mersenneforum.org  

Go Back   mersenneforum.org > Great Internet Mersenne Prime Search > Software

Reply
 
Thread Tools
Old 2009-08-17, 22:02   #1
g0ods
 
g0ods's Avatar
 
Mar 2005
Malton, England

110002 Posts
Default Dual Core P95 64Bit P4 Equivalent problem

Hi there,
I have installed P95 64bit on my Mum's PC and for some reason, despite being configured as running for 24 hours, the server thinks the P4 equivalent is about 0.749GHz. Can someone point me in the direction of how to fix this, or is it a bug?

Regards,
g0ods
Attached Thumbnails
Click image for larger version

Name:	Dual_Core_Gimps.png
Views:	201
Size:	14.7 KB
ID:	3994  
g0ods is offline   Reply With Quote
Old 2009-08-17, 23:08   #2
Kevin
 
Kevin's Avatar
 
Aug 2002
Ann Arbor, MI

433 Posts
Default

Quote:
Originally Posted by g0ods View Post
Hi there,
I have installed P95 64bit on my Mum's PC and for some reason, despite being configured as running for 24 hours, the server thinks the P4 equivalent is about 0.749GHz. Can someone point me in the direction of how to fix this, or is it a bug?

Regards,
g0ods
It's fine how it is for now. The P4 equivalent is an estimate of how fast of a Pentium 4 you'd need to complete the amount of work that computer has returned over the same time frame. Work in progress doesn't get counted. Within a period of 24 hours, you probably haven't completed and returned a significant amount of work yet, and won't get a very good estimate. It'll take some time for you to return enough work before the P4 estimate will more or less stabilize at something reasonable.
Kevin is offline   Reply With Quote
Old 2009-08-18, 08:29   #3
g0ods
 
g0ods's Avatar
 
Mar 2005
Malton, England

23×3 Posts
Default

Well, my point was that because the P4 Equivalent is so low the Primenet server is assigning TF work, when I would have thought that a Dual Core @2.5GHz would be suitable for at least Double Check assignemnts if not then even First Time LL tests. So what I am wondering is why is the P4 Equiv so low?

M.
g0ods is offline   Reply With Quote
Old 2009-08-18, 12:09   #4
garo
 
garo's Avatar
 
Aug 2002
Termonfeckin, IE

53148 Posts
Default

Hmmm. That does not make sense. Maybe a bug in Prime95? I would manually set the work preference to DC or LL. That CPU is wasted on TF.

Could you run a benchmark and post the results here?

Last fiddled with by garo on 2009-08-18 at 12:10
garo is offline   Reply With Quote
Old 2009-08-18, 12:10   #5
markr
 
markr's Avatar
 
"Mark"
Feb 2003
Sydney

3×191 Posts
Default

Would thermal throttling do that? Is it a laptop, or possibly accumulated some dust in the innards?
markr is offline   Reply With Quote
Old 2009-08-18, 14:51   #6
lfm
 
lfm's Avatar
 
Jul 2006
Calgary

52×17 Posts
Default

Quote:
Originally Posted by g0ods View Post
Well, my point was that because the P4 Equivalent is so low the Primenet server is assigning TF work, when I would have thought that a Dual Core @2.5GHz would be suitable for at least Double Check assignemnts if not then even First Time LL tests. So what I am wondering is why is the P4 Equiv so low?

M.
Ya some of those "p4 equivalent" ratings are kinda wild. Don't worry about it tho. It doesn't really reflect anything significant. Your machine will still get all the credit it is due.

If you prefer some other work use the preferences to change what is assigned.
I have one of those Intel Pentium Dual Core (45 nm, E5200) at 2.5 Ghz too and the rating is whacky for mine too. The rating may get somewhat closer over time as you return some results and whatnot, not sure. I set mine up to run first time LL tests and its doing fine. (About 40 days per test per core.)
lfm is offline   Reply With Quote
Old 2009-09-14, 19:37   #7
g0ods
 
g0ods's Avatar
 
Mar 2005
Malton, England

23×3 Posts
Default

The E5200 is happily doing DCs, and fingers crossed the server will assign a 1st time test when a DC nears completion. I will run a benchmark, next time I visit Mum, and will post it here.

M.
g0ods is offline   Reply With Quote
Old 2009-09-15, 06:55   #8
S45653
 
Oct 2008

23 Posts
Default

Quote:
Originally Posted by garo View Post
That CPU is wasted on TF.
Well..., isn't trial factoring the only GIMPS work type that actually benefits from running under 64-bit OS compared to 32-bit on the same hardware?
See this thread.
S45653 is offline   Reply With Quote
Old 2009-09-15, 08:17   #9
CADavis
 
CADavis's Avatar
 
Jul 2005
Des Moines, Iowa, USA

17010 Posts
Default

Quote:
Originally Posted by S45653 View Post
Well..., isn't trial factoring the only GIMPS work type that actually benefits from running under 64-bit OS compared to 32-bit on the same hardware?
Nope. In version 25.9 and on, On core2, core i7, and phenom cpus George has used the 64-bit mode to improve performance up to ~%13.

Quote:
Originally Posted by Prime95 View Post
Performance increases for the 64-bit version by taking advantage of the eight extra SSE2 registers. The 32-bit version may also be a bit faster by taking advantage of the Core 2 architecture. The FFT code was originally optimized for the Pentium 4 where instructions like "movapd reg,reg" take 6 clocks and should be avoided, whereas on Core 2 the same instruction uses just 1 clock cycle and improves scheduling. The 32-bit version may be slightly faster or slower on the Pentium 4, but not enough to worry about.
CADavis is offline   Reply With Quote
Old 2009-09-15, 14:12   #10
lycorn
 
lycorn's Avatar
 
Sep 2002
Oeiras, Portugal

101110000002 Posts
Default

Trial Factoring is the type of work that by far benefits the most from 64-bit OSs (of course using the 64-bit version of the Prime95 executable), but particularly on AMD CPUs (on Athlon64s, the improvement was in the order of 100%). On Intel CPUs, including the Core 2 line, this difference is not so noticeable, and IIRC would be smaller for TFing over 65 or 66 bits.
Now even if TF benefits a lot from 64-bits, the CPU mentioned is a very capable one for LL assignments, which means that it´s better to leave TF work for slower machines. Also because the current status of the project is such that we are "overpowered" for TF, and we are lacking LL, and particularly DC, horsepower, so powerful machines are most welcome for those tasks.

Last fiddled with by lycorn on 2009-09-15 at 14:19
lycorn is offline   Reply With Quote
Reply



Similar Threads
Thread Thread Starter Forum Replies Last Post
An equivalent problem for factorization of large numbers HellGauss Math 5 2012-04-12 14:01
Dual Core to Quad Core Upgrade Rodrigo Hardware 6 2010-11-29 18:48
Importance of dual channel memory for dual core processors patrik Hardware 3 2007-01-07 09:26
Intel e6600 Dual Core Problem - How to use both cores with Prime95? Shoallakeboy Hardware 2 2006-11-06 17:55
P4 dual core problem tholloway Hardware 5 2006-10-28 20:16

All times are UTC. The time now is 00:03.


Sat Jul 17 00:03:46 UTC 2021 up 49 days, 21:51, 1 user, load averages: 1.10, 1.43, 1.46

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.