So, in coming up with a build for my next system, I can't seem to decide between a good quality 850W or a 1000W PSU. I've read that dual HD 6970s would run perfectly well on a good 850W power supply. So my question is, when would a good 1000W be needed over 850W?
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850W or 1000W?
- Thread starter CeZemal
- Start date
MrWizard6600
Supreme [H]ardness
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6970 TDP is 250W, its easy to see an overclocked CPU's TDP being 200W, that adds up to 700W, leaving 150 for the rest of the system? Unless you're running half a dozen hard drives, I think an 850W would be ample.
The thing is, these TDPs are based almost entirely on the concept of every transistor running a pulse-train (maximum power consumption), and that, as AMD has lamented, means you'll very rarely see those cards pull more than 200W. And if you leave power-tune enabled and leave the cards at stock frequency, they all but gaurentee it'l stay below 200W.
That said, if you're going to be over volting, disabling cool-n-quiet and all the other power saving technologies, maybe a 1000W PSU isn't a bad idea?
The thing is, these TDPs are based almost entirely on the concept of every transistor running a pulse-train (maximum power consumption), and that, as AMD has lamented, means you'll very rarely see those cards pull more than 200W. And if you leave power-tune enabled and leave the cards at stock frequency, they all but gaurentee it'l stay below 200W.
That said, if you're going to be over volting, disabling cool-n-quiet and all the other power saving technologies, maybe a 1000W PSU isn't a bad idea?
Right now, I'm thinking about CrossfireXing HD 6970s and taking an i7-2600K to around 4.5 GHz (that is, whenever they come back on sale -.-), and running 1 SSD and 2 HDDs (one for games one for storage). To my knowledge those are the main power eaters. I read a review of Silverstone's new Strider Gold 850W PSU. Apparently it can actually crank up to 950W of power if needed. It also mentioned it being perfect for HD 6970s, though they didn't actually test it themselves (the reviewer). I'm not saying I'm dead set on 850W, just wondering under what circumstances would 1000 be more optimal than 850
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Gawd
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850w would be fine. You won't be pulling 250w from the graphics cards unless you overclock them, crank up the power slider to +20%, and run Furmark. Also, Sandy Bridge parts are more power efficient then their predecessors. Sata drive = about 10w MAX...most likely 5w during average use. SSD's are 5w or less.
Anyways, to get everything at max utilization would take furmark + IBT or Prime + a hard drive benchmark. Nothing in real world usage could even remotely approximate that kind of power draw...and honestly, furmark is a pointless program. Its not very good at detecting artifacts, and only serves to cook cards and PSUs. So, you'll be fine with an 850w unit.
Anyways, to get everything at max utilization would take furmark + IBT or Prime + a hard drive benchmark. Nothing in real world usage could even remotely approximate that kind of power draw...and honestly, furmark is a pointless program. Its not very good at detecting artifacts, and only serves to cook cards and PSUs. So, you'll be fine with an 850w unit.
So for me, 1000W would be more or less excessive. Even with 2 cards pulling the max 300W (they're only allowed to consume 300W as a single card right?), that'd still leave plenty of power for everything else. I would never attempt 3-way SLI or CF, and I don't believe I'd be overclocking my video cards at all for fear of the extra heat generated. So I will continue my hunt for the best 850W PSU I can find.
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Gawd
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XFX 850w Black Edition is a nice unit. Currently on sale @ Newegg right now for a stupid cheap price. Then there is the venerable Corsair AX-850w...80+ Gold rated but more money (XFX is silver).
Cards won't draw 300w. Not unless you plan on cooling them with liquid nitrogen and increasing the voltage by large amounts.
Cards won't draw 300w. Not unless you plan on cooling them with liquid nitrogen and increasing the voltage by large amounts.
Hmmm liquid nitrogen... tempting, tempting....... Think I might pass on that one 
Though this isn't for right now, but for a build about mid-March / April-ish. I know the entire game will change by then, but I figure a power supply is one of those things that doesn't change as rapidly as other parts of a system, so I might well be able to pick one out now.
Though this isn't for right now, but for a build about mid-March / April-ish. I know the entire game will change by then, but I figure a power supply is one of those things that doesn't change as rapidly as other parts of a system, so I might well be able to pick one out now.