Please visit donation page to help the project cover running costs for this month

Toggle Menu

Join PrimeGrid

Returning Participants


Leader Boards



1) Message boards : Seventeen or Bust : Are people even sure 78557 is the smallest k? (Message 140243)
Posted 135 days ago by dukebg
A more on-topic message.
I started typing a message about why would the covering set from the dual problem automatically become a covering set in the "non-dual" problem. But then I figured it out on my own. Fun math.
2) Message boards : Seventeen or Bust : Are people even sure 78557 is the smallest k? (Message 140241)
Posted 135 days ago by dukebg
Ravi Fernando wrote:
So e.g. k=67607 is known to produce at least two primes (or maybe PRPs, not sure if they've been tested with ECPP): 2^16389 + 67607 and 2^46549 + 67607.

It appears the first of these two numbers was proven prime just 2 months ago:

Oh, that was most likely a lucky happenstance. Masaki UKAI runs ECPP basically for all PRPs in FDB of that size. 4.9K dd is pretty small, just few hours on modern hardware. I don't think they ran this exact number on purpose.
3) Message boards : Generalized Fermat Prime Search : GFN-16 MEGA Prime Search starts March, 14, 2019 (Message 139718)
Posted 161 days ago by dukebg
I thought we were already in the cleanup since the finds.
4) Message boards : General discussion : Potential for cheap supercomputer array for PrimeGrid (Message 133114)
Posted 370 days ago by dukebg
This would be great for people who want to help but can't directly volunteer their machines and would rather donate directly.

They could just... donate directly then.
5) Message boards : General discussion : Encryption / Cybersecurity (Message 133113)
Posted 370 days ago by dukebg
My main intention with PrimeGrid is to help bolster cybersecurity. Does anyone have any recommendations for which subprojects are most likely to discover primes useful for encryption? Thanks!

absolutely none.
6) Message boards : Project Staging Area : multiple jobs assigned to single processors (Message 132572)
Posted 387 days ago by dukebg
Or is the problem that the server thinks it sent more than one task to you, but you only have one of the tasks on your computer?

If that's the problem, just ignore it. Only the tasks actually received by your computer will be run on your computer, and the others will time out and then be sent out again.

This, but it happened for everybody who received tasks at that time.
7) Message boards : Generalized Fermat Prime Search : DO YOU FEEL LUCKY? (Message 131626)
Posted 422 days ago by dukebg
how much faster GPU would have been counting … if my ask/favor wolud have been set

Next to none at all, I believe. Because, as dthonon wrote:

I believe that geneferocl will use as much CPU power as needed to get the GPU active. And its runs with a higher priority than llr tasks, so it is not slowed down by CPU only projects.
8) Message boards : Generalized Fermat Prime Search : DO YOU FEEL LUCKY? (Message 131620)
Posted 422 days ago by dukebg
In BOINC it is possible to specify how many CPU cores does a GPU task take using app_config.xml. This is something the user does himself.

See here, the option is called cpu_usage
9) Message boards : Problems and Help : Suddenly "error while computing" (Message 131542)
Posted 425 days ago by dukebg
After running PPS Sieve and AP 27 for many wus with rarely ever having an error I switched last night and started running GFN 15, 16 and 17 low.

All 28 wus failed.

My desktop is running Win 7 and has dual GeForce GTX 970 cards.

The only recent change made was an update to driver on May 5 2019.

Help please.

AT Hiker

Most likely you've installed a driver that doesn't have OpenCL libraries. You need a driver that has OpenCL libraries for GFN projects (but not PPS Sieve, it's CUDA).
10) Message boards : Problems and Help : How to only download one WU at a time? (Message 131539)
Posted 425 days ago by dukebg

|---| |---| |---| |---| |---| |---|


|----------------------| |----------------------| |----------------------| |----------------------| |----------------------| |----------------------|

I too would like to find a way for the client to download only one task when in MT mode with zero resource share, so that each task us returned as fast as possible, and the best possibility of being first. As far as I can tell, this is not possible.

|---| |---| |---| |---| |---| |---|

Calculations on the same cores cannot physically run at the same time, they are just going to be waiting for their time on the CPU core (AVX unit or elsewhere) in a queue (CPU time scheduling + fighting for CPU cache space). So yes, this is impossible and kinda weird why would you imagine it being possible. Multithreading is using 6x calculations speed.

Here's a revision of your diagram

|666| |666| |666| |666| |666| |666|


|1111111111111111111111| |1111111111111111111111| |1111111111111111111111| |1111111111111111111111| |1111111111111111111111| |1111111111111111111111|

You cannot go more than 6 at the same time verically.

Next 10 posts
[Return to PrimeGrid main page]
Copyright © 2005 - 2020 Rytis Slatkevičius (contact) and PrimeGrid community. Server load 3.80, 3.55, 3.46
Generated 26 Sep 2020 | 18:16:21 UTC