Can't overclock CPU since having 8800GTX!

[XxDeadlyxX]

With my 8800GTS I can change the CPU Host Control no problem. However since I have inserted my new 8800GTX, if I set the Host Control to Enabled, the computer will shut down and restart itself during the POST screen and the setting will be changed back to Disabled. This is reardless of the actual number I set it too, even default 266 etc or even lower numbers like 200 making the CPU frequency 1.8GHz.

Is this because the 8800GTX is draining too much power from my Antec NeoHE 550W? That's the only thing I can think of. The computer at default 2.4GHZ with Host Control disabled is fully stable though, so if it was a power supply thing you'd think other things would go wrong.

When I change from the GTX back to the GTS it is all fine again...

I've tried resetting the BIOS, still the same... also changing voltages and CPU Vcore has no effect.

Any suggestions?

[XxDeadlyxX]

Just found out same thing happens if I change the PCI Express frequency , I used to put it to 102. If I put it to 100 now or 102, it will reboot during POST and reset to disabled.

Helpp!!

[Tr1cK]

How big is the PSU?

Have you tried overclocking the CPU but not all the way to 3.0?

[XxDeadlyxX]

It's this one:

http://fastlanehw.com/reviews.php?i=172

Problem is, when I have the GTX in I can't overclock OR underclock. The only way to get it to POST is set the CPU Host Control (FSB) to Disabled so it's running at 2.4ghz stock.

[Revs]

U tried a BIOS reset?

[XxDeadlyxX]

When I got the mobo it was running BIOS F7 I think, I updated it to F12 when I got it. I just tried putting it to F8, still the same. I'll try F7 now.

Does anyone think my PSU is insufficient? With Q6600 + 8800GTX + 4GB + 3 hard drives, is that pushing it too much causing this problem? Putting the GTS back in fixes it.

[XxDeadlyxX]

Ok changing Mobo bios to F6 did nothing.

I disconnected two HDDs and my Blu-ray internal drive and now it works! My power supply just must not be powerful enough to run everything in my machine along with the GTX. Still, seems so weird the computer worked fine when CPU Host Control was Disabled with everything connected... Hmmmm..

[Prod]

Not sure what to tell you man but a 550W PSU for everything you are running does seem to but abit low. You always want to have alittle extra so you are stressing you PSU all the time. You are sure stressing yours with everything you got running on it.

[XxDeadlyxX]

Oh great..

I started to overclock again just now (it will work with 1 HDD disconnected). Since I bought my new Thermalright Ultra 120 extreme, temps have been about 15c lower than when I had my Zalman 9500. So I set the CPU to 3.15GHz and 1.35V. I do 4xPrime95 as usual, and the comp freezes like it sometimes does if not stable...

But now it won't boot at all. Everything powers up but no POST beep. Taking battery out for 5 mins doesn't help nor does using the CMOS jumper. Have I fried my CPU?

1.35V hardly seems like enough to cause it to just die.. also temps while it WAS doing prime95 for about 30 seconds were still far lower than when I had my Zalman 9500.

[Revs]

When I said try a BIOS reset I meant using the jumper/button on the mobo. You done that?

[XxDeadlyxX]

Yes I did do that. Not that it matters though now that the comp won't post at all... I have left the battery out for an hour and done multiple jumper attempts... no luck. More info in my topic in General Hardware.

[Slammin]

You posted double, but now that I see this one I am sure your PSU is gone.

You overtaxed it and now it goes into an overcurrent condition at power up.

Antec PSU's suck anyway.