Quad SLI part deux: Build It Yourself

Originally Posted by Tim S
Power usage is related to the components inside, and the power supply efficiency. As far as I know, if you're using a 480W PSU and loading it 100%, the efficiency is worse than a 1000W PSU with the same components and thus it will technically cost you more in terms of electricity bills.

Agreed. As a quick and dirty example, a quick google search shows measured idle power consumption figures in this region:

2 x Reference NVIDIA 7800GTX 512's - 177W
1 x XFX's GeForce 7950GX2 XXX Edition - 154W

So therefore, on idle, the quad SLI power consumption would be only 131 Watts (74%) higher than a pair of 7800GTX 512's.

On load, whe results were even more impressve:

Reference NVIDIA 7800GTX 512's - 401W
XFX's GeForce 7950GX2 XXX Edition - 284W

This means that on load, the quad SLI power consumption would be only 167 Watts (41%) higher than a pair of 7800GTX 512's.

So claims of "power consumption the same as a 1kw electric fire" may be a little exaggerated. ;) Additionally, if the 1KW PSU was 90% efficient as opposed to a 550W PSU that was only 80% efficient, the power for a system drawing 300-500 watts reduced by a further 30-50W respectively! :)

As a bit of extra info, I test ran my quad setup from my original HIPER Type R 580W supply at an ambient temp of 30C for about an hour in a 3DMark 06 loop, and it worked perfectly. I think Nvidias recommendations are a little pessimistic in order to prevent being overwhelmed with support problems due to inadequate or low quality PSUs. :)

I would have liked to see some 3dmark scores... I know they arent the be all and end all but still it would have been nice

Originally Posted by Tim S
I think power requirements are going up with next-gen GPUs.

i seriously hope not, and i seriously hope intel makes a graphics card that is powerfull and cool and power eficient so nvidia and AMD get the hint and do the same.

I want to see someone watercool one of these :P

Originally Posted by mattthegamer463
I want to see someone watercool one of these :P

Well, the waterblocks are already out there for them. It could be a worthwhile investment too because the default memory clocks on the GX2's tend to be throttled back more than the comparable 7900. This is mainly because of the temperature rise in the upper card due to the ventilation restriction and heat convection from the second card sandwiched just 15mm below it.

If you can draw the heat out of the core and the RAM by another method, ie water, then the percentage gains should be considerable, though from what I have read, this tends to result in a fairly minimal performance increase in quad setups.

I'm pretty sure they're available with water blocks from the factory. Shouldn't be too hard.

are these the psus that come with the nice leather case?

Originally Posted by sunnyg
are these the psus that come with the nice leather case?

The PC Power & Cooling one doesn't, but Tagan's 900/1000W unit does. :)