Is my PSU running out of juice or something?

[Marty502]

As you can see in my signature, I have something you could call mostly a 'frugal' rig (besides the x1950 Pro) and a ThermalTake TR2 PSU, which delivers 430 watts.

But I just noticed something odd, and annoying, and I don't know if it's related to my PSU, my motherboard, or else, and I think it might be what's frustrated any serious attempts to overclock my computer for a long time:

My vcore raises 0.5V under CPU load.

You might think, what's wrong with that? Actually, a lot.

You see, if I put my CPU at 2.7 Ghz, it needs 1.5v to boot up. But at Windows, under heavy load, it rockets to 1.55v, which is overkill. And if I put it lower, say... 1.475v, then it won't always boot up to Windows. But if it does, it runs Prime95 just fine. That's with 1.525v under load. And it's really annoying. Why does that 'voltage throttling' happen?

I've managed to override this issue a bit by using Clockgen, and raising the FSB in Windows. But still... it's the sort of thing that just shouldn't be. Is this because my PSU is just wimpy? I know nothing about electronics or electricity or whatever, but I've this PSU is kinda weak on the amp values, at least on the 12V rail... whatever that means. Might that be it?

Thanks in advance.

 

[Yellowbeard]

The guys at the old DFI Street forum, now the DIY forum used to STRONGLY warn against using a lower power output PSU on those boards. You may want to prowl around there or just try a higher quality high amperage PSU.

 

[Marty502]

I didn't know that. I'll check that forum man. Thanks a lot.

 

[Yellowbeard]

Originally posted by: Marty502
I didn't know that. I'll check that forum man. Thanks a lot.

Ooops, sorry, the coffee has not kicked in and I forgot to provide a link. Apparently, those DFI boards were very picky and demanding on PSUs.

http://www.diy-street.com/forum/index.php

 

[Marty502]

Nevermind, I used to stalk on that forum.

And yes, they say that for stability reasons you have to have at least a 480 Watts PSU. Guess that explains all the issues I've had these years...

You already know what I'm gonna buy next month.

Thanks a lot!

 

[SparkyJJO]

What are you using to check your vcore? Software? If so, dont trust it, according to software mine was bouncing around but I used a DMM and it is steady in reality.

 

[Marty502]

That's a good question.

I have this: Speedfan shows the 0.5v increase when I do Prime95. But let's say I put my vcore at 1.45v in the BIOS... if I reboot and check, the option is 1.45v but the "CPU voltage" tab shows 1.5v too.

So, in your case it actually stood where you set it?

EDIT: Cpu-Z shows only a 0.25v increase... *wink wink*

 

[Marty502]

Just wanted to update you on this subject, people.

Got a CoolerMaster eXtreme 600 Watts PSU. Not too highly regarded I think, kinda noisy, but it's all I could afford.

Still the voltage oscillation is there according to software, but who cares? I can now crank 2.7 Ghz on my CPU with stock vcore! Temp on load dropped to 49ºC after 30 minutes of two Prime95 instances. It used to be around 58ºC, which was awful and disappointing and crap overall.

I miss how silent the ThermalTake TR2 was.

 

[mpilchfamily]

The problem is you are relying on a software voltage reading which isn't exactly right to begin with. Unfortunatly unless you know what you are doing you won't be able to check the Vcore with a DMM.

 

[Marty502]

Yeah, I know. Annoying, but what the hell. Not that I need to know it now that my PC boots without a problem, every single time...