PSU voltage rails

[Hawke84]

Hi.
I have a hyper 880w psu
http://prices.kitguru.net/productinfo/2524/hiper-hpu-4m880/specifications

The specs say I have several 12V rails with different amp ratings.

I'm looking to upgrade to a GTX980ti which says 42A requirement. Is my psu ok because the load is spread across two rails?

How do I tell which rails the pci-E uses?

Want to make sure I don't overload my trusty psu!

Thanks

 

[GotNoRice]

It looks like you have a 6 pin and an 8-pin coming from each of your 3rd and 4th rails. Each rail is good for 30 amps. Yeah, you can spread the load across multiple rails without issue. You should be fine.

 

[Hawke84]

Cool thought so thank you. For my learning how do I know the pcie isn't from 1st and 2nd rail?

 

[lehtv]

http://prices.kitguru.net/productinfo/2524/hiper-hpu-4m880/specifications

These specs are incorrect. The total +12V capacity is not 96A, that's just a sum of the different +12V rails.

Here are the actual specs from JonnyGuru's review:

The 42A requirement of your graphics card refers to the power supply's total +12V capacity which in your case is 768W (divide by 12V, you get 64A). It does not mean the graphics card itself will use 42A - that would be ludicrous because 42A is equal to 504W of +12V power, while GTX 980 Ti uses about half that. So with 64A on the +12V you're more than covered

For my learning how do I know the pcie isn't from 1st and 2nd rail?

My educated guess would be that rails 3 and 4 are responsible for the four PCIe connectors. High end graphics cards tend to use much more power than processors and other +12V devices, so it makes sense to assign the most powerful +12V rails for PCIe connectors.

 

[Hawke84]

Thank you very much this helps a lot and saves me a fair amount of money. So you know how I can test if psu is struggling or is it just plug in and stress test and see if it cuts out?

 

[lehtv]

Well first off, don't worry about it, the unit is more than adequate and there is no need to prove it is by testing. If you experience PSU related symptoms like random shut downs or restarts, then the unit is faulty rather than simply inadequate for the 980 Ti.

However you can buy a power meter or kill-a-watt and find out precisely how much power the PC draws. With 980 Ti and an otherwise normal system, you should be using about 350-400W from the wall while gaming.

 

[Hawke84]

Ok 1 more question - pushing my luck with this... is using an additional GTX680 for physix gonna be too much?

 

[lehtv]

People still run dedicated physx cards?

It should work fine. But I'm not convinced you'll get much better performance compared to running physx off of the 980 ti. Better to just sell the 680

 

[Hawke84]

Yeah researching it seems to be a waste of time having a dedicated card. I just don't like paying a fortune for it and now it's worth next to nothing!

Thanks again for the help. System. Nice and stable