Downgrading from HT processor to non-HT

[ChertseyAl]

Long story cut short ... :help:

I had a spare P4 HT processor, so I tried it in an old XP PC that had a non-HT Celeron-D in it. Unfortunately, it was a disaster. PC ran very slow. Put the old processor back in.

Mostly it runs OK, but about once a day it runs so slow that a ten minute Primegrid task takes 7 hours. Rebooting brings it back to normal for another day.

I *think* that the problem is the HAL was replaced with the multiprocessor one. And there's no 'downgrade' path :(

I've replaced the RAM, the PSU, the processor cooling fan etc (I had spares luckily!) but nothing fixes it. Oh, there are no useful restore points for some reason :scratch:

The obvious thing is to reinstall XP or install Ubuntu. But the CD drive doesn't work, it has no kbd/monitor/mouse (VNC only) and as this was a $30 throwaway PC I'm not going to spend any money on it ;)

Oh, I'm OK with upgrading hardware. Done loads of processor and memory upgrades without problems, regularly fix my clunky Dells (PSUs and fans) etc so I don't think it's a hardware problem.


Ideas anyone?

Al.

[Bok]

Likely just some windows drivers. You could uninstall the mobo drivers and get them to re-install automatically perhaps. Though I'd just find a way to re-install, perhaps via a USB drive?

[Bigred]

Long story cut short ... :help:

I had a spare P4 HT processor, so I tried it in an old XP PC that had a non-HT Celeron-D in it. Unfortunately, it was a disaster. PC ran very slow. Put the old processor back in.

Mostly it runs OK, but about once a day it runs so slow that a ten minute Primegrid task takes 7 hours. Rebooting brings it back to normal for another day.

I *think* that the problem is the HAL was replaced with the multiprocessor one. And there's no 'downgrade' path :(

I've replaced the RAM, the PSU, the processor cooling fan etc (I had spares luckily!) but nothing fixes it. Oh, there are no useful restore points for some reason :scratch:

The obvious thing is to reinstall XP or install Ubuntu. But the CD drive doesn't work, it has no kbd/monitor/mouse (VNC only) and as this was a $30 throwaway PC I'm not going to spend any money on it ;)

Oh, I'm OK with upgrading hardware. Done loads of processor and memory upgrades without problems, regularly fix my clunky Dells (PSUs and fans) etc so I don't think it's a hardware problem.


Ideas anyone?

Al.

Put the P4 back in and go into the BIOS and disable the HT. It never has worked correctly with Boinc. I would also do a fresh install of the OS. Have you tried Dotsch (http://www.dotsch.de/boinc/Dotsch_UX.html)? It will even run from a memory stick.

[ChertseyAl]

Put the P4 back in and go into the BIOS and disable the HT. It never has worked correctly with Boinc. I would also do a fresh install of the OS. Have you tried Dotsch (http://www.dotsch.de/boinc/Dotsch_UX.html)? It will even run from a memory stick.

I *think* I already disabled HT in the BIOS. Worth checking though *adds to list* :)

Dotsch is a good idea. I'd already bookmarked the download page a while ago *adds to list* :)

FWIW, I did find a way to change the HAL. Doesn't seem to have made any difference - Had a runaway PG task last night :bang:

The thing is, I can bring the machine into my den, connect up a spare K, V and M, replace the CD drive, fiddle with the BIOS, install an OS ... Or I can take out the DIMMs and maybe PSU and dump the carcase in the trash. Given the lousy RAC on most projects, it's the best thing to do :trash: ;)

But, I like to get to the bottom of things, so I think I'll persevere. Even though those DIMMs would be very handy for another machine ... :jester:

Al.

[Bigred]

Any chance it has a PCIe slot? If so with an ATI 5850 on Milkyway it would earn over 100,000 credits a day.:idea:

Leave the CPU idle and just run the GPU. I've got a P4 with a 4850 (http://milkyway.cs.rpi.edu/milkyway/show_host_detail.php?hostid=23229) cranking out almost 60,000 a day which isn't too bad for an old machine.:cool:

[ChertseyAl]

Any chance it has a PCIe slot? If so with an ATI 5850 on Milkyway it would earn over 100,000 credits a day.:idea:


Great idea :) But it appears that it doesn't :(

I'm going to have to check the BIOS and while I'm at it I'll drop in a spare CD drive. I could put XP back on, but don't fancy faffing about getting drivers. So I suspect I'll just put Ubuntu on if I don't get around to trying Dotsch before then.

Al.

[Bigred]

Great idea :) But it appears that it doesn't :(

I'm going to have to check the BIOS and while I'm at it I'll drop in a spare CD drive. I could put XP back on, but don't fancy faffing about getting drivers. So I suspect I'll just put Ubuntu on if I don't get around to trying Dotsch before then.

Al.

If its got AGP you could put a 3850 in it if you can find one. Not sure about the credit but it has to be better than what the CPU would earn.

[ChertseyAl]

If its got AGP you could put a 3850 in it if you can find one

Interesting! Yes, it has AGP. Might be able pick one up, but the price is looking prohibitive - Remember this is a $30 PC :harhar:

But, it appears I've found something strange with the machine that I hadn't noticed before. I'm thinking the HT thing might be a red herring. It had a really nasty crash just before I was fooling with the processor and some XP settings got changed, as if a bunch of default settings got reloaded :scratch:

Years ago I was experimenting with XP settings, and this PC had been left in 'best performance' "visual effects" mode (looks like W2k). Realised yesterday that it had gone back to standard (TellyTubby) some time ago. So I put it back to 'best performance'. Since then it's been running fine. Famous last words I expect. Can't think why it would make a difference :confused:

FWIW, the difference in RAC between 'best appearance' and 'best performance' was about 1% across the projects I benchmarked at the time!

Al.

[outlnder]

If it starts running poorly again, check to see if the processor is throttling down due to overheating. And make sure BIOS settings has throttling turned off.

[ChertseyAl]

If it starts running poorly again, check to see if the processor is throttling down due to overheating. And make sure BIOS settings has throttling turned off.

Latest gripping news update! ;)

Still wasn't 100% reliable. Connected up a kbd and monitor and took a look in the BIOS. Nothing wrong. But I did up the fan ratio and base/minimum speed as I don't care about fan noise for this machine. That knocked 15 degrees off of the CPU temperature (which was within limits anyway). No sign of throttling before (used a couple of the 'standard' throttle monitors and they never recorded any throttling, even when the machine was running slow).

So, as I had a use for the DIMMs, I whipped them out and dropped in a single 'big' DIMM. And, so far, so good. I'm wondering if it's a dodgy DIMM socket, as it ran fine with the original single DIMM, and it's only really since I've been swapping memory around and adding memory that the problem surfaced.

I'll be back next month to tell you that the latest 'fix' made no difference :rotfl:

Al.

[ChertseyAl]

Hehe. Necroposting, but just found this thread again and thought I'd post the answer for my own benefit ...

Turns out the mobo is *very* fussy about DIMMs. Really fussy. Managed to get the machine stable with a single 512 DIMM in slot 0. Pretty much anything else doesn't work. To be fair, the mobo manual only recommends DIMMs that I either don't have or can't get.

Cheap PC -> Months of pain :( But, cheap is cheap, and I got there in the end :)

Al.