5970 usage % issues

[yochdog]

Yeah that is weird.

That PSU is horrible though.  It is "ugly" because it only has 750W but it has that broken into 4 different 12V rails.  Each rail only has 20A. =240W which is right at what a 5970 needs.  It could be starved for power.  Have you underclocked the memory (at least down to 300) that will reduce wattage somewhat?

http://www.rosewill.com/products/698/productDetail.htm

The only other thing to try is use 1 power cable for each rail.  That way 2 rails are powering the same card.  Finding out which cable is on which rail for a PSU like that is tough so you can just try to change the plugs around.  Generally for a 5970 a PSU which either has 1 massive 12V or a few large rails makes power management easier.

SO when I go to buy additional PSU's for expansion and replacement, should I be shooting for single 12V rails with 50A+?  Or should I go for 2 rails with 25A each? 

<3 single rail.

Since you don't seem to be worried by power usage, 80Plus Gold might not appeal to you, but they are well built in any case. Weigh the costs out.

I am tired and not good with lingo.....are you saying less than 3 rails?  or are you "hearting" a single rail? 

Regardless, thank you for the help. 

[1715189880]

1715189880

[rjk]

Yeah that is weird.

That PSU is horrible though.  It is "ugly" because it only has 750W but it has that broken into 4 different 12V rails.  Each rail only has 20A. =240W which is right at what a 5970 needs.  It could be starved for power.  Have you underclocked the memory (at least down to 300) that will reduce wattage somewhat?

http://www.rosewill.com/products/698/productDetail.htm

The only other thing to try is use 1 power cable for each rail.  That way 2 rails are powering the same card.  Finding out which cable is on which rail for a PSU like that is tough so you can just try to change the plugs around.  Generally for a 5970 a PSU which either has 1 massive 12V or a few large rails makes power management easier.

SO when I go to buy additional PSU's for expansion and replacement, should I be shooting for single 12V rails with 50A+?  Or should I go for 2 rails with 25A each? 

<3 single rail.

Since you don't seem to be worried by power usage, 80Plus Gold might not appeal to you, but they are well built in any case. Weigh the costs out.

I am tired and not good with lingo.....are you saying less than 3 rails?  or are you "hearting" a single rail? 

Regardless, thank you for the help. 

Hehe, sorry, that was supposed to be a heart. I'll go to sleep now.

[yochdog]

Yeah that is weird.

That PSU is horrible though.  It is "ugly" because it only has 750W but it has that broken into 4 different 12V rails.  Each rail only has 20A. =240W which is right at what a 5970 needs.  It could be starved for power.  Have you underclocked the memory (at least down to 300) that will reduce wattage somewhat?

http://www.rosewill.com/products/698/productDetail.htm

The only other thing to try is use 1 power cable for each rail.  That way 2 rails are powering the same card.  Finding out which cable is on which rail for a PSU like that is tough so you can just try to change the plugs around.  Generally for a 5970 a PSU which either has 1 massive 12V or a few large rails makes power management easier.

SO when I go to buy additional PSU's for expansion and replacement, should I be shooting for single 12V rails with 50A+?  Or should I go for 2 rails with 25A each? 

<3 single rail.

Since you don't seem to be worried by power usage, 80Plus Gold might not appeal to you, but they are well built in any case. Weigh the costs out.

I am tired and not good with lingo.....are you saying less than 3 rails?  or are you "hearting" a single rail? 

Regardless, thank you for the help. 

Hehe, sorry, that was supposed to be a heart. I'll go to sleep now.

Lol.....thanks man.  I will be looking for some solid single rail PSU's now.  I imagine that is what is holding me back from hitting the "magic" 700 MH/s on all of my 5970's.  I wish I knew that before I bought so many of the Rosewill PSU's with 4 rails. 

[DeathAndTaxes]

Yeah single rail.  It isn't to say a multi-rail PSU can't be good but depending on the rail configuration there can be power left untapped.

I would consider this PSU to be pretty much unbeatable for making 3x5970 or 4x5970 rigs:

http://www.newegg.com/Product/Product.aspx?Item=N82E16817151109

1250W is more than enough for 4x5970 or 3x5970 rig that you want to leave upgrade open.  If you know you won't be going w/ 4x5970 1050W is equally good and saves some coins..



A staggering 104A on the 12V rail.  Would like to point out that 1248W of the 1250W is available in 12V in one rail. 


8 PCIe connectors so 4x5970 is possible without trying to fuck around w/ molex adapters.

A couple of minor points:
a) has oversized power switch which is nice (I set BIOS to turn on after AC loss and just use PSU switch to turn rigs on/off).
b) all cables are modular which reduces cable mess and makes swapping out PSU easy.
c) 5 year warranty and w/ SeaSonic you know who built it (SeaSonic) unlike other companies who just farm the work out.

[sveetsnelda]

A staggering 104A on the 12V rail.  Would like to point out that 1248W of the 1250W is available in 12V in one rail.

And I would like to point out that this is a 4 rail PSU.    The diagram on the outside is a bit misleading.  Because it's a DC to DC design, all of the PSU's power is pulled from a single 12V rail and then separated into 4 individual rails.

(Here is some more detail on the subject.  This is a review of the XFX Pro 1250W Black Edition which is just a rebadged Seasonic 1250).
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=273

This being said though, it's a *FANTASTIC* PSU.  I have 13 of them.