The search up to 10^21

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Sergei Chernykh
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Message 1246 - Posted: 25 Oct 2019, 13:11:37 UTC

The search up to 1021 has started! Over 50,000 new amicable pairs have been found in the first few days.

Due to the huge size of search space, first stage of the search will only look for all amicable pairs where smaller number is of the form 3N*...*p where N > 0 and p < 1011. I expect that this will find 2-3 million new amicable pairs in a year or so.

Note that system memory requirements are higher now because all prime numbers < 1011 need to be stored in memory for the search.
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Jonny

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Message 1248 - Posted: 25 Oct 2019, 16:58:36 UTC - in response to Message 1246.  

I'm quite excited to be a part of the team, in searching for endless numbers. Let the GPU's wind up!


--Jonny Mac
@YT Jonny Macenroe
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dannyridel
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Message 1259 - Posted: 26 Oct 2019, 2:40:11 UTC

Does this app use a different algorithm as before?
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archeye

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Message 1261 - Posted: 26 Oct 2019, 9:26:37 UTC - in response to Message 1246.  

Note that system memory requirements are higher now because all prime numbers < 1011 need to be stored in memory for the search.


This is useful to know but if you were able to give an example for memory needed that would be better.

For example, Boinc Manager, Disc tab shows Amicable numbers only using 1.73 Mb as I have no tasks running atm.

I allocate 20gb disc space to Boinc and have currently 15Gb free for Boinc to use.

I have 32Gb Ram and allow,
When computer is in use, use at most 50 %
When computer is not in use, use at most 90 %
Leave non-GPU tasks in memory while suspended
Page/swap file: use at most 75 %

While I guess my settings and available Ram availability is ok it would be nice to have an idea of the current potential requirements for Amicable tasks :)
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Profile JohnMD
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Message 1269 - Posted: 28 Oct 2019, 12:57:50 UTC - in response to Message 1246.  

Note that system memory requirements are higher now because all prime numbers < 1011 need to be stored in memory for the search.

Resources per CPU WU are doubled - both memory and CPU-cycles. Shouldn't credit follow suit ?
Can't the allocated cores share a single copy of primes in memory ?
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Sergei Chernykh
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Message 1278 - Posted: 30 Oct 2019, 16:53:06 UTC

Attention!
There was a bug in GPU version for 1021 search that caused invalid results after resuming from checkpoint in some cases, so I had to fix it and restart the search from the beginning.
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bluestang

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Message 1279 - Posted: 30 Oct 2019, 22:54:58 UTC - in response to Message 1278.  

Anything us users need to do on our end? Abort tasks, application file, reset project?
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Sergei Chernykh
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Message 1281 - Posted: 30 Oct 2019, 23:09:57 UTC - in response to Message 1279.  

No, old tasks will just run out soon. You might abort tasks that use v3.01 GPU application, but it's safe to just leave them running without pausing/resuming.
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bluestang

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Message 1282 - Posted: 30 Oct 2019, 23:26:58 UTC - in response to Message 1281.  

Ok, good to know. Also, thanks for the hard work and staying on top of things. Not many Project Admins respond as quick as you do. It's great to see!
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Message 1307 - Posted: 16 Nov 2019, 20:08:52 UTC

Is there a minimum requirement for GPU RAM ?
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Sergei Chernykh
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Message 1308 - Posted: 16 Nov 2019, 22:49:06 UTC - in response to Message 1307.  

It should work on 1GB GPUs, but I haven't tested it. You'll probably need to reduce kernel size to the minimum.
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