Get an HX850 and be happy. The ideas you are having for the future really point at getting a new, bigger PSU.
if there are no specials at the moment on an hx or ax series unit, and you only have the money for one gtx 580 for now, wait on the psu until some deals come out, then grab one...despite what jamie said, the unit will happily run a gtx 580...
Lenny is correct in that you do have to make allowances for other components such as HDDs and add in cards but compared with a GPU or CPU they are proportionally much less significant. I have linked a post I made last year that has my thoughts on estimating PSU load. It is a bit dated now but does give the basic idea.
Thanks guys for the help. I think i'll go with the 850HX bit of peace of mind now and should run 2 gtx 580 if need be. i only have 1 ssd and 1 sata drive so they shouldnt be a prob
nice, takes a different route on calculating psu load. only thing i think you got confused on was multiplying the estimated load by .8...didn't read the whole article but i assume you were thinking about 80% efficiency units...how that works is basically for every 100 watts being pulled from the unit, 80 watts are used by the pc...so if a pc needs 320 watts to run, theoretically a 320 watt unit would be fine, but if it was rated 80% it would be pulling 400 watts from the wall...that article was old so maybe you know that now, but since you referenced it i thought i would clarify lol...i suppose...dependant on whether the psu enjoyed his days at the office working or surfing the net...
It should be dividing by 0.8. I will check if I have made a typo. The idea of dividing by 0.8 is just to give a bit of headroom so that the PSU isn't working too hard and there is an allowance for cap aging.
I can't quite decide what you are saying... Run a GTX580 on a HX520? I have a HX520 that is a few years old now (I can't recall off the top of my head), and really wouldn't like to run a 580 off of it. Not saying it is bad, on the contrary, it is an amazing little PSU and I love it to bits, but an overclocked system with a 580? I would just about feel happy with a 570 on it. Any more and I think it is pushing it. I am no expert in these matters though, and I don't even know how much my system draws from the wall so... Please do try it - I'd like to see what I can run from it!
850w is plenty for sli 580's even with some heavy overclocking, most i have seen from the wall with my setup is just under 900w (810w @ 90% efficiency), that was running 3Dmark11 on the P preset with the cpu @ 4.2GHz @1.38v and the gpu's @ 950/2025 @1.15v.
What does the GTX580 pull in terms of amps/watts? IIRC the HX520 had about 40 amps total, so you'd have to be careful on it, TBH, I wouldn't personally try to run one on it. All the best whatever you decide.
you guys need to read the thread or even try google...or both bit-tech's test rig with a hungrier cpu only pulled 360 or so from the wall under load, meaning that the actual watts needed by the rig were in the 300-315 range... now, if you need that spelled out further, i feel sorry for you, but here it is...that means a 325 watt psu could run that rig...it would be running near 100% obviously, but it could...so, that means a 520 watt unit will run it with around 200 watts of overhead...to spell it out further, it can run it even with an oc on the cpu/gpu...even though it's 3-5 years old... if his hx520 is a typical corsair unit, it will be more than enough to run that rig with a single gpu, with the rig overclocked, with a couple hdd's and a sound card... that's plenty...the real issue will be a lack of a pci-e 8-pin...but still shouldn't be a problem with the corsair...just plug seperate molex cables into the adapter...
Right, so i'm definatly going to be looking at a 850. Has anyone used one of these? If so how does it rate against the hx850? 850W be quiet! Dark Power Pro P9 Modular ATX2.3 80PLUS Gold Power
sexy...i think bit-tech has always had a fondness for bequiet...havent heard anything negative about them... no reviews on the sites i look to, but an hx is only a little more on that same site, and gives you a seven year warranty vs three on the bequiet...think i would go hx...sure it's "only" silver rated, but i'd rather have the warranty over the small efficiency gain
Amps is more important than watts, it's advised that for a single 580 u need 42a on the 12v rail for the entire system, the HX520 has 3 12v rails each of 18a, running a single 580 on that psu is possible but not advised, he would really have to ensure he spreads the load evenly like a seperate rail for each connection to the 580 and the other to the mobo.
not sure why amps are more important than watts...but ok... those are suggestions, and they are always high...i know a thing or two about this, so trust me...who advises against running a single 580 on that unit? you? a few others that have no clue? i'll take it under advisement... for the record, its actually a single rail unit, marketed as three rails because that was the buzzword at the time. based on some reviews it looked like it might be 2 rails, with no ocp individually...either way, it has all the amps his pc needs...
Given a constant voltage, Amps are directly proportional to Watts. If a rail can deliver the enough power it will deliver enough current.
missed your response...maybe it did divide...either way, the overhead is a valid reason...just making sure lol
^ This. It scares me how blaze people are about PSUs. 'Oh yeah I got a 850W PSU, but it's only just enough'. Let's put that into perspective - my microwave is 850W. Can you imagine running a PC for hours at a time that draws the same power as a frickin' microwave? Since close to 100% of the power consumed is turned into heat, that's a LOT of heat to dissipate. I don't even think my triple 120mm radiator can dissipate that kind of heat. I ran a dual Xeon 3.6Ghz (The P4 kind...) workstation with dual 7800GTX graphics cards for years with an Enermax 650W PSU. PSUs have a relatively narrow band of maximum efficiency, dropping off massively if you under-utilise the PSU, or if you're near the top. It's quite feasible that a PC will draw less power with a 600W PSU than a 1000W simply due to efficiency. 1KW PSUs are for people rocking 3 GTX 580s. Power consumption would be higher than my oven since the oven uses a couple of KW - but only in bursts once warm.
