Hi Kyle,
got a few links for ya..
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This is copied and pasted from a review at 3D Guru (I'll post the link)
Power Consumption
One of the biggest accomplishments of the series 5000 graphics cards is the enhancement in the power design, the implementation of voltage and clock regulation is even more dynamic -- power management at a new level.
So we'll look purely at the Radeon HD 5870 now, in IDLE the GPU will clock down and lower its voltages on both GPU and memory. Have a look:
GPU Radeon HD 4870 Radeon HD 5850 Radeon HD 5870
Max. Board Power (TDP) 160W 170W 188W
Idle Board Power 90W 27W 27W
The card obviously achieves a low 27W IDLE power consumption by clocking down with several power states. Thus a low engine (core) clock frequency with lowered voltages and lower GDDR5 memory power. It's amazing though as your generic high-end graphics card would normally consume 50~60 Watts when it idles in Windows.
Things get even better though, the performance of the graphics card opposed to the last generation products has nearly doubled up in performance and design, yet the 5870 has a TDP (peak wattage) of only 188 Watts. We think that is just awesome.
Though we haven't tested it yet, ATI also incorporated a new technology feature called ULPS -- Ultra High Power State for multi-GPU configurations. We need to look into this, but typically with multiple GPUs installed you'd have a high IDLE power consumption, this seems to have been improved. More on that in another article though.
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This next article was for the 4870 but as the 5870 uses power even better then consider it a reasonable guide for power requirements..
n my view the Radeon HD 4870 series requires you to have a 500 Watt power supply unit at minimum if you use it in a high-end system, and I think that's barely on the safe side. Also recommended is 32 AMP's (I would try and get 36 amps if you can) on the 12 volts rails for stable power distribution (in a single card configuration). Please make note of the fact that the card uses two 6-pin power connectors.
There are many good PSU's available, over the years we reviewed a lot of them and have loads of recommended PSU's for you to check out in there, have a look. Things that can happen if your PSU can't cope with the load?:
bad 3D performance
crashing games
spontaneous reset or imminent shutdown of the PC
freezes during gameplay
PSU overload can cause it to break down
Here are some power supplies which may be used as a replacement. Power supplies should never be skimped on as they are sooo important, as the article above implied, incorrect power reserves will cause all sorts of horridness...
Newegg.com - Antec earthwatts EA500 500W Continuous Power ATX12V v2.0 SLI Certified CrossFire Ready 80 PLUS Certified Active PFC "compatible with Core i7" Power Supply - Power Supplies
Newegg.com - OCZ ModXStream Pro OCZ600MXSP 600W ATX12V V2.2 / EPS12V SLI Certified CrossFire Ready 80 PLUS Certified Modular Active PFC Power Supply compatible with core i7 - Power Supplies (very nice)
Newegg.com - CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 Power Supply - Power Supplies
I hope thats enough for now lol..
