What kind of power supply would I need?


Sep 14, 2009
I'm about to buy some more goodies for my pc and I am wondering what kind of power supply I will need to upgrade from a low grade 500watt.

Phenom IIx4 920, overclock to 3.7GHZ
TA790GX motherboard.
DDR2 2x2gb
ATI sapphire 5870 1gb.
Going to add around 10, 120mm fans.
Tuniq Tower 120 cooling the CPU.
And ordering a bunch of Cold Cathodes for the new case I'm making.

The reason why I need to know what kind of good power supply I will need is because I'm pretty sure a low grade 500watt powersupply won't be able to run all the new lights/fans, and all the other things I have.

And yes I maybe upgrading to an I7/Phenom II x4 965, new DDR3 board, and another 5870 sometime, so keep that in mind.

Thanks, Xion.

This are the power requirements for the 5870

ATI Radeon™ HD 5870 System Requirements

PCI Express® based PC is required with one X16 lane graphics slot available on the motherboard
500 Watt or greater power supply with two 75W 6-pin PCI Express® power connectors recommended (600 Watt and four 6-pin connectors for ATI CrossFireX™ technology in dual mode)
Certified power supplies are recommended. Refer to http://ati.amd.com/certifiedPSU for a list of Certified products
Minimum 1GB of system memory
Installation software requires CD-ROM drive
DVD playback requires DVD drive
Blu-ray™ playback requires Blu-ray drive
For an ATI CrossFireX™ system, a second ATI Radeon™ HD 5870 graphics card, an ATI CrossFireX Ready motherboard and one ATI CrossFireX Bridge Interconnect cable per graphics card (included) are required

The recommended PSU is for the entire system.

With this Antec 650W is enough for your rig.

Now, if u want upgrade your rig, the PSU is also enough to handle your new rig and the future Crossfire.
Size it:


Pick it:


The sweet spot for PSU's price / power wise is the 650 watter for an OC's machine w/ one GFX card and the 850 watter for two. yes, you can do less but remember that the best efficiency point (BEP) is at the 50% load point..... furthermore OC'ing requires stable voltages and stable gets harder the farther you get from that BEP.

I'd echo the 650 watt Antec EA-650 for your rig with the Corsair TX650 as an alternate for a moderately OC'd machine.....if you are going for real high OC's, then I'd upgrade to an Antec SG series, Seasonic X-650 or Corsair HX series.