Why won't my 745 Ultra play nicely?

[Wombat]

Okay guys, I'm a little stumped as to what's going on with this box. I've got a revB in my 745 Ultra, but something's not adding up.

The L3s are uncut, so the highest mult I have is 12.5.

With the FSB/RAM at 133/133, the box is perfectly fine.
At 166/166, the box boots happily, and runs pretty well, but locks up as game engines get going - it appears to lock up doing DMA transfers with the Audigy (I always get a whine out of the speakers when this lockup happens). I've tried all sorts of multipliers here, as well as RAM voltage and CPU voltage (limited to 1.7V though).

At 166/133, the machine will not boot! It doesn't POST, and when it recovers, it says there is a frequency error.

At 133/166, the machine seems perfectly happy.

I've already cleared the motherboard memory, and reflashed the BIOS.

I don't have the resources here to test all my theories, so any insight or educated guesses are welcome.

[UtwigMU]

Well what are your temperatures?

Observations would indicate CPU seems to be the problem. In that case try investing in better cooling and consider slightly raising the voltage.

[Wombat]

1) I can't raise the voltage.
2) CPU temps are fine, around 50C. Keeping the processor busy doesn't seem to crash it (prime95 for a while).


Also, if it's the CPU, then why will the system lock up at say, 6x166, when it runs perfectly at 12x133? Having a FSB-limited CPU would be very rare.

[Technoid]

try setting PCI latency in bios to 32,
and play around with the other PCI settings....

[omegaRED]

Have you tried it without the audigy?

I know, being limited to 1.7vcore sucks, esp. when the CPU is clearly capable of more.

Well, i`ve just checked the MSI site. It seems that 333MHz FSB CPU`s are NOT supported by the 745 Ultra.

Product info

Supported CPU table

Seems that you`re out of luck

[Wombat]

Technically, they're not supported, but other people have had 166MHz just fine, and I think Greebe was running his at 187MHz for a little while.

If they didn't support 166MHz FSB, then why is it in the BIOS, and why does it have a 5:4 divider (the only possible use for such a divider?). Grrr, I'd have so much more information if that divider would POST.

[Gurm]

Ahem.

Which BIOS revision? The 745 Ultra has had some VERY bizarre BIOS issues.

- Gurm

[Wombat]

I'm using the 1.6 BIOS. The last one I used before that is 1.3.

[omegaRED]

Ummm... k, what are your AGP and PCI bus frequencies? Are they normal or out of spec? The 5:4 divider is for the RAM right? It could be that the chipset doesnt have the 5:1 divider for AGP/PCI, so your PCI/AGP cards are running too much out of spec...

I dont know, i`m just guessing Anyways, check the freqs...

[GNEP]

Wombat: just had a little play around and I have exactly the same issues when trying a 166 FSB. Stable with CPU-heavy tasks (eg climate prediction which will usually catch any instability on by crashing out) - it just seems like games are crashing. AGP/PCI frequencies are fine according to the BIOS as the extra divider just kicks in at 166.

I am using 1.6 and haven't tried 1.7 yet.

The mem is Crucial 2700 so should be fine. The CPU is now watercooled and so temps simply aren't an issue. Just wierd really. Was stable for hours at 100% CPU and doing various bits and bobs (Excel, Moz etc) then I can play JK:JA for about 5 minutes before it bombs out.

Not much I can think of but at least you're not alone...

[Wombat]

Yeah, I was hoping 1.7 would fix this, but it hasn't. It's certainly erratic behavior though.

If I run out of important things to do, maybe I'll try pulling the Audigy out and seeing what happens.

5 minutes is kind of impressive though. I'm seeing the lockups in like 15 seconds.

[Marshmallowman]

can you adjust the bridges on the CPU directly to get extra voltage? you should be able to set at 1.75 maybe even 1.85 via the bridges?

[Wombat]

I don't want to tinker with the voltage. And honestly, I think it's HIGHLY unlikely that it is the source of my problem.

[Guru]

Having the same problem at home! BIOS VER 1.7! XP2200+ Temps ~40 using a fsb of 150MHz!

[GNEP]

I have an Audigy as well. So perhaps that is the problem? Playing MP3s seemed fine though - just gaming... if anyone finds a solution, let us know!