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Is my existing PSU good enough for new build?

Last response: in Components
October 10, 2009 7:12:12 PM

I already own this OCZ GameXStream 600 W PSU -

I'm trying to figure out this PSU will work with a new rig I plan on building. Here is the basic setup:

i7 920 - Plan on overclocking

Not decided which exact model I'm getting

6GB DDR3 Ram

ATI 5850


1 DVD RW Drive

2 120mm fans

This website -

tells me this setup requires 378 watts so I'm thinking my existing PSU seems fine.

Will I be okay?
a c 140 ) Power supply
October 10, 2009 7:28:18 PM

I would think so .... my experience of late is limited to the Antec Signature and Corsair HX series where if it says 600 watts, you can be sure it can deliver 600 watts.

I ran your system over at

and got 466 watts w/ 85% TDP, 90% load and 25% capacitor aging. Had to use a 5870 as the pick-list didn't include a 5850 and I was too lazy to look it up :)  so this is high

We're note exactly done yet and you do want some headroom between where you are routinely operating and what your peak rating is. If designing a new system, I'd look for 466 x 1.5 or 700 watts ..... for long term stability and efficiency.

In that case I'd probably select select a 650 considering the 5850/5870 thing but for your situation 600/466 (less actually) is still about 1.3 which is certainly within the safe range even w/ a 5870.
October 10, 2009 7:43:05 PM

Great. Thanks for the quick reply. I figured it was a touch underpowered, but that it would suffice. I might buy a second 5850 at some point and when/if I do that I'll go for a 750/800 watt PSU.
Related resources
a c 248 ) Power supply
October 11, 2009 2:27:51 PM

The official ATI recommendation for a pc system with single 5850 video card is a 500 watt power supply.

The general rule of thumb is a high quality 500 to 550 watt power supply with sufficient current (amps) on the 12 volt rail(s) can easily power a system with any single video card made.

You should be okay for now. However, if you add a second 5850 then you will have to upgrade the psu.
October 12, 2009 7:02:03 AM

Yes, you got your base covered with that PSU rating. Keep in mind though that further upgrades could be more demanding. As Johnny said "you will have to upgrade the PSU" that is if you opt for a crossfire or add other components.