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Windows 10x64 latest update
Latest Boinc
No AppConfig all stock PrimeGrid settings
I have a spare i5 4-core that is having a strange issue. It's only using half of my CPU. I have multi-core / threading turned off but its still shows 4 tasks using 46% of my CPU.
I tried setting each task affinity per core too and that did not fix the issue.
Here is a screen shot:
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streamVolunteer moderator
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It's something strange. I've never encountered such behavior before.
Another strange thing is that Windows says "Speed - 1.34 GHz" although CPU should run at 2.90 GHz on full load.
Did you checked CPU core temperature? There are lot of small freeware utilities, like SpeedFan. May be CPU is overheating and heavily thermal throttled. Theoretically, OS also may do some throttling - for example, modern Linux distributions will automatically insert idle CPU cycles if core temperature exceeds 80C.
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GDBSend message
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Each MEGA task uses 2 MB L3 cache. Since you're running 4 MEGA tasks, that's 8 MB of L3 demand.
You only have 6 MB of L3 available. You're thrashing your L3 cache. That means every MEGA
memory access has to wait for a read of RAM memory (very slow vs. L3 cache).
Your MEGA data never has a chance to be reused from L3 cache before
it's knocked out of L3 cache by another MEGA data access.
That means you shouldn't run more than 1 MEGA with 4 threads (CPUs),
or 2 MEGAs with 2 threads (CPUs) each. By doing this, your CPUs will be
close to 100% and you'll do at least twice as many MEGA tasks per day.
Since you're running other things (which use L3 too), I'd recommend 1 MEGA with 4 threads.
If you weren't running other things, 2 MEGAs with 2 threads might be slightly faster.
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That means you shouldn't run more than 1 MEGA with 4 threads (CPUs),
or 2 MEGAs with 2 threads (CPUs) each. By doing this, your CPUs will be
close to 100% and you'll do at least twice as many MEGA tasks per day.
Since you're running other things (which use L3 too), I'd recommend 1 MEGA with 4 threads.
If you weren't running other things, 2 MEGAs with 2 threads might be slightly faster.
While this is generally good advice for most other CPU apps, I don't believe GFN supports multithreading (except for GFN-21). |
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 Michael Goetz Volunteer moderator
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Each MEGA task uses 2 MB L3 cache. Since you're running 4 MEGA tasks, that's 8 MB of L3 demand.
You only have 6 MB of L3 available. You're thrashing your L3 cache. That means every MEGA
memory access has to wait for a read of RAM memory (very slow vs. L3 cache).
Your MEGA data never has a chance to be reused from L3 cache before
it's knocked out of L3 cache by another MEGA data access.
That means you shouldn't run more than 1 MEGA with 4 threads (CPUs),
or 2 MEGAs with 2 threads (CPUs) each. By doing this, your CPUs will be
close to 100% and you'll do at least twice as many MEGA tasks per day.
Since you're running other things (which use L3 too), I'd recommend 1 MEGA with 4 threads.
If you weren't running other things, 2 MEGAs with 2 threads might be slightly faster.
This is all true, but it is off-topic and doesn’t answer his question. Cache misses are too low level a concept to be reflected in the Windows Task Manager. It does not explain why he’s seeing only 50% utilization.
TThrottle and similar utilities/tools/features could cause this, however. A clue here is the very low clock speed. The device is likely overheating, and something may be idling the CPU in order to keep the temperature down.
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Michael GoetzVolunteer moderator
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That means you shouldn't run more than 1 MEGA with 4 threads (CPUs),
or 2 MEGAs with 2 threads (CPUs) each. By doing this, your CPUs will be
close to 100% and you'll do at least twice as many MEGA tasks per day.
Since you're running other things (which use L3 too), I'd recommend 1 MEGA with 4 threads.
If you weren't running other things, 2 MEGAs with 2 threads might be slightly faster.
While this is generally good advice for most other CPU apps, I don't believe GFN supports multithreading (except for GFN-21).
He is running PPS-MEGA on the CPU.
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GDBSend message
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I recommend app "Core Temp" for tracking your CPU temps.
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If the temperature reading on the GTX 980 (64C) is anywhere close to correct, then heating is unlikely to be the culprit here.
First thing I would look at is the power settings in the control panel. Win 10 updates have been known to reset these into a power reduced mode when an "s" chip is detected by the OS during the update. Make sure it is on the performance setting.
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If the temperature reading on the GTX 980 (64C) is anywhere close to correct, then heating is unlikely to be the culprit here.
why? cpu and gpu temps aren't linked. |
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If the temperature reading on the GTX 980 (64C) is anywhere close to correct, then heating is unlikely to be the culprit here.
why? cpu and gpu temps aren't linked.
An overheating CPU tends to stress the system and tick up heat everywhere. 64C is fairly cool on a crunching GTX 980 in general, and especially in a dual-GPU set up. An overheating CPU should raise the ambient temps enough to push that GPU over 70C when it is crunching GFN.
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If the temperature reading on the GTX 980 (64C) is anywhere close to correct, then heating is unlikely to be the culprit here.
why? cpu and gpu temps aren't linked.
An overheating CPU tends to stress the system and tick up heat everywhere. 64C is fairly cool on a crunching GTX 980 in general, and especially in a dual-GPU set up. An overheating CPU should raise the ambient temps enough to push that GPU over 70C when it is crunching GFN.
A fan/radiator which fall down from CPU is a simplest example when CPU will be immediately exposed to huge local overheating and throttled down, not affecting rest of the system. An improperly mounted radiator (e.g. with one mounting leg broken, or mounted awry - without contact with CPU cover) will lead to same effect.
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Thank you for the suggestions everyone. I'm going to tears down the system clean it and re-apply thermal paste within the next couple of days. I'll report back. |
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I replaced the bad thermal paste job and got rid of that useless GTX770 and everything is working as intended now at 100% CPU usage.
CPU is also holding at 2.89Ghz |
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mikey
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I replaced the bad thermal paste job and got rid of that useless GTX770 and everything is working as intended now at 100% CPU usage.
CPU is also holding at 2.89Ghz
WOO HOO!!! |
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