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Old 2021-05-29, 20:25   #17
drkirkby
 
"David Kirkby"
Jan 2021
Althorne, Essex, UK

44710 Posts
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Quote:
Originally Posted by tuckerkao View Post
I hope that the DDR5 Memory modules will be available for the compatible motherboards and CPUs by mid year 2022. If the total memory capacities reaches 512 gigabytes per machine, the P-1 factoring should be under 2 hours for most exponents under 200M.
To give just one data point, for an exponent of 108,792,767 the P-1 factoring is only using 321 GB RAM despite I had given it access to 370 GB. I don't know how that would scale to exponent of 200 M, but it would not totally surprise me if more than 512 GB could be used.
Code:
[Worker #2 May 29 20:18] M108792767 stage 1 complete. 2678570 transforms. Time: 2019.648 sec.
[Worker #2 May 29 20:18] Starting stage 1 GCD - please be patient.
[Worker #2 May 29 20:19] Stage 1 GCD complete. Time: 47.641 sec.
[Worker #2 May 29 20:19] Available memory is 376728MB.
[Worker #2 May 29 20:19] D: 2730, relative primes: 7192, stage 2 primes: 3211863, pair%=95.71
[Worker #2 May 29 20:19] Using 328771MB of memory.
[Worker #1 May 29 20:19] Iteration: 76800000 / 103866121 [73.94%], ms/iter:  1.492, ETA: 11:13:15
[Worker #1 May 29 20:22] Iteration: 76900000 / 103866121 [74.03%], ms/iter:  1.488, ETA: 11:08:52
[Worker #1 May 29 20:24] Iteration: 77000000 / 103866121 [74.13%], ms/iter:  1.560, ETA: 11:38:31
[Worker #1 May 29 20:24] Gerbicz error check passed at iteration 77000000.
[Worker #2 May 29 20:26] Stage 2 init complete. 75668 transforms. Time: 425.106 sec.
Be aware that server grade CPUs will most likely require ECC RAM, and that is significantly more expensive than RAM without error correction. Dell want just over £500 ($709 USD) for a single 32 GB stick of DDR4 ECC RAM for this Dell 7920 tower workstation. Even third party (Kingston) RAM is about £180 for 32 GB from a reseller. A distributor is a bit cheaper, but they can't currently get any 32 GB RDIMMs from Kingston.

Dave

Last fiddled with by drkirkby on 2021-05-29 at 20:42
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