,000 credits (19,532,715)PSP LLR Turquoise: Earned 5,000,000 credits (5,197,957)SoB LLR Sapphire: Earned 20,000,000 credits (34,291,181)SR5 LLR Jade: Earned 10,000,000 credits (10,007,110)SGS LLR Ruby: Earned 2,000,000 credits (3,710,224)TRP LLR Turquoise: Earned 5,000,000 credits (5,084,329)Woodall LLR Ruby: Earned 2,000,000 credits (2,963,361)321 Sieve (suspended) Jade: Earned 10,000,000 credits (10,061,196)Cullen/Woodall Sieve (suspended) Ruby: Earned 2,000,000 credits (4,170,256)Generalized Cullen/Woodall Sieve (suspended) Turquoise: Earned 5,000,000 credits (5,059,304)PPS Sieve Sapphire: Earned 20,000,000 credits (22,885,121)Sierpinski (ESP/PSP/SoB) Sieve (suspended) Amethyst: Earned 1,000,000 credits (1,035,522)TRP Sieve (suspended) Ruby: Earned 2,000,000 credits (2,051,121)AP 26/27 Jade: Earned 10,000,000 credits (10,118,303)WW Turquoise: Earned 5,000,000 credits (9,764,000)GFN Emerald: Earned 50,000,000 credits (77,882,617)PSA Jade: Earned 10,000,000 credits (12,445,029)
Message 140071 - Posted: 3 May 2020 | 16:46:40 UTC

LLR doesn't benefit from hyperthreading, while sieves do benefit from hyperthreading.

If you have hyperthreading enabled, this behavior makes sense.

If you want to run SGS, simply disable hyperthreading, or, equivalently, set BOINC to use only 50% of the "CPUs". Despite what you might think, you're *not* leaving processing power on the table when you do this. Hyperthreads aren't "full CPU cores", and LLR uses the part of the CPU that is NOT duplicated in the hyperthreads. There's only one full arithmetic unit per core (i.e., there's 1 arithmetic unit per 2 hyperthreads), so the best you can do with LLR is one task per physical core (i.e., 1 task for every 2 hyperthreads.)

If you leave hyperthreading enabled, you'll run twice as many SGS tasks simultaneously, but they'll take AT LEAST twice as long to run. They'll probably be slower, actually. The number of tasks you complete per day will either stay the same or go down -- but you will consume a lot more power and produce more heat.

The same or slightly less throughput, with more power consumption -- it's a lose-lose scenario.
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Message 140115 - Posted: 7 May 2020 | 9:10:44 UTC

That still doesn't really explain while SGS took about 60% of the CPU time when 321 sieve ran simultaneously, or does it? Or is the important part that no more than 2 SGS (on a 2 physical cores system) tasks run at the same time?

What I meant with wasted CPU time:

Scenario 1: 4 SGS tasks with 1500 s each = 9.6 SGS tasks per hour

Scenario 2: 2 SGS tasks with 970 s each plus 2 321 sieves with 3600 s each = 7.4 SGS tasks per hour plus 2 "321sieves" per hour

Scenario 3 (no HT): 2 SGS tasks with 675 s each (just a guess, assuming it's 50% of HT enabled) = 10.6 SGS tasks per hour (but no 321 sieves)



My experience was that switching HT off did not halve the CPU time of SGS tasks. I didn't run it long enough to be sure, but I will do some testing and report back.

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321 LLR Silver: Earned 100,000 credits (100,228)Cullen LLR Silver: Earned 100,000 credits (112,212)ESP LLR Bronze: Earned 10,000 credits (48,696)Generalized Cullen/Woodall LLR Bronze: Earned 10,000 credits (22,645)PPS LLR Amethyst: Earned 1,000,000 credits (1,363,778)PSP LLR Silver: Earned 100,000 credits (100,559)SoB LLR Silver: Earned 100,000 credits (138,888)SR5 LLR Bronze: Earned 10,000 credits (64,280)SGS LLR Silver: Earned 100,000 credits (100,702)TRP LLR Bronze: Earned 10,000 credits (67,784)Woodall LLR Silver: Earned 100,000 credits (117,864)321 Sieve (suspended) Gold: Earned 500,000 credits (506,814)Generalized Cullen/Woodall Sieve (suspended) Bronze: Earned 10,000 credits (30,033)PPS Sieve Amethyst: Earned 1,000,000 credits (1,007,929)AP 26/27 Silver: Earned 100,000 credits (161,720)WW Silver: Earned 100,000 credits (256,000)GFN Ruby: Earned 2,000,000 credits (2,167,035)PSA Silver: Earned 100,000 credits (373,034)
Message 140123 - Posted: 7 May 2020 | 12:18:07 UTC - in response to Message 140115.

That still doesn't really explain while SGS took about 60% of the CPU time when 321 sieve ran simultaneously, or does it? Or is the important part that no more than 2 SGS (on a 2 physical cores system) tasks run at the same time?

I think that is correct.
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321 LLR Gold: Earned 500,000 credits (561,549)Cullen LLR Amethyst: Earned 1,000,000 credits (1,169,946)ESP LLR Gold: Earned 500,000 credits (636,842)Generalized Cullen/Woodall LLR Gold: Earned 500,000 credits (615,145)PPS LLR Amethyst: Earned 1,000,000 credits (1,225,852)PSP LLR Gold: Earned 500,000 credits (663,928)SoB LLR Gold: Earned 500,000 credits (818,190)SR5 LLR Amethyst: Earned 1,000,000 credits (1,048,722)SGS LLR Amethyst: Earned 1,000,000 credits (1,046,813)TRP LLR Gold: Earned 500,000 credits (561,429)Woodall LLR Gold: Earned 500,000 credits (781,741)321 Sieve (suspended) Ruby: Earned 2,000,000 credits (2,107,153)PPS Sieve Amethyst: Earned 1,000,000 credits (1,045,010)AP 26/27 Ruby: Earned 2,000,000 credits (2,470,273)WW Emerald: Earned 50,000,000 credits (58,488,000)GFN Turquoise: Earned 5,000,000 credits (7,149,778)PSA Gold: Earned 500,000 credits (517,947)
Message 140125 - Posted: 7 May 2020 | 15:07:13 UTC

Admittedly, not much testing done so far, but after about 30 SGS tasks on the i3, I have an average of 1170 s per task while with HT it is about 1900 s. So overall throughput would be better with HT on, at least on that machine and if this keeps on.

Tomorrow morning I'll see what happened overnight.

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321 LLR Gold: Earned 500,000 credits (561,549)Cullen LLR Amethyst: Earned 1,000,000 credits (1,169,946)ESP LLR Gold: Earned 500,000 credits (636,842)Generalized Cullen/Woodall LLR Gold: Earned 500,000 credits (615,145)PPS LLR Amethyst: Earned 1,000,000 credits (1,225,852)PSP LLR Gold: Earned 500,000 credits (663,928)SoB LLR Gold: Earned 500,000 credits (818,190)SR5 LLR Amethyst: Earned 1,000,000 credits (1,048,722)SGS LLR Amethyst: Earned 1,000,000 credits (1,046,813)TRP LLR Gold: Earned 500,000 credits (561,429)Woodall LLR Gold: Earned 500,000 credits (781,741)321 Sieve (suspended) Ruby: Earned 2,000,000 credits (2,107,153)PPS Sieve Amethyst: Earned 1,000,000 credits (1,045,010)AP 26/27 Ruby: Earned 2,000,000 credits (2,470,273)WW Emerald: Earned 50,000,000 credits (58,488,000)GFN Turquoise: Earned 5,000,000 credits (7,149,778)PSA Gold: Earned 500,000 credits (517,947)
Message 140168 - Posted: 11 May 2020 | 5:05:57 UTC
Last modified: 11 May 2020 | 5:06:12 UTC

i3-2120 Win 10 x64:


50% processors usage (i.e. HT off) for 24 h (computer not used)

Throughput: 147 WUs
min CPU time: 1150 s


100% processors usage (i.e. HT on) for 24 h (computer not used)

Throughput: 162 WUs
max CPU time: 1963 s


Throughput has increased by 10%. I added min and max CPU times to show that even the slowest HT=on task took less than twice what the fastest HT=off task took.

From these results - and a short, couple of hours test I ran on an i7 some time ago - I would say, at least the current SGS tasks do benefit from hyperthreading.

Since it seems common knowledge here that SGS suffers from HT, are there statistics available?

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Discovered 2 mega primesFound 1 prime in the 2018 Tour de Primes321 LLR Turquoise: Earned 5,000,000 credits (5,477,467)Cullen LLR Gold: Earned 500,000 credits (776,297)ESP LLR Ruby: Earned 2,000,000 credits (3,120,351)Generalized Cullen/Woodall LLR Ruby: Earned 2,000,000 credits (2,056,207)PPS LLR Sapphire: Earned 20,000,000 credits (24,513,986)PSP LLR Turquoise: Earned 5,000,000 credits (5,027,818)SoB LLR Sapphire: Earned 20,000,000 credits (25,095,209)SR5 LLR Turquoise: Earned 5,000,000 credits (6,110,877)SGS LLR Ruby: Earned 2,000,000 credits (3,479,101)TRP LLR Turquoise: Earned 5,000,000 credits (7,070,795)Woodall LLR Amethyst: Earned 1,000,000 credits (1,693,614)321 Sieve (suspended) Emerald: Earned 50,000,000 credits (50,256,050)Cullen/Woodall Sieve (suspended) Turquoise: Earned 5,000,000 credits (5,571,178)Generalized Cullen/Woodall Sieve (suspended) Emerald: Earned 50,000,000 credits (50,009,610)PPS Sieve Double Silver: Earned 200,000,000 credits (321,368,164)Sierpinski (ESP/PSP/SoB) Sieve (suspended) Jade: Earned 10,000,000 credits (10,165,888)TRP Sieve (suspended) Sapphire: Earned 20,000,000 credits (20,071,454)AP 26/27 Turquoise: Earned 5,000,000 credits (6,616,128)WW Silver: Earned 100,000 credits (140,000)GFN Emerald: Earned 50,000,000 credits (53,658,746)PSA Double Bronze: Earned 100,000,000 credits (102,762,384)
Message 140175 - Posted: 11 May 2020 | 14:28:23 UTC - in response to Message 140168.

From these results - and a short, couple of hours test I ran on an i7 some time ago - I would say, at least the current SGS tasks do benefit from hyperthreading.

Since it seems common knowledge here that SGS suffers from HT, are there statistics available?

Your eyes do not deceive you. If you look far enough in old message threads there's a debate around the theme that *some* LLR tasks benefit from HT=on for *some* computers. So the official mantra is to try different things and see what works best for your particular CPU. The common knowledge effect that you also see is a sample bias, occuring because *some* people who did not see this throughput effect have a propensity to post that isn't so constrained by resource X.

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Found 1 prime in the 2019 Tour de PrimesFound 5 primes in the 2020 Tour de PrimesFound 4 primes in the 2021 Tour de Primes321 LLR Ruby: Earned 2,000,000 credits (2,216,329)Cullen LLR Ruby: Earned 2,000,000 credits (2,826,433)ESP LLR Ruby: Earned 2,000,000 credits (2,253,924)Generalized Cullen/Woodall LLR Ruby: Earned 2,000,000 credits (2,218,841)PPS LLR Sapphire: Earned 20,000,000 credits (20,008,683)PSP LLR Ruby: Earned 2,000,000 credits (2,327,946)SoB LLR Ruby: Earned 2,000,000 credits (2,230,141)SR5 LLR Ruby: Earned 2,000,000 credits (2,095,507)SGS LLR Ruby: Earned 2,000,000 credits (2,037,347)TRP LLR Ruby: Earned 2,000,000 credits (4,118,961)Woodall LLR Ruby: Earned 2,000,000 credits (2,247,622)321 Sieve (suspended) Ruby: Earned 2,000,000 credits (2,279,140)Generalized Cullen/Woodall Sieve (suspended) Turquoise: Earned 5,000,000 credits (6,057,633)PPS Sieve Double Bronze: Earned 100,000,000 credits (175,851,586)AP 26/27 Ruby: Earned 2,000,000 credits (2,919,046)WW Ruby: Earned 2,000,000 credits (2,372,000)GFN Sapphire: Earned 20,000,000 credits (30,694,989)
Message 140870 - Posted: 18 Jun 2020 | 2:14:03 UTC

I simply can't run all 8 threads on SGS with my old Dell PC's (4790) The temps hit 98 degrees and the fan screams!
Drop CPU to 50% and just use the 4 cores and temps are still in the high 80's/low 90's and no screaming fan. I'm comfortable with that.

I may try on a proper PC with better cooling..... or I might just stick to no H/T and not torture my system :)
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Message 140872 - Posted: 18 Jun 2020 | 2:58:59 UTC - in response to Message 140870.

I simply can't run all 8 threads on SGS with my old Dell PC's (4790) The temps hit 98 degrees and the fan screams!
Drop CPU to 50% and just use the 4 cores and temps are still in the high 80's/low 90's and no screaming fan. I'm comfortable with that.

I may try on a proper PC with better cooling..... or I might just stick to no H/T and not torture my system :)


HT isn't helping you, leave things at 50%. This is because LLR is using all the physical resources of a core, and HT is just forcing it to share back and forth with a second task. Increases power, decreases performance.

More importantly, if you are hitting that high a temperature, something else is wrong. Even on a prebuilt system, you shouldn't be that hot, even at 50%. I would recommend that if you haven't dusted the machine, certainly do that. Really, everyone should, at least once every couple months, and more often if you're like me and live down the road from an active gravel quarry.

Second, I think it's time that you replaced the thermal grease between the CPU and the heatsink. As it ages, it dries out and becomes much less effective at moving heat. To top it off, computer OEMs tend to cheap out in this area, and I bet yours is about 6 years old, now. Buy a tube of Noctua NH-T1, pull things off, clean off the old and crusted (isopropyl alcohol at a high percentage with cotton balls or a small rag are great for this, don't use water, and make sure everything has evaporated before moving on), apply the new paste (great videos online on the various methods) and reassemble. It will be a tremendous improvement and enhance the lifespan of the parts. Personally, I do a reapply every 2-3 years, including GPUs.
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Found 1 prime in the 2019 Tour de PrimesFound 5 primes in the 2020 Tour de PrimesFound 4 primes in the 2021 Tour de Primes321 LLR Ruby: Earned 2,000,000 credits (2,216,329)Cullen LLR Ruby: Earned 2,000,000 credits (2,826,433)ESP LLR Ruby: Earned 2,000,000 credits (2,253,924)Generalized Cullen/Woodall LLR Ruby: Earned 2,000,000 credits (2,218,841)PPS LLR Sapphire: Earned 20,000,000 credits (20,008,683)PSP LLR Ruby: Earned 2,000,000 credits (2,327,946)SoB LLR Ruby: Earned 2,000,000 credits (2,230,141)SR5 LLR Ruby: Earned 2,000,000 credits (2,095,507)SGS LLR Ruby: Earned 2,000,000 credits (2,037,347)TRP LLR Ruby: Earned 2,000,000 credits (4,118,961)Woodall LLR Ruby: Earned 2,000,000 credits (2,247,622)321 Sieve (suspended) Ruby: Earned 2,000,000 credits (2,279,140)Generalized Cullen/Woodall Sieve (suspended) Turquoise: Earned 5,000,000 credits (6,057,633)PPS Sieve Double Bronze: Earned 100,000,000 credits (175,851,586)AP 26/27 Ruby: Earned 2,000,000 credits (2,919,046)WW Ruby: Earned 2,000,000 credits (2,372,000)GFN Sapphire: Earned 20,000,000 credits (30,694,989)
Message 140877 - Posted: 18 Jun 2020 | 7:47:28 UTC - in response to Message 140872.
Last modified: 18 Jun 2020 | 7:52:01 UTC

Hi Grebuloner

I've actually done all that. I even used Noctua NT-H2.
I have a Dell 4770 (Optiplex 9020) and a Dell 4790 (T1700) both have similar temps. The 4770 I actually fitted a Noctua NH-L9i Low Profile heatsink which is much better than the crappy Intel one. It dropped temps a bit and is much quieter but we are still talking mid to high 80's.
These things only have a 80mm fan in the front...that's it. No provisions for more fans.

The other issue I have is they are in a room with 3 other PC's running. It's winter here in Australia and right now with my window open is a nice 25 degrees Celsius (77 F)

I don't see a way to get it any cooler.

I have another HP pc with a 3770S and same thing... its in a different room and is currently crunching a SoB on 4 cores and running at 91 degrees.
I realise this is too hot but hey....they were cheap crunching machines :)
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Discovered the World's First base 116 Generalized Cullen prime!!!Discovered 28 mega primesEliminated 7 conjecture "k"sDiscovered 1 Sophie Germain pairDiscovered 2 Fermat divisors2012 Tour de Primes highest prime count2012 Tour de Primes most Mountain Stage primes2015 Tour de Primes highest prime count2016 Tour de Primes highest prime countFound 23 primes in the 2018 Tour de PrimesFound 1 mega prime in the 2018 Tour de PrimesFound 2 primes in the 2018 Tour de Primes Mountain Stage2019 Tour de Primes highest prime countFound 22 primes in the 2019 Tour de Primes2020 Tour de Primes highest prime scoreFound 21 primes in the 2020 Tour de PrimesFound 4 mega primes in the 2020 Tour de PrimesFound 8 primes in the 2021 Tour de PrimesFound 1 mega prime in the 2021 Tour de Primes321 LLR Double Silver: Earned 200,000,000 credits (201,403,028)Cullen LLR Double Silver: Earned 200,000,000 credits (201,409,561)ESP LLR Double Silver: Earned 200,000,000 credits (203,249,784)Generalized Cullen/Woodall LLR Double Bronze: Earned 100,000,000 credits (109,580,172)PPS LLR Double Gold: Earned 500,000,000 credits (715,073,479)PSP LLR Double Bronze: Earned 100,000,000 credits (126,982,721)SoB LLR Double Bronze: Earned 100,000,000 credits (135,747,083)SR5 LLR Double Silver: Earned 200,000,000 credits (214,437,634)SGS LLR Double Silver: Earned 200,000,000 credits (201,595,744)TPS LLR (retired) Silver: Earned 100,000 credits (235,439)TRP LLR Double Silver: Earned 200,000,000 credits (201,215,056)Woodall LLR Double Bronze: Earned 100,000,000 credits (101,447,725)321 Sieve (suspended) Double Silver: Earned 200,000,000 credits (235,451,253)Cullen/Woodall Sieve (suspended) Emerald: Earned 50,000,000 credits (83,794,448)Generalized Cullen/Woodall Sieve (suspended) Double Silver: Earned 200,000,000 credits (285,139,652)PPS Sieve Double Ruby: Earned 2,000,000,000 credits (2,728,939,994)Sierpinski (ESP/PSP/SoB) Sieve (suspended) Double Silver: Earned 200,000,000 credits (203,523,358)TRP Sieve (suspended) Double Silver: Earned 200,000,000 credits (201,489,157)AP 26/27 Double Silver: Earned 200,000,000 credits (385,720,907)WW Double Silver: Earned 200,000,000 credits (412,280,000)GFN Double Ruby: Earned 2,000,000,000 credits (2,028,872,270)PSA Double Silver: Earned 200,000,000 credits (259,058,048)
Message 140880 - Posted: 18 Jun 2020 | 12:25:46 UTC - in response to Message 140877.

1
I have a Dell 4770 (Optiplex 9020) and a Dell 4790 (T1700) both have similar temps. The 4770 I actually fitted a Noctua NH-L9i Low Profile heatsink which is much better than the crappy Intel one. It dropped temps a bit and is much quieter but we are still talking mid to high 80's.
These things only have a 80mm fan in the front...that's it. No provisions for more fans.



What form factor (e.g., mini-tower, desktop, ultrasmall, etc.)? I have a number of the 9020 models, and none run that hot even with summer weather here in North America (even the all-in-ones with i7-4770s CPUs and the small form factor desktops with i7-4790 CPUs). One thing to check...make sure that you have the latest BIOS updates for those machines. Dell's early versions did have some fan control issues that were fixed with the updates.

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Discovered 1 mega primeFound 2 primes in the 2018 Tour de PrimesFound 4 primes in the 2019 Tour de PrimesFound 3 primes in the 2020 Tour de PrimesFound 1 mega prime in the 2020 Tour de PrimesFound 4 primes in the 2021 Tour de Primes321 LLR Sapphire: Earned 20,000,000 credits (20,176,149)Cullen LLR Jade: Earned 10,000,000 credits (10,858,937)ESP LLR Jade: Earned 10,000,000 credits (11,493,104)Generalized Cullen/Woodall LLR Jade: Earned 10,000,000 credits (11,458,304)PPS LLR Sapphire: Earned 20,000,000 credits (47,017,074)PSP LLR Jade: Earned 10,000,000 credits (12,715,558)SoB LLR Sapphire: Earned 20,000,000 credits (20,393,852)SR5 LLR Sapphire: Earned 20,000,000 credits (21,058,593)SGS LLR Sapphire: Earned 20,000,000 credits (21,259,616)TRP LLR Sapphire: Earned 20,000,000 credits (20,191,201)Woodall LLR Jade: Earned 10,000,000 credits (13,092,681)321 Sieve (suspended) Emerald: Earned 50,000,000 credits (55,630,889)Cullen/Woodall Sieve (suspended) Ruby: Earned 2,000,000 credits (4,178,073)Generalized Cullen/Woodall Sieve (suspended) Emerald: Earned 50,000,000 credits (56,046,594)PPS Sieve Double Gold: Earned 500,000,000 credits (521,014,891)Sierpinski (ESP/PSP/SoB) Sieve (suspended) Turquoise: Earned 5,000,000 credits (9,468,384)TRP Sieve (suspended) Jade: Earned 10,000,000 credits (10,076,645)AP 26/27 Double Gold: Earned 500,000,000 credits (500,106,006)WW Emerald: Earned 50,000,000 credits (60,756,000)GFN Double Silver: Earned 200,000,000 credits (255,353,275)PSA Double Bronze: Earned 100,000,000 credits (126,200,096)
Message 140885 - Posted: 18 Jun 2020 | 16:14:19 UTC

Good that you've already done the repaste, I like to be thorough in my posts about cleaning in case anyone non-technical wanders by, or is like my grandmother who put her PC in a closed cabinet because it was getting too loud.

Those temps are still too high, IMO, even in a 25C room. I have a couple crunchers in a closed room, and while they warm it up to 30C, they still won't get that hot.

If you aren't too worried about the longevity of the machines, it's not the end of the world as long as the fan noise doesn't bother you too much (and you can always replace them with better fans that move more air with less noise), but you probably won't see the full potential of the CPUs due to throttling. While the L9i is better than the stock cooler, it has a pretty low capacity. Have you taken the side panels off for more cool air access? I don't know how much ducting is going on inside those models, but it is an easy way for more direct cool air access.

As an extreme measure, especially since it's winter, you can always take off the panels, wrap them in bug netting, and put them outside under shelter...
____________
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Discovered 5 mega primesFound 5 primes in the 2020 Tour de PrimesFound 2 mega primes in the 2020 Tour de PrimesFound 4 primes in the 2021 Tour de PrimesFound 2 mega primes in the 2021 Tour de Primes321 LLR Sapphire: Earned 20,000,000 credits (20,020,701)Cullen LLR Sapphire: Earned 20,000,000 credits (20,174,451)ESP LLR Jade: Earned 10,000,000 credits (17,178,142)Generalized Cullen/Woodall LLR Sapphire: Earned 20,000,000 credits (20,197,125)PPS LLR Sapphire: Earned 20,000,000 credits (34,016,821)PSP LLR Sapphire: Earned 20,000,000 credits (20,372,576)SoB LLR Sapphire: Earned 20,000,000 credits (21,169,287)SR5 LLR Jade: Earned 10,000,000 credits (10,213,047)SGS LLR Jade: Earned 10,000,000 credits (13,886,073)TRP LLR Sapphire: Earned 20,000,000 credits (20,307,419)Woodall LLR Sapphire: Earned 20,000,000 credits (22,371,625)321 Sieve (suspended) Sapphire: Earned 20,000,000 credits (20,380,527)Cullen/Woodall Sieve (suspended) Gold: Earned 500,000 credits (744,531)Generalized Cullen/Woodall Sieve (suspended) Turquoise: Earned 5,000,000 credits (5,007,004)PPS Sieve Double Gold: Earned 500,000,000 credits (563,813,452)TRP Sieve (suspended) Bronze: Earned 10,000 credits (21,181)AP 26/27 Sapphire: Earned 20,000,000 credits (20,845,708)WW Double Bronze: Earned 100,000,000 credits (135,984,000)GFN Double Silver: Earned 200,000,000 credits (459,068,344)
Message 140886 - Posted: 18 Jun 2020 | 17:34:46 UTC - in response to Message 140872.

I would recommend that if you haven't dusted the machine, certainly do that. Really, everyone should, at least once every couple months, and more often if you're like me and live down the road from an active gravel quarry.

I can attest to this wisdom.
I finally just cleaned the dust out of my 9900K with 2080Ti - encouraged by this post.
Before clean I couldn't run turbo as CPU got into mid 80s C and above.
Now 80 C with turbo - not great, but just workable.
But the huge difference is GPU - I'm running PPS sieve at about 2/3 capacity - though that may have increased since I'm running turbo now.
Before - 73 C. After - 63 C
I am thinking I have been unnecessarily mean to this computer as it is 17 months old and that was it's first clean. I have 2 more computers to do. I haven't been mean to them for as long.

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Found 1 prime in the 2019 Tour de PrimesFound 5 primes in the 2020 Tour de PrimesFound 4 primes in the 2021 Tour de Primes321 LLR Ruby: Earned 2,000,000 credits (2,216,329)Cullen LLR Ruby: Earned 2,000,000 credits (2,826,433)ESP LLR Ruby: Earned 2,000,000 credits (2,253,924)Generalized Cullen/Woodall LLR Ruby: Earned 2,000,000 credits (2,218,841)PPS LLR Sapphire: Earned 20,000,000 credits (20,008,683)PSP LLR Ruby: Earned 2,000,000 credits (2,327,946)SoB LLR Ruby: Earned 2,000,000 credits (2,230,141)SR5 LLR Ruby: Earned 2,000,000 credits (2,095,507)SGS LLR Ruby: Earned 2,000,000 credits (2,037,347)TRP LLR Ruby: Earned 2,000,000 credits (4,118,961)Woodall LLR Ruby: Earned 2,000,000 credits (2,247,622)321 Sieve (suspended) Ruby: Earned 2,000,000 credits (2,279,140)Generalized Cullen/Woodall Sieve (suspended) Turquoise: Earned 5,000,000 credits (6,057,633)PPS Sieve Double Bronze: Earned 100,000,000 credits (175,851,586)AP 26/27 Ruby: Earned 2,000,000 credits (2,919,046)WW Ruby: Earned 2,000,000 credits (2,372,000)GFN Sapphire: Earned 20,000,000 credits (30,694,989)
Message 140887 - Posted: 18 Jun 2020 | 20:00:40 UTC - in response to Message 140880.


[/quote]

What form factor (e.g., mini-tower, desktop, ultrasmall, etc.)? I have a number of the 9020 models, and none run that hot even with summer weather here in North America (even the all-in-ones with i7-4770s CPUs and the small form factor desktops with i7-4790 CPUs). One thing to check...make sure that you have the latest BIOS updates for those machines. Dell's early versions did have some fan control issues that were fixed with the updates.

[/quote]

Hmm interesting about the BIOS. That's not something I've done with these PC's. That will be fun... finding the right Dell BIOS :)
These are SFF pc's (That's what Dell call them)

https://i.dell.com/sites/doccontent/shared-content/data-sheets/en/Documents/optiplex-9020-micro-technical-spec-sheet.pdf

I have run them with the side off before but I have kids and I can't put them out of reach of curious fingers so its not worth the risk.

As for the Noctua fan well... nothing else will fit those cases. As it was I learnt the hard way about Dell and their propitiatory connections (insert eye roll here)
The stupid 5 pin fan connector that is required meant I had to buy an adapter out of China and also physically snap off the raised chassis mounts that the old heatsink used to screw into. Without removing those, you can't get the motherboard back in.

Surprisingly, I don't see any drop in CPU clocks. They might run a bit faster if they were cooler but they are pretty rock solid even at high temps.

I'll check out the BIOS option over the weekend :)
Thanks for the tips.
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Found 1 prime in the 2019 Tour de PrimesFound 5 primes in the 2020 Tour de PrimesFound 4 primes in the 2021 Tour de Primes321 LLR Ruby: Earned 2,000,000 credits (2,216,329)Cullen LLR Ruby: Earned 2,000,000 credits (2,826,433)ESP LLR Ruby: Earned 2,000,000 credits (2,253,924)Generalized Cullen/Woodall LLR Ruby: Earned 2,000,000 credits (2,218,841)PPS LLR Sapphire: Earned 20,000,000 credits (20,008,683)PSP LLR Ruby: Earned 2,000,000 credits (2,327,946)SoB LLR Ruby: Earned 2,000,000 credits (2,230,141)SR5 LLR Ruby: Earned 2,000,000 credits (2,095,507)SGS LLR Ruby: Earned 2,000,000 credits (2,037,347)TRP LLR Ruby: Earned 2,000,000 credits (4,118,961)Woodall LLR Ruby: Earned 2,000,000 credits (2,247,622)321 Sieve (suspended) Ruby: Earned 2,000,000 credits (2,279,140)Generalized Cullen/Woodall Sieve (suspended) Turquoise: Earned 5,000,000 credits (6,057,633)PPS Sieve Double Bronze: Earned 100,000,000 credits (175,851,586)AP 26/27 Ruby: Earned 2,000,000 credits (2,919,046)WW Ruby: Earned 2,000,000 credits (2,372,000)GFN Sapphire: Earned 20,000,000 credits (30,694,989)
Message 140888 - Posted: 18 Jun 2020 | 20:21:01 UTC

That is one thing that that could be causing an issue that you mentioned Grebuloner.... ducting. Neither of these units has ducting directing air from the front 80mm fan to the CPU.
I know one of them DID have ducting but again, you can't fit a Noctua fan with all that plastic crap everywhere :)

I guess if you only have 1 fan, that ducting directing air over the CPU would be important :)

That could be the reason.

Oh well...as long as I don't have a fire! (Although I did buy an extinguisher the other day...just in case!) Dry powder of course.
____________

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Discovered the World's First base 25 Generalized Cullen prime!!!Discovered 31 mega primesEliminated 2 conjecture "k"sDiscovered 2 AP26sDiscovered 1 twin primeDiscovered 1 Fermat divisor2017 Tour de Primes highest prime count2017 Tour de Primes most Mountain Stage primes2018 Tour de Primes most Mountain Stage primesFound 4 primes in the 2018 Tour de PrimesFound 1 mega prime in the 2018 Tour de PrimesFound 4 primes in the 2018 Tour de Primes Mountain StageFound 1 mega prime in the 2018 Tour de Primes Mountain StageFound 1 prime in the 2019 Tour de PrimesFound 1 mega prime in the 2019 Tour de Primes2020 Tour de Primes largest primeFound 3 primes in the 2020 Tour de PrimesFound 2 mega primes in the 2020 Tour de Primes2021 Tour de Primes most Mountain Stage primesFound 9 primes in the 2021 Tour de PrimesFound 6 mega primes in the 2021 Tour de PrimesFound 3 primes in the 2021 Tour de Primes Mountain StageFound 1 mega prime  in the 2021 Tour de Primes Mountain Stage321 LLR Double Bronze: Earned 100,000,000 credits (129,186,376)Cullen LLR Double Silver: Earned 200,000,000 credits (200,281,447)ESP LLR Double Bronze: Earned 100,000,000 credits (126,297,017)Generalized Cullen/Woodall LLR Double Bronze: Earned 100,000,000 credits (123,597,455)PPS LLR Double Gold: Earned 500,000,000 credits (616,587,645)PSP LLR Double Bronze: Earned 100,000,000 credits (144,673,775)SoB LLR Double Silver: Earned 200,000,000 credits (360,962,476)SR5 LLR Double Bronze: Earned 100,000,000 credits (123,176,148)SGS LLR Double Bronze: Earned 100,000,000 credits (131,155,892)TRP LLR Double Silver: Earned 200,000,000 credits (288,859,432)Woodall LLR Double Silver: Earned 200,000,000 credits (200,946,877)321 Sieve (suspended) Double Bronze: Earned 100,000,000 credits (134,986,204)Cullen/Woodall Sieve (suspended) Sapphire: Earned 20,000,000 credits (30,879,764)Generalized Cullen/Woodall Sieve (suspended) Double Bronze: Earned 100,000,000 credits (100,428,955)PPS Sieve Double Turquoise: Earned 5,000,000,000 credits (5,158,277,853)Sierpinski (ESP/PSP/SoB) Sieve (suspended) Double Bronze: Earned 100,000,000 credits (101,857,516)TRP Sieve (suspended) Emerald: Earned 50,000,000 credits (50,936,081)AP 26/27 Double Ruby: Earned 2,000,000,000 credits (2,194,087,584)WW Double Amethyst: Earned 1,000,000,000 credits (1,644,664,000)GFN Double Turquoise: Earned 5,000,000,000 credits (6,494,888,133)PSA Double Turquoise: Earned 5,000,000,000 credits (6,051,240,385)
Message 140891 - Posted: 18 Jun 2020 | 22:19:48 UTC - in response to Message 140888.
Last modified: 18 Jun 2020 | 22:20:43 UTC

That is one thing that that could be causing an issue that you mentioned Grebuloner.... ducting. Neither of these units has ducting directing air from the front 80mm fan to the CPU.
I know one of them DID have ducting but again, you can't fit a Noctua fan with all that plastic crap everywhere :)

I guess if you only have 1 fan, that ducting directing air over the CPU would be important :)

That could be the reason.

Oh well...as long as I don't have a fire! (Although I did buy an extinguisher the other day...just in case!) Dry powder of course.


That'll be it. One of the major advantages of a Dell system (and probably HP and other major vendors) is the engineering that goes into those cases. That ducting directs air exactly where it's needed. Without it, most of the air is going where it's not needed.

I've made the mistake of removing that ducting from a Dell system. Don't do that.
____________

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Discovered 1 mega primeFound 2 primes in the 2018 Tour de PrimesFound 4 primes in the 2019 Tour de PrimesFound 3 primes in the 2020 Tour de PrimesFound 1 mega prime in the 2020 Tour de PrimesFound 4 primes in the 2021 Tour de Primes321 LLR Sapphire: Earned 20,000,000 credits (20,176,149)Cullen LLR Jade: Earned 10,000,000 credits (10,858,937)ESP LLR Jade: Earned 10,000,000 credits (11,493,104)Generalized Cullen/Woodall LLR Jade: Earned 10,000,000 credits (11,458,304)PPS LLR Sapphire: Earned 20,000,000 credits (47,017,074)PSP LLR Jade: Earned 10,000,000 credits (12,715,558)SoB LLR Sapphire: Earned 20,000,000 credits (20,393,852)SR5 LLR Sapphire: Earned 20,000,000 credits (21,058,593)SGS LLR Sapphire: Earned 20,000,000 credits (21,259,616)TRP LLR Sapphire: Earned 20,000,000 credits (20,191,201)Woodall LLR Jade: Earned 10,000,000 credits (13,092,681)321 Sieve (suspended) Emerald: Earned 50,000,000 credits (55,630,889)Cullen/Woodall Sieve (suspended) Ruby: Earned 2,000,000 credits (4,178,073)Generalized Cullen/Woodall Sieve (suspended) Emerald: Earned 50,000,000 credits (56,046,594)PPS Sieve Double Gold: Earned 500,000,000 credits (521,014,891)Sierpinski (ESP/PSP/SoB) Sieve (suspended) Turquoise: Earned 5,000,000 credits (9,468,384)TRP Sieve (suspended) Jade: Earned 10,000,000 credits (10,076,645)AP 26/27 Double Gold: Earned 500,000,000 credits (500,106,006)WW Emerald: Earned 50,000,000 credits (60,756,000)GFN Double Silver: Earned 200,000,000 credits (255,353,275)PSA Double Bronze: Earned 100,000,000 credits (126,200,096)
Message 140892 - Posted: 19 Jun 2020 | 1:07:14 UTC - in response to Message 140888.

That is one thing that that could be causing an issue that you mentioned Grebuloner.... ducting. Neither of these units has ducting directing air from the front 80mm fan to the CPU.
I know one of them DID have ducting but again, you can't fit a Noctua fan with all that plastic crap everywhere :)

I guess if you only have 1 fan, that ducting directing air over the CPU would be important :)

That could be the reason.

Oh well...as long as I don't have a fire! (Although I did buy an extinguisher the other day...just in case!) Dry powder of course.


You can make ducting out of just about anything non-conductive, just needs to get the air in the direction of the CPU cooler.

Since you have curious kids, may I suggest an inexpensive alternative to the open case? Speaker grill cloth. Cut it to size, hot glue it in place of the side panel and it acts as both mesh and a decent dust filter, while still keeping the insides hidden from prying fingers.

And good on you for the extinguisher. A home accessory everyone should have.
____________
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