Iteration times slow compared to benchmark

cd1940 · 2004-07-05, 05:06

Hello,

It seems like my machine is taking too long to complete the primality test and I was hoping for some guidance on how to correct this.

I looked at http://mersenne.org/bench.htm and entered the specs for my mahcine (P4 2.8 ghz, running 24hrs) using Prime95 version 23.8.1 and it says and that it should take about 21 days to complete a number of that size (see below) but mine has been running for 38 days and is not even half the way thru. My machine has a iteration time 0.162 compared with the bench mark of 0.058. My Task manager says CPU utilization is: system idle process 88 and Prime95 12. I have not made any changes to Processor Affinity.

prime fact current days exponent bits iteration run / to go / exp date updated date assigned computer ID Mhz Ver

24634549 68 11770624 38.3 17.0 77.0 05-Jul-04 04:16 27-May-04 22:59 storm 2793 v19/v20

any ideas? thanks for your time.

optim · 2004-07-05, 07:47

maybe you have some virus/trojan/worm problems? Some viruses have this behaviour (stealing CPU cycles). Please check your Windows system with a good antivirus (such as PCcillin - www.antivirus.com or Panda www.pandasoftware.com ) or switch to Linux

However, I have seen viruses to steal cycles through svchost process but not through the idle process. Perhaps you should check your HyperThreading too?

Prime95 · 2004-07-05, 15:39

Have you looked in task manager to see if prime95 is getting 95+% of the CPU time? Have you disabled screen savers and power save features?

Joe O · 2004-07-05, 16:08

Hey folks cd1940 said:
My Task manager says CPU utilization is: system idle process 88 and Prime95 12.

TauCeti · 2004-07-05, 17:55

Hmm, strange one.

Some ideas: Do you use Windows XP?

Does your System idle process (check in task manager) only use a tiny amount of memory (20k on my machine)? Just to make sure it is really the 'normal' idle process and not some disguised malware.

You could raise prime95 priority with the advanced/priority command. Try setting it to '9'. You find the password to enable those advanced functions in the readme.txt (section ADVANCED MENU)

If you use win XP you can also try to boot in safe mode and check if the situation stays the same.

I thought about the possibility that your cooling solution is malfunctionung (can you check the CPU temperature?) but i don't think you would get high idle time that way.

but: can you run some benchmark like Sysmark or SiSoft Sandra? Just to make sure your system performs ok in general.

Ok, a lot of wild guesses here but maybe a lucky hit...

Tau

2004-07-05, 05:06	#1
cd1940 Feb 2004 3 Posts	Iteration times slow compared to benchmark Hello, It seems like my machine is taking too long to complete the primality test and I was hoping for some guidance on how to correct this. I looked at http://mersenne.org/bench.htm and entered the specs for my mahcine (P4 2.8 ghz, running 24hrs) using Prime95 version 23.8.1 and it says and that it should take about 21 days to complete a number of that size (see below) but mine has been running for 38 days and is not even half the way thru. My machine has a iteration time 0.162 compared with the bench mark of 0.058. My Task manager says CPU utilization is: system idle process 88 and Prime95 12. I have not made any changes to Processor Affinity. prime fact current days exponent bits iteration run / to go / exp date updated date assigned computer ID Mhz Ver 24634549 68 11770624 38.3 17.0 77.0 05-Jul-04 04:16 27-May-04 22:59 storm 2793 v19/v20 any ideas? thanks for your time.

2004-07-05, 07:47	#2
optim Nov 2003 European Union 2³·13 Posts	virus? maybe you have some virus/trojan/worm problems? Some viruses have this behaviour (stealing CPU cycles). Please check your Windows system with a good antivirus (such as PCcillin - www.antivirus.com or Panda www.pandasoftware.com ) or switch to Linux However, I have seen viruses to steal cycles through svchost process but not through the idle process. Perhaps you should check your HyperThreading too? Last fiddled with by optim on 2004-07-05 at 07:50

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2004-07-05, 15:39	#3
Prime95 P90 years forever! Aug 2002 Yeehaw, FL 5×11×137 Posts	Have you looked in task manager to see if prime95 is getting 95+% of the CPU time? Have you disabled screen savers and power save features?

2004-07-05, 16:08	#4
Joe O Aug 2002 3·5²·7 Posts	Hey folks cd1940 said: My Task manager says CPU utilization is: system idle process 88 and Prime95 12.

2004-07-05, 17:55	#5
TauCeti Mar 2003 Braunschweig, Germany 342₈ Posts	Hmm, strange one. Some ideas: Do you use Windows XP? Does your System idle process (check in task manager) only use a tiny amount of memory (20k on my machine)? Just to make sure it is really the 'normal' idle process and not some disguised malware. You could raise prime95 priority with the advanced/priority command. Try setting it to '9'. You find the password to enable those advanced functions in the readme.txt (section ADVANCED MENU) If you use win XP you can also try to boot in safe mode and check if the situation stays the same. I thought about the possibility that your cooling solution is malfunctionung (can you check the CPU temperature?) but i don't think you would get high idle time that way. but: can you run some benchmark like Sysmark or SiSoft Sandra? Just to make sure your system performs ok in general. Ok, a lot of wild guesses here but maybe a lucky hit... Tau