Quick PSU question

Duff Man Jr.

For a new machine a 600w PSU will be perfect, but I'm thinking about getting a 850w just to future proof it (and because I can).
My question is if I go for the 850w will it cost more to run (than the 600w)? Does it draw more power constantly of is there more there only if it needs it?

U_Fig

Duff Man Jr. wrote: »

For a new machine a 600w PSU will be perfect, but I'm thinking about getting a 850w just to future proof it (and because I can).
My question is if I go for the 850w will it cost more to run (than the 600w)? Does it draw more power constantly of is there more there only if it needs it?

no the PSU will only run at whatever power the hardware needs.. so if you're system uses 550w even if you have a 1000w PSU it will run at 550w

however a higher watt PSU will run less efficiently at a lower wattage

Duff Man Jr.

Thanks

Beez

IT completely depends on how much your willing to pay, a gold certified 850W PSU costing €180 will be more power efficient than a 600W costing €70.

U_Fig

get a least a n 80+ model...means it's 80% efficient then you can go up bronze gold ect. the higher the efficiency goes...but all PSU's have an efficiency curve. ie at low wattage generally they run less efficiency then reach most efficient about mid to high watt usually then decline after a certain point and get less efficient.. all PSU's are different tho. A bit of headroom is good future proofing but as far as i can see any new products that came out recently are running at lower power than previous models..ie ivybridge.

Monotype

What U Fig says is true about the efficiency curve. Keep in mind that the ratings don't even apply below 20% load (20% of 850W = 170W, which is still fairly high), so if your PC is idle a lot, it's a bit of a waste.

Quality of a PSU is much more important than looking at power ratings. A good 450W PSU could be better than a poor quality so-called 850W PSU.

I'd say plan for your build and leave a bit of room if you want to, but don't go overboard. With 850W, you're heading towards 3 graphics cards.

Serephucus

If you stick up the specs of what you're think of, it would help. Might be that you actually don't need 600W (This will power everything except a GTX 690).