PrimeGrid - We found a Prime!

Good at maths? Then why not figure on helping these projects - Gerasim, GPUGrid, Moo! Wrapper, NFS, NumberFields, ODLK, PrimeGrid, Rakesearch, SRBase
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chriscambridge
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PrimeGrid - We found a Prime!

Post by chriscambridge »

Dear AP finder,

Congratulations! Our records indicate that a computer registered by you has found a unique Arithmetic Progression of primes of length 20. This computer is assigned to the AP27 project. Since primes found in this subproject are not large enough to report to the Top 5000 Primes List, your AP20 sequence is visible immediately.

Workunit 519886161 : 88594326586038017+25304016*23#*n for n=0..19
UBT - Mikee
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Re: PrimeGrid - We found a Prime!

Post by UBT - Mikee »

Hi

4:44 in the morning? I thought I was up early at 5:15!

Well done! Not done Primegrid for years but getting, even a minor one, is quite an achievement.

Mike
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chriscambridge
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Re: PrimeGrid - We found a Prime!

Post by chriscambridge »

Thanks.

Yeah sometimes I get up quite early.. obviously just to check to see if I have found a prime.. :?

And if anyone is wondering how we found a prime when we have not crunched using our Chris Cambridge account in quite a while.. We are now have now retired that account and are using a different one.

New account has:

2 x i7 4790 (16 logical processors, 4 cores per CPU)
1 x dual Xeon E5-2670 (32 logical processors, 8 cores per CPU)
2 x Xeon E5-2683 V3 (56 logical processors, 14 cores per CPU)
2 x dual Xeon E5620 (32 logical processors, 4 cores per CPU) [*retired due to excessive TDP]

2 x GTX 1080
3 x GTX 970
1 x GTX 750 TI
Last edited by chriscambridge on Sun Jun 04, 2017 4:58 am, edited 3 times in total.
Woodles
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Re: PrimeGrid - We found a Prime!

Post by Woodles »

Well done Chris (Just getting up now :oops: :D)

Nice set of hosts there (so you got a 1080 after all?)
chriscambridge
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Re: PrimeGrid - We found a Prime!

Post by chriscambridge »

Thanks; although its far more than I can actually afford to run 24-7 in terms of electricity. So it gets turned on bit by bit.. Also unless I need to power crunch the older E5620 do not get used due to not being that efficient in terms of TDP.

Yeah I got the 1080, £400 was far too good a deal to be missed. Even though 1080's have now crashed in price and you can pick up a new one for under £500.

Because I am using 4 PCIE slots in the GPU Rack and only one of them can run at x16 speed, the other three at x8, so It makes sense to have one 1080 and three 970s.

EG:

1080 running in x16 slot @ x16 speeds via Gen3, and three 970s in x16 slots @ x8 speeds via Gen3 - using the X99 mobo with 4 PCIE slots, and the 40 PCIE lanes via the V3 Xeon

I also managed to get the x16 to x16 powered risers, so that means I have the full x16 data bus going from mobo to card for the GPU rack.

I am going to be doing the final build on it in the next few days now I have a new ATX box to move the i7 into.
Woodles
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Re: PrimeGrid - We found a Prime!

Post by Woodles »

It does build up a bit doesn't it.

I might have to have another look at the 1080s then, I hadn't realised that they'd dropped by so much.

I've almost given up the idea of a GPU rack for now, I found that PCIE 2.0 @ x1 bus width (which was what the spare motherboard I had for the rack produced) failed about 25% of my Collatz WUs. It might be alright for Bitcoin mining but doesn't seem suitable for BOINC GPU crunching. If I need to get a new motherboard to run the GPU rack, then I might as well get one that can take the GPUs directly since they've all found distributed homes in my other hosts and it would only be for new GPUs.

Good luck with your i7/ATX build.

Mark
chriscambridge
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Re: PrimeGrid - We found a Prime!

Post by chriscambridge »

Hi Mark,

Two of the fastest 1080's, Gigabyte G1 and MSI Armor, for under £480/£490

http://www.ebuyer.com/store/Components/ ... e-GTX-1080
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