tech question about cpu failure

[cmc]

Hi Folks

I have a late-90s box I keep up for fun. It is a Dell R450 with a Voodoo 3 and SB Audigy 2.

Recently I have been playing around with upgrading the CPU. I had to find exactly the right slocket adapter, a Gigabyte GA-GR7+. That slocket is one of the few reported to work for the R450. Here's a site that reports success upgrading the R450 (a 440BX chipset) to a Coppermine CPU with this slocket: http://www.roberthancock.com/dell/xpsrproc.htm

The box boots up and works normally in the slocket with a socket 370 Celeron that I have sitting around. That Celeron is slower than the PII 450 that came with the Dell, but it is a good test.

Next, I tried another CPU I got free somewhere, a PIII 650, SL3VJ. The computer boots up fine and is noticeably faster for most tasks. But, DirectX won't run! Any Win98 program using DirectDraw, DirectSound, etc., crashes with various error messages. If I turn off the computer and boot back up with the Celeron or the original PII, everything is fine again. So I have to conclude that the PIII is the issue. As I say, it was a freebee somewhere, so I am not all that surprised it has an issue.

But now I have a technical curiosity question: what kind of failure would cause just DirectX to crash, but leave everything else alone? Why might this happen?



BTW if anyone has a known-working Coppermine socket 370, 100mhz bus, 600-900mhz PIII you want to sell me, send me a PM. I'd like to try out another one.

 

[Agent Orange]

Hi Folks

I have a late-90s box I keep up for fun. It is a Dell R450 with a Voodoo 3 and SB Audigy 2.

Recently I have been playing around with upgrading the CPU. I had to find exactly the right slocket adapter, a Gigabyte GA-GR7+. That slocket is one of the few reported to work for the R450. Here's a site that reports success upgrading the R450 (a 440BX chipset) to a Coppermine CPU with this slocket: http://www.roberthancock.com/dell/xpsrproc.htm

The box boots up and works normally in the slocket with a socket 370 Celeron that I have sitting around. That Celeron is slower than the PII 450 that came with the Dell, but it is a good test.

Next, I tried another CPU I got free somewhere, a PIII 650, SL3VJ. The computer boots up fine and is noticeably faster for most tasks. But, DirectX won't run! Any Win98 program using DirectDraw, DirectSound, etc., crashes with various error messages. If I turn off the computer and boot back up with the Celeron or the original PII, everything is fine again. So I have to conclude that the PIII is the issue. As I say, it was a freebee somewhere, so I am not all that surprised it has an issue.

But now I have a technical curiosity question: what kind of failure would cause just DirectX to crash, but leave everything else alone? Why might this happen?



BTW if anyone has a known-working Coppermine socket 370, 100mhz bus, 600-900mhz PIII you want to sell me, send me a PM. I'd like to try out another one.

Your CPU is probably okay. What I think you need to do is upgrade Windows DirectX to at least 6.1 or the latest version you can find. Check back in if that works.

 

[Scali]

The problem might be that the PIII has SSE, and Windows 98 does not support SSE. DirectX and/or the software you're using may try to use SSE and result in crashing the system.
You could try it with a newer version of Windows (I think Windows 98 SE should do).

 

[Dwight Elvey]

Often processors have a few bad instructions. It is part of the bios function to load patch RAM with corrections. It is possible that you are seeing just such a problem. The bios you have may not have the right patch for the processor you have or it may have an incorrect patch for a different processor.
It is rare that you can swap processors without the proper bios, for all operations. Most things like booting usually work but often there is a design error that gets caught in the field when particular instructions are run in sequence. The processors of today are so complicated that there just isn't enough simulation time to make sure every combination of things work.
Dwight

 

[Agent Orange]

The problem might be that the PIII has SSE, and Windows 98 does not support SSE. DirectX and/or the software you're using may try to use SSE and result in crashing the system.
You could try it with a newer version of Windows (I think Windows 98 SE should do).

Could be all you say. However, I have a PIII Tualatin (1.4 GB) running on an Intel 815 mobo with XP and do not encounter those problems. My PIII is my tweener.

 

[NeXT]

I'm going to say it's an installation issue/version issue with DirectX. A lot of the earlier versions were really buggy. I wouldn't run below version 7 if I had to. Experiment with a clean install.

The problem might be that the PIII has SSE, and Windows 98 does not support SSE. DirectX and/or the software you're using may try to use SSE and result in crashing the system.

98's lack of SSE support should prevent DirectX from trying to access the instructions.

 

[Scali]

98's lack of SSE support should prevent DirectX from trying to access the instructions.

But it cannot prevent poorly written software from accessing SSE instructions. A lot of software will try to use CPUID to determine SSE support (or worse: check that it is a PIII CPU and assume SSE will be available), rather than using the proper Windows APIs to see if the feature is actually enabled by the OS. In which case, things crash.
I think either way you shouldn't run an OS that isn't capable of SSE on a PIII.

 

[cmc]

Thanks for the answers! I had not considered any of the ideas mentioned here, though I can provide a little context. I am running Win98 SE with the "unofficial service pack" 3.57 that has been floating around a few years. It includes DirectX 9. I didn't think about whether software versions support SSE or not, though perhaps it is some combination of SSE and the bios not being designed for this CPU. What I really need to do is 1) find a working PIII system and plug in my CPU to see if I can replicate the error on a different computer, and 2) get another Coppermine PIII and test it in my machine.

If I determine that the CPU is not the problem, then perhaps the issue is in something that the unofficial service pack installed. I know it has a custom DirectX of some kind. Also, all the discussion I found of using a Coppermine CPU in the Dell R450 (via the slocket) mentioned Windows XP, not 9x. I don't recall anyone ever saying that 9x didn't work, but the context of the upgrade was always XP. So perhaps I could stick and XP drive in there and see if it works. So much testing to do...

 

[cmc]

Hi Folks

Did a bit more testing. I was able to find a Coppermine Celeron and to boot Windows XP on a different drive. It was a little hacky, but it worked.

WORKS
Win98SE + DX9 + Pentium II
WinXP + DX9 + Pentium II / III / Coppermine-Celeron

DOESN'T WORK
Win98SE + DX9 + Pentium III / Coppermine-Celeron

So I know the PIII is OK. The slocket is OK. The mainboard is OK. Seems to be something with SSE and Win98SE and DX9?

 

[Agent Orange]

Hi Folks

Did a bit more testing. I was able to find a Coppermine Celeron and to boot Windows XP on a different drive. It was a little hacky, but it worked.

WORKS
Win98SE + DX9 + Pentium II
WinXP + DX9 + Pentium II / III / Coppermine-Celeron

DOESN'T WORK
Win98SE + DX9 + Pentium III / Coppermine-Celeron

So I know the PIII is OK. The slocket is OK. The mainboard is OK. Seems to be something with SSE and Win98SE and DX9?

Just a long shot at this time, but see if there is a BIOS upgrade available for the mobo.

 

[Scali]

Seems to be something with SSE and Win98SE and DX9?

Could be. DirectX 6.1 first introduced SSE support. Windows 98 SE ships with 6.1 by default.
Perhaps your unofficially patched version doesn't work properly.
I'm pretty sure Win98SE works fine with DX9 on an SSE machine if installed properly, because I believe I used it on my Athlon XP for some time.

I'd try a clean install of Windows 98 SE, first verify that it works with DirectX 6.1 (you could use Final Reality and 3DMark99 MAX as good test cases for early DirectX stuff).
If that works properly (which it should), then I'd install the official DirectX 9 redistributable, and see if that works (which it should).

 

[cmc]

I do have the latest BIOS, though some reading suggests it might actually be better to downgrade a couple versions due to some "feature" Dell added in the later ones that can cause problems.

Very interesting, I found this: http://www.roberthancock.com/dell/benchmy.htm

Those are benchmarks for someone who took basically the exact same steps as me, and was using Windows 98. Apparently it worked fine. The only difference that I can tell is that he used an IWill Slocket versus the Gigabyte one I used.

 

[Scali]

If the machine works correctly in XP, then I think we can assume the BIOS is not an issue. The point raised earlier was that BIOSes usually contain microcode updates for the CPU to fix small bugs. Since you are using a motherboard/BIOS that was never designed to run a PIII, it's highly unlikely that it contains microcode updates for the PIII.
But if XP runs on it without issue, then the microcode is probably fine.
Having said that, the OS may also contain microcode updates, so it could be that XP fixes something that the BIOS did not. However, in that case, Windows 98SE should also have a fix for that. But I do not recall any major issues with the PIII requiring a microcode update in those days.
Also, since the issues you have are very specifically with DirectX-software, and the rest of the system works fine in Windows 98SE, I suspect it is related to DirectX/SSE.