20111107, 23:02  #23 
Nov 2010
Germany
3×199 Posts 
mfakto update, please
Dubslow mentioned I might want to comment on the mfaktopart of the pdf ... sorry I did not take part in that earlier.
And indeed, the "DO NOT SUBMIT “NO FACTOR” RESULTS YET" statement is a bit outdated. Apart from the bug with version 0.08 that may lead to missed factors < 2^{48}, there's no known reason for not reporting all results. Regarding the Factor size: There is no lower limit for the factors, so for mfaktc this should just read "Factor size <= 2^{95} ". mfakto does not yet have the 95bit kernel, so for mfakto the limit is "Factor size <= 2^{92} ". As an estimated GIMPS score you can use (maybe I should test that some day): roughly 60 GHz days/day on HD5770 & 2 CPU cores This is also a bit misleading: "mfakto works best on large exponents as the sieving (CPU) part stays constant with larger numbers." mfakto (and mfaktc) are more efficient with larger assignments. This does not mean larger exponents, but "more work" or "longer runtime per class", generally bigger bit ranges. The reason is a certain onetime initialization effort per class  no matter if the class will just test 1 million factor candidates or 1 billion. In the first case, the onetime effort may account for, say, 75% of the sieving effort, in the latter case just 0.3%. Plus there is an average of half a block wasted for each class. If the class consists of only one block, that's 50%, for 1000 blocks it's just 0.05%. Last fiddled with by Bdot on 20111107 at 23:41 Reason: large exponents vs. large assignments 
20111108, 06:10  #24 
Dec 2009
Peine, Germany
331 Posts 
Thanks
I'm going to integrate this information asap.

20111108, 07:14  #25 
6809 > 6502
"""""""""""""""""""
Aug 2003
101×103 Posts
2·5·13·73 Posts 

20111108, 08:39  #26 
Nov 2010
Germany
3·199 Posts 
I just checked the crunchingpower of my HD5770box. The last 24 hrs returned 96.6 GHzdays, using 3 CPUcores. So I guess mentioning 90 GHzdays/day with 2 cores should be quite safe.

20111108, 21:26  #27 
Dec 2009
Peine, Germany
331 Posts 
GPU Computing Guide Update to v 0.06
This is a replacement for 0.05a. Please review.
Several minor changes:
Last fiddled with by Brain on 20120805 at 10:15 
20111109, 04:31  #28 
Romulan Interpreter
Jun 2011
Thailand
9,377 Posts 

20111112, 11:42  #29  
Bamboozled!
"𒉺𒌌𒇷𒆷𒀭"
May 2003
Down not across
2·5,323 Posts 
Quote:
As a rule, GPUs are good at computation, poor at memory access and lousy at I/O compared with CPUs. The sieving phase is very heavily memory bound ... Paul 

20111113, 06:17  #30 
Romulan Interpreter
Jun 2011
Thailand
9377_{10} Posts 
Thanks for the answer, it was more like a curiosity, my understanding of NFS is almost zero at this time.

20111113, 06:26  #31  
Basketry That Evening!
"Bunslow the Bold"
Jun 2011
40<A<43 89<O<88
3×29×83 Posts 
Quote:
or some other mod... (and the other FAQ thread as well) 

20120111, 22:05  #32 
Basketry That Evening!
"Bunslow the Bold"
Jun 2011
40<A<43 89<O<88
1C35_{16} Posts 
Looking for an old post, found that this PDF is still v.06, while the other FAQ has v.07.

20120113, 09:27  #33 
Nov 2010
Germany
3·199 Posts 
BTW, mfakto 0.10 / 0.10p1 solved the issues with the latest Catalyst drivers. 11.10 to 11.12 are tested well.

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