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Old 2006-08-17, 15:11   #1
Clyde83
 
Aug 2006

11 Posts
Question Pentium4 2.8Ghz speed help needed

Help,
I have a Pentium4 2.80GHz L2=512 and only Norton running in backgroud I still get Interation times almost exactly 1/2 speed of what benchmark page says it should be. Prime95 is running 99% when viewed with task manager and taskmanager takes up the other 1%. Everything else is 0%.

Is the benchmark page possibly inaccurate, I understand the numbers maynot be exact but the figures for my machine per interation on a 35M size exponent doing LL test is 0.152sec. I checked the benchmark page and it indictates a Pentium4 at 1.4GHz speed same L2 of 512.

Is there some test to run to check system speed?

Any help in this would be greatly appreciated!

Clyde83
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Old 2006-08-17, 16:07   #2
TauCeti
 
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Quote:
Originally Posted by Clyde83 View Post
Help,
Is the benchmark page possibly inaccurate, I understand the numbers maynot be exact but the figures for my machine per interation on a 35M size exponent doing LL test is 0.152sec. I checked the benchmark page and it indictates a Pentium4 at 1.4GHz speed same L2 of 512.
Clyde83
Did i understand you accurately? Your speed ist about 0.152s and according to the benchmark page should be about 0.07s?

Did you use the benchmark command (options/benchmark) to determine your numbers?

For my system here i get:

Intel(R) Pentium(R) 4 CPU 2.60GHz
CPU speed: 2636.85 MHz
CPU features: RDTSC, CMOV, Prefetch, MMX, SSE, SSE2
L1 cache size: 8 KB
L2 cache size: 512 KB
L1 cache line size: 64 bytes
L2 cache line size: 128 bytes
TLBS: 64
Prime95 32-bit version 24.14, RdtscTiming=1
[...]
Best time for 1280K FFT length: 43.285 ms.
Best time for 1536K FFT length: 53.442 ms.
Best time for 1792K FFT length: 63.224 ms.
Best time for 2048K FFT length: 70.671 ms.
Best time for 2560K FFT length: 92.259 ms.
[...]

so - yes - 0.152 for 2048K FFT seems too slow.

is it possible that your system has a thermal problem, e.g. broken CPU-Fan, Dust? In that case it could be possible that the CPU throttles to avoid damage due to overheeating.

There is a tool "throttlewatch" (search google) to determine if that is the case but i have never used it myself so far.

I don't think that memory timings/bandwidth could be the problem - your numbers are too far off.

Tau
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Old 2006-08-17, 19:49   #3
Clyde83
 
Aug 2006

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Default Speed Problem

I have not checked the cooling but will do that tonight with temp tools, all fans work ok, case is always off and I run it 24/7 in my cool basement.
It has run like this I believe since I started with GIMPS last Jan. but just lately I looked at the benchmark page to see what it should run at.

How did you find all the L1, L2, and others on your computer? I can't find any of mine had to go to Intel site to find L2 info for my speed processor.
No other info found, no sticker, paperwork with that data or spec sheet came with my system when I bought it new. Also looked in BIOS and no info other than 2.804Ghz listed even under "Advance" area of BIOS.

I'm assuming INTEL is correct about the L2 memory being 512k, my system RAM is 512Meg and I have no other programs running or installed except latest version of Prime95 and XP Home SP2

I will look into speed program that you mentioned.
I keep a log of speed per second of Interations and all of them indicate 2 times what benchmark data says it should be.

Thanks
Clyde83
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Old 2006-08-17, 20:07   #4
paulunderwood
 
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Quote:
Did you use the benchmark command (options/benchmark) to determine your numbers?


It's part of prime95.

What is the memory usage settings are in prime95?

Last fiddled with by paulunderwood on 2006-08-17 at 20:11
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Old 2006-08-17, 22:41   #5
Clyde83
 
Aug 2006

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Default System Not Overheating!

Good news atleast the CPU isn't overheating runing between 79F-87F (depends on location of temp probe on CPU)

I have available RAM for Prime95 set at 256M
According to Prime95 stats:
CPU Speed=2804.6 MHz
CPU:rdtsc,cmov,prefetch,mmx,sse,sse2
L1=8KB
L2=512KB

I'm going to try some speed test software next.
I found that if I change XP settings for monitor resolution to 16bit vs 32bit I get an additional 0.016 speed increase now at 0.136 for a 35.4M Exponent.

I have a feeling (great technical observation) that my system is working fine just the level of processing is intense, I noticed that the bigger the exponent the longer per interation it takes.

Any suggestions would be helpful will consider any/all.

Clyde83
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Old 2006-08-17, 23:09   #6
PhilF
 
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I assume your temperature reading of 79-87F is at various places on the heat sink, not on the CPU itself. If so, that doesn't really tell you much, because there could be a problem with the heat sink not being in good contact with the CPU. That would explain a fairly cool heat sink, and also a CPU that is so hot it is throttling. Throttling is about the only thing I can think of that would cause your speed to be as slow as it is.

If you have a software temperature monitoring utility I would use it to check the CPU's temperature instead of a hardware probe.
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Old 2006-08-18, 00:03   #7
Prime95
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Quote:
Originally Posted by Clyde83 View Post
I found that if I change XP settings for monitor resolution to 16bit vs 32bit I get an additional 0.016 speed increase now at 0.136 for a 35.4M Exponent.
Do you have some kind of horrible on-board graphics chip that is competing with prime95 for memoryt bandwidth?

Quote:
I have a feeling (great technical observation) that my system is working fine
I don't. I could dismiss a 10% variation, but your variance is way too large.
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Old 2006-08-18, 09:57   #8
TauCeti
 
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Quote:
Originally Posted by Prime95 View Post
Do you have some kind of horrible on-board graphics chip that is competing with prime95 for memoryt bandwidth?
I also thought of that possibility. However, some month ago i had an argument with a fellow cruncher about the effects of on-board graphics (he thought there was none). I did some tests at that time:

FSC Business PC/Athlon 64 with SiS chipset:

800*600/16/60Hz : 2132 MB/s Mem bandwidth, Best time for 4096K FFT length: 260.250 ms.

1600*1200/32/60Hz : 1661 MB/s Mem bandwidth left, Best time for 4096K FFT length: 272.927 ms

Even using a old P-III with Intel 815 integrated graphics i got a maximum increase of about 10% using the highest possible screen resolution/freq.

Clyde86: How about using the SiSoft Testsuite (http://www.sisoftware.net/) to determine the memory bandwidth for your system? The Testsuite also includes some other benchmarks we could use to compare your system to the 'norm'

One other idea: Start your computer, start prime95 but use the stop command in prime95 to stop it (prime95 icon changes from red to yellow). Wait 5 Minutes and then start the benchmark included with prime95 (options/benchmark) and post your results. If you have a throttle/temp problem it is possible that the cpu works for some seconds at full speed and then throttles. We should be able to observe such behaviour analysing your benchmark results.

EDIT:

I - err - just noticed that Clyde got a 8,5% boost changing from 32 to 16bit colordepth. That's a huge boost! What brand is your computer (Dell, homemade, HP...)? You could also set your screen resulution to the minimum possible (e.g. 800*600/16 bit) and then to the maximum resolution your monitor supports with 32 bit and post the iteration times for both settings.

Tau

Last fiddled with by TauCeti on 2006-08-18 at 10:26 Reason: Did not read all posts carefully before i posted
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Old 2006-08-18, 13:47   #9
Clyde83
 
Aug 2006

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Default Speed Problem persists?

You guys are great! Thanks for all the fast replies.
I d/l'd "Throttle Watch" and ran it heres the results w/Prime95 running & w/out.

W/Prime95
CPU usage:100%
Throttling:0%
CPU Freq. 2805.0MHz

W/out Prime
CPU Usage:0-1%
Throttling:0%
CPU Freq: 2805.0MHz

Checked CPU temp at CPU below heat sink w/probe & laser temp sensor max heat w/Prime @ 100% did not exceed 96F

I have never gotten any errors and have used this machine as is for almost 2 years now last 8 month w/prime.

I have the screen resolution and also all windows settings for fastest system use with no bells and wistles.
System is an Clone from CompUSA & have the main RAM for Prime set at 256M. What is best memory setting to use?

I mentioned in last post or so that I keep my system in my basement which is about 5-10 degrees F. cooler than the rest of my house. FYI

I will check on the other software tonight you mentioned to test it with.

Clyde83
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Old 2006-08-18, 15:40   #10
Prime95
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So it isn't a heat or throttling problem.

My money is on on-board graphics. Do you have access to a cheap graphics card? They can be had for as little as $5. Heck, you probably know someone with an old one lying around unused. You'll need dto figure out if you need a PCI or AGP card by looking at your computer documentation or examining the motherboard.
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Old 2006-08-18, 16:09   #11
dsouza123
 
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Sep 2002

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Other ideas, though less likely.

Rootkit using up CPU time and memory bandwidth.
(Some games and audio CDs install them.)
WinModem using up CPU time.
RAM not set at the correct speed, or mixed speed grades of RAM.

Another testing scenario.
Testing in Windows Safe Mode.
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