Why is dual PIII performance so bad?

[jeepman]

I have dual PIII 500 MHz 512KB Katmai's. When running a single WU against both processors, SETISpy says it will take over 15 hours, and it is using 16+ CPU cycles/FLOP!

Man that is horrible performance.

If I run two instances, with the -cpu switch set accordingly, SETISpy says each unit will take over 17 hours each.

Is there any way to tweak this system? I have 128MB PC100 RAM

[Guru]

Check out the link in my signature!
What motherboard are you using what's your memory timings and what OS are you using?

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[jeepman]

I am running NT 4, SP6a.

Memory is autotyped by PhoenixBIOS. I do know it is CAS3 memory.

No way to change memory timings that I know of.

Motherboard is 440BX based Micronics Helios.

[jeepman]

I may try and track down the register used to set CAS in PhoenixBIOS on my motherboard and use WPCREDIT to change the value!

Any ideas?

[Guru]

Have you tried AGP info?(freeware) http://www.tweakfiles.com/video/agpinfo.html

Here is another prog.(shareware) http://www.tweakfiles.com/bios/tweakbios.html


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[Rattledagger]

Does it actually take 17 hours, or is it just the reported time at the beginning of a wu?

Is the cache disabled in the bios? Is each instance of seti@home using 50% cpu? Are other programs using much cpu-power?

Are the cpu's running at 500 MHz or over/underclocked?

Last but not least, that version of seti@home is you using? The correct should be setiathome-2.4.i386-winnt-cmdline.exe

[Guru]

I dont know if this is faster with katmais but I have read that with dual coppermines the fastest setup is GUI 2.70 on one cpu and CLI 2.4 on the other!

Oh btw Rattledagger har du hört om det kommer att komma en 3.0cli?

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[jeepman]

I set the L2 Latency to 4 for each CPU, and the times are reported even higher!

I am relying on SETISpy to give me correct info. It now reports ~25 CPU cycles/FLOP!!!

Should I try a lower latency, like 2?

I have used CPUID and everything looks fine, and I can see the L2 latency is changed.

I am running the latest NT command line client.

Once I get this system figured out, I need to check out why a 600E Cu running the latest everything under Win98 shows that it will take 78 hours according to SETISpy!

[Pace]

So how many WUs is the system crunching in a day?

(btw Jeepman, I'm away for a few days so look for a lack of WUs from me until Tuesday/Wednesday). I'm going to miss our entry into the top 20 producers

Paul.

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[jeepman]

OK, I have found the CAS latency and it is set to 3.

I know I have CAS 2 memory, and I am not OC'ing so I will create an environment that will set it to 2 and see how that helps.

I have set the L2 Cache to 2 on the other system, and I am now down to ~10-12 CPU cycles/FLOP. Should see better times.

Pace, no problem I have brought up a 600E, and 650E, and a PII 400 and they will crunch over the weekend and Monday. Have fun.

[Guru]

I will post some more tweaks for you here later! It's 0315 over here and I'm off to bed!

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[jeepman]

OK, CAS 2 is a no go. NT no boot! Good thing I have FAT16.

Anyways, back to the drawing board. Thanks everyone.

[Rattledagger]

Guru, of course it's coming cli-versions, but not in beta-versions.

Jeepman, I haven't tested setispy, but I've heard the predicted times can change much in the course of work-units, especially at the start. To really know how fast the machine is, you must report the finishing-times.

As for the win98-machine reporting extremely high times, this is because win98 doesn't use cpu-times but run-times. Everything running alongside gives higher results. NT is the same if you're using gui-version. I've used over 100 hours on one wu. Of course, a wrongly configures gui-version can on it own give high results.

BTW, did both instances use 50% cpu in NT?