PSU might not be enough

galex609

Junior Member
Jan 4, 2012
3
0
0
I decided to build a new pc after my birthday in september, so i bought the essentials with some of my birthday money...case, HDD, and a 450w power supply.

I for-sure thought that it would be enough, i used newegg's wattage calculator to see the best one to buy.

Now after Christmas, i just finished buying the rest of my parts, but i was told by some of my friends to upgrade my build a bit. For example, i was going to get the I5-2400, but they told me to get the I5-2500k. Also, i was going to get the R6770 VGA, but they convinced me to the R6790. Both upgraded parts require more power.

So, this morning before school, i plugged my specs into newegg's calculator and the estimated result was 452 watts! +2 more watts that my PSU says it handles.

Now what should i do? I'm a bit worried. do i keep my PSU, or should i try to return it and get something higher?

Your guy's expert knowledge could really help me out.

Also... I wanted to OC the processor, but i'm not sure if the PSU will support it anymore.

any advice is appreciated :)
 

lehtv

Elite Member
Dec 8, 2010
11,897
74
91
In general, 450W is plenty for 2500K + 6790. At full load, 2500K uses less than 100W without OC, and 6790 uses about 100W. You could up the graphics card to 6850/6870 and still be just fine.

You forgot a relevant bit of info thought - what is the PSU that you have? The actual peak and continous capacities vary depending on the exact unit. Some power supplies can't even deliver the wattage they claim, while others can deliver way more than they claim.
 

lehtv

Elite Member
Dec 8, 2010
11,897
74
91
For a 450W power supply, its +12V output (which is used by the CPU and GPU) isn't actually terribly good, looking at the specs photo on the newegg page. Two +12V rails, 14A and 16A (or 168W and 192W), with the total +12V output being 305W, apparently. I'd expect a good 450W unit to have closer to 400 watts of +12V these days.

Anyway, you'll be fine. You'll use around 200 watts of +12V power at full load, less than that during real world load e.g. gaming (because the CPU won't be stressed to max).

You should've gotten a unit with a longer warranty though. 1 year isn't very reassuring. Most good brands offer at least 3, some even 5 years of warranty.
 
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lehtv

Elite Member
Dec 8, 2010
11,897
74
91
If you can still get a refund, do so and buy a better quality unit with 3+ year warranty. E.g.

XFX 450W $35 after rebate, 5yr warranty, great +12v capacity
Corsair CX430 V2 $35 after rebate, 3yr warranty

If you can't get a refund then just stick with it. It'll handle your system fine.