can anyone advise on PSU requirements?

[iwasinnamuknow]

Hi all,

I've just upgraded my machine to:

* Phenom 1100T
* Crossfire Formula IV
* 16gb Corsair Vengeance DDR3
* 2x HD6950 in Xfire

I used my existing Antec 600w PSU and had to use 3 of the provided adapters to supply the 4 power connectors on the graphics cards.

I've been having one or two small issues, apparently relating to graphics. Is this power related? I can remember my ohms law etc well enough to work out if I need a bigger PSU.

I don't want to go and blow another £100 on something that won't fix the problem.

Any advice would be appreciated.

Thanks

 

[Tealc]

The 6950 are 200w or thereabouts cards so by the time you power them you aren't leaving much headroom.

Maybe invest in a killowatt meter to be certain.

 

[cmndr_andi]

Hi there, welcome to the forums

Looking at this PSU calcualtor, using a 600W PSU is running pretty close to the edge with this setup. May I ask what model antec 600W you are running?

I would suggest upgrading to a good quality 750W if you have the money as this will give you more headroom for overclocking and upgrade- plus it certainly won't be running close to the red-line when running your system at full-load.

Also you should get a fair bit back by selling your 600W Antec - they make good PSUs.

 

[iwasinnamuknow]

Thanks for the replies guys,

I wasn't sure how close it would be, as most of the number i could find are maximum ratings...which i guess really i should allow for anyway.

I think i'll have to upgrade, and probably will go >750w just to be future proof. I'm not sure what the current one is. I've only just put it back together from the upgrade and don't fancy getting it out again yet

I'll probably end up going for a 1kw, are there any that come with lots of the PCIe 6-pin connectors for the 6950s? Feels wrong to get a spanking new PSU and then use the adapters again.

It says in the quick start guide that I shouldn't use the adapters, but then it gives me 2 in each box

Thanks again for the quick advice, I'll see if I can sell this one and get something a little beefier.

 

[cmndr_andi]

The 1kW PSUs are nice, but they are mad expensive and unless you plan on adding two more 6950s then will generally be wasted. Instead, going for a cheaper, more efficient 750W PSU like this would be my recommendation. It comes with four 6+2 pin PCIE power connections - so exactly what you are needing.

 

[iwasinnamuknow]

Yea i've just been looking at the PSUs and the calculator...I think you might be right, that one you linked does look like it'll do the job. I just hope that this fixes my problems.

The main problem was that under heavy load on all components (6 cores + 2 GPUs), the fans all went crazy then the machine bluescreened.

I was initally sceptical about the PSU so I wasn't too suprised when it all went **** up. I just hope thats the only reason

 

[Tealc]

GPU fans ramping to 100% is indicative of a power issue. I get the same effect when I remove one or both pci-e power connectors. When I do get a gpu crash it tends to only ramp fan on reboot though.