20110802, 18:46  #1 
Basketry That Evening!
"Bunslow the Bold"
Jun 2011
40<A<43 89<O<88
16065_{8} Posts 
Factoring bit depth?
Hey guys,
I read somewhere that the bit depth listings for exponents was on the wiki, but I couldn't find it. Anybody have a list, or point me to one? 
20110802, 19:30  #2 
Einyen
Dec 2003
Denmark
3,037 Posts 
Here is a list from september 2009:
http://www.mersenne.org/various/math.php but I think they were recalculated more recent somewhere in the forum but can't find it. 
20110802, 19:38  #3 
Basketry That Evening!
"Bunslow the Bold"
Jun 2011
40<A<43 89<O<88
3·29·83 Posts 
I agree, because I know now that the low/mid 50,000,000's are being taken up to 71. (Saw P95 mention that in a GPU thread, but haven't seen a complete revised table since.)
Although, we could assume the same boundaries, and then just add two bits to the table there. Sound reasonable? Also, what depth are the LMH/100 million factorings going to? Last fiddled with by Dubslow on 20110802 at 19:41 
20110802, 23:37  #4 
6809 > 6502
"""""""""""""""""""
Aug 2003
101Γ103 Posts
2^{2}×3×11×71 Posts 
Try James's calculator: http://mersennearies.sili.net/factorbits.php
I don't know if it has been updated recently. 100M digit numbers are taken to 77. But those with GPU's have taken many to higher levels. From: 332192831 to 332599999 there are currently 444 at 79 bits or higher. 
20110802, 23:56  #5  
"Lucan"
Dec 2006
England
2·3·13·83 Posts 
Quote:
Quote:
The concensus is that they should be able to do 3 more bits without breaking sweat. Early days I know, but I would like to see this borne out in practice! David Last fiddled with by davieddy on 20110803 at 00:12 

20110803, 00:42  #6  
"Lucan"
Dec 2006
England
14512_{8} Posts 
Quote:
And how many exponents could those GPUs have raised to 72 bits in the 50M60M exponent range in the same time? (Yes I can work it out!) David 

20110803, 01:09  #7 
Basketry That Evening!
"Bunslow the Bold"
Jun 2011
40<A<43 89<O<88
3·29·83 Posts 
I'm asking because I just got my GTX 460 up and running. Does 7071 in 1.5 hrs, takes a couple of days on my CPU. The calculator isn't correct, it says 69 for 60,000,000 which I know isn't correct.

20110803, 06:23  #8  
"Lucan"
Dec 2006
England
14512_{8} Posts 
Quote:
So it seems that it takes a mere 12 GTX460s (24/7) to dish them out factored to 71 bits. My guess is that each of these 12 GPUs would reserve 16 exponents a day (at least). Say there are actually 40 GPUs doing TF for imminent LL tests. If they all reserved just 5 a day, they could TF the daily LL assignments from 70 to 72 bits. Doesn't this make good sense? Remember the CPU doing the LL test can't sensibly TF to 72 bits. David Last fiddled with by davieddy on 20110803 at 06:30 

20110803, 13:46  #9  
Nov 2003
1D24_{16} Posts 
Quote:
May I suggest that a different forum would be more appropriate? 

20110803, 15:47  #10 
Bamboozled!
"πΊππ·π·π"
May 2003
Down not across
2^{5}·331 Posts 

20110803, 16:08  #11 
Apr 2010
Over the rainbow
2×5×11×23 Posts 
Information and answer seem appropriate

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