OBD bookmarks

[hansl]

I am a bit new here, and was interested in the history of this project, so I just got done reading through the Report Results Here thread which contained some useful links hidden in its depths.

Hopefully the forum moderators will update this subforum's main link to a current URL soon as discussed recently in that thread, but I thought it would be helpful to list some of the other related pages here as well:

Current OBD tracker run by forums user "James Heinrich" https://www.mersenne.ca/obd

Some other stats/graphs provided forums user "lavalamp"
http://2721.hddkillers.com/billion/
http://2721.hddkillers.com/graph/
Historical mirror of last scraped (now defunct) original site: http://2721.hddkillers.com/OBDElevenSmooth/

Other higher exponent tracking (for exponents >1G, beyond which is not recorded by GIMPS/Primenet) from James' site:
https://www.mersenne.ca/tf1G.php

[Uncwilly]

Originally Posted by hansl

Hopefully the forum moderators will update this subforum's main link to a current URL

That takes an Admin level of wizardry to accomplish.

Hopefully Luigi can post a current link to a working precompiled Factor5 package. Last time I went looking for it. It was something that needed a compiler or was laking a .dll.

[hansl]

Originally Posted by Uncwilly

That takes an Admin level of wizardry to accomplish.

Hopefully Luigi can post a current link to a working precompiled Factor5 package. Last time I went looking for it. It was something that needed a compiler or was laking a .dll.

I was actually just looking around the wiki and stumbled over this: https://download.mersenne.ca/factor5

Does that help?

[ET_]

Originally Posted by hansl

I was actually just looking around the wiki and stumbled over this: https://download.mersenne.ca/factor5

Does that help?

It does. I sent James all the updated Factor5 versions I did.

the header on Factor_5.03 says "5.02", but it is a typo. The source is updated.

[kriesel]

As I understand it, Factor5 is not as fast as Ernst's Mfactor program on the same hardware. And mfaktc or mfakto are much faster on a reasonable gpu (or even somewhat old slow gpu) than either of them on a normal cpu.
Mfaktc can go to almost 2³² exponent, 95 bits factor, which seems more than enough for gigadigit candidates currently. Mfakto almost 2³² exponent, 92 bits factor, also seems enough.
Mfactor compiles in different variants, for speed, depending on available processor type and how much multiple precision may be needed, for very large exponents such as in the middle of https://www.mersenneforum.org/showpo...04&postcount=5 (some 66 to 127 bit exponent examples)

More info on software capabilities at the attachment of https://www.mersenneforum.org/showpo...91&postcount=2
Not intending to bash anyone's software or efforts, but there's a reference thread on Factor 5 at https://www.mersenneforum.org/showth...126#post532126 which advises using mfaktx or Mfactor instead for speed & cost when practical.

[Uncwilly]

Originally Posted by kriesel

As I understand it, Factor5 is not as fast as Ernst's Mfactor program on the same hardware. And mfaktc is much faster on a reasonable gpu (or even somewhat old slow gpu) than either of them on a normal cpu.

What is the current upper limit for an exponent for mfaktc? Factor5 can work on plaid exponents.

[kriesel]

(updated version of my previous post, past the edit expiration time)
As I understand it, Factor5 is not as fast as Ernst's Mfactor program on the same hardware. And mfaktc or mfakto are much faster on a reasonable gpu (or even somewhat old slow gpu) than either of them on a normal cpu.
Mfaktc can go to almost 2³² exponent (1.29+ gigadigits), 95 bits factor, which seems more than enough for gigadigit candidates currently. Mfakto almost 2³² exponent, 92 bits factor, also seems enough.
Mfactor compiles in different variants, for speed, depending on available processor type and how much multiple precision may be needed, for very large exponents such as in the middle of https://www.mersenneforum.org/showpo...04&postcount=5 (some 66 to 127 bit exponent examples) or larger; 2, 3,4, n word precision.

More info on software capabilities at the attachment of https://www.mersenneforum.org/showpo...91&postcount=2
Not intending to bash anyone's software or efforts, but there's a reference thread on Factor 5 at https://www.mersenneforum.org/showth...126#post532126 which advises using mfaktx or Mfactor instead for speed & cost when practical.

Mfaktc RTX 2080 Super experience: (1 of 3 instances running together on different assignments)

[Fri Aug 21 02:25:10 2020]
UID: Kriesel/dodo-rtx2080super, no factor for M112062857 from 2^75 to 2^76 [mfaktc 0.21 barrett76_mul32_gs]
[Sat Aug 22 15:13:24 2020]
UID: Kriesel/dodo-rtx2080super, no factor for M3321933179 from 2^84 to  2^85 [mfaktc 0.21 barrett87_mul32_gs]

Elapsed time 84 to 85 bits, 36:48:14 as 1 of 3 instances; estimated ~12.3 hours as a solo instance. A spot check of the logs for equality of GhzD/day among the 3 instances during that period shows they're within ~3%. Power was limited to125W total for summer running.