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Thread ID: 130306	2013-04-04 23:37:00	How big of a psu do I need?	Blackandblue (14231)	Press F1

Post ID	Timestamp	Content	User
1335572	2013-04-04 23:37:00	Hey for these specs, 2500k Sandy Bridge 3.3ghz Asus P8Z68-V PRO Twin Frozr 7870 8Gig Ripsaw Ram 1 TB Seagate hardrive DVD Drive How big of a psu do I need? Would 550W be ok? And what happens if its to little and the computer is under full load?	Blackandblue (14231)
1335573	2013-04-04 23:48:00	I'd say yeah, that'd probably be sufficient, provided it's a *quality* brand and not some el-cheapo one.	Chilling_Silence (9)
1335574	2013-04-04 23:57:00	a decent 550 would be fine, though I'd be tempted to go 650.	inphinity (7274)
1335575	2013-04-04 23:58:00	Ok, thanks. What about a 550W Cooler Master PSU? But what happens if computer is put under 100% load and the 550W psu isnt enough? Would it result in fried parts?	Blackandblue (14231)
1335576	2013-04-05 00:03:00	If it can't support the load, you'll possibly get stability issues, like the PC rebooting, or BSODs etc, depending on how the specific parts you've got handle it. Some GPUs for example will simply not enter 3D mode if they don't have enough power. It's unlikely to cause immediate parts damage. I would go Corsair or Antec though.	inphinity (7274)
1335577	2013-04-05 00:09:00	Even under full load a system like that wouldn't even pull 400W. Any good quality PSU over 500w with at least 35A on the 12v rail(s) will be fine.	pablo d (15490)
1335578	2013-04-05 00:36:00	Ive looked at some benchmarks and for the 7870 Load Power Consumption - Metro 2033 results in 310 W 2500k Load Power Consumption (x264 1st Pass) Total System Power Consumption in Watts - 133W =443W I have 0 knowledge so laugh at me but 550W with 80% efficiency is 440W? Demand is 443W and power = 440w? Im really confused.	Blackandblue (14231)
1335579	2013-04-05 00:58:00	Use an online calculator like www.extreme.outervision.com They are conservative but that's a good thing, also doesn't hurt to think about whatever parts you might add in future and see how much the load will increase as well. I had a quick go and came up with 340W in which case 550W is fine. As for your load figures, depends if they measured AC usage at the power outlet or if it's DC power usage. The rated capacity of a power supply is what load it can supply to the PC not how much it uses, the efficiency is the difference. So a 443W load at the wall @ 80% efficiency would equal 354W of actual power usage on the DC output. A 550W PSU fully loaded would draw around 690W at the wall at 80% efficiency. Also cooler master power supplies are ok but they tend to exaggerate the power ratings like most of the cheaper brands do. The 550W rating can turn out to be the max load it can handle for a few milliseconds before the magic smoke comes out. I'd second the reccomendation for a better brand, Antec, Seasonic, or Corsair for example. With the good brands I'm happy running closer to the rated limit, for cheaper ones you need more cpapcity to be safe and for really cheap brands you will never be safe because they are rubbish. It's always a good Idea to have a quality PSU. Mine has lasted me through 2 upgrades and is total overkill but it gives me the freedom to install pretty much anything (850W corsair bought because I was running dual video cards at the time).	dugimodo (138)
1335580	2013-04-05 00:59:00	Ive looked at some benchmarks and for the 7870 Load Power Consumption - Metro 2033 results in 310 W 2500k Load Power Consumption (x264 1st Pass) Total System Power Consumption in Watts - 133W =443W I have 0 knowledge so laugh at me but 550W with 80% efficiency is 440W? Demand is 443W and power = 440w? Im really confused. That first load power consumption of 310W will be for the whole system (CPU, RAM etc). The 7870 itself is rated to use up to around 175W. A 550W PSU with 80% efficiency will draw 687.5W from your wall socket at maximum loading. I.E. only about 80% of the power it uses goes to powering your PC, the other 20% or so is lost as heat. PSU's are rated to how much power they can deliver to your components, not what they actually use. A 550W PSU will be good for a 300W - 400W system as higher rated (e.g. 650W) power supplies are generally less efficient in that range (their efficiency isn't a flat line between 0W and full load, it's more like a bell curve peaking somewhere around ~60% load).	pablo d (15490)
1335581	2013-04-05 01:36:00	That first load power consumption of 310W will be for the whole system (CPU, RAM etc). The 7870 itself is rated to use up to around 175W. A 550W PSU with 80% efficiency will draw 687.5W from your wall socket at maximum loading. I.E. only about 80% of the power it uses goes to powering your PC, the other 20% or so is lost as heat. PSU's are rated to how much power they can deliver to your components, not what they actually use. A 550W PSU will be good for a 300W - 400W system as higher rated (e.g. 650W) power supplies are generally less efficient in that range (their efficiency isn't a flat line between 0W and full load, it's more like a bell curve peaking somewhere around ~60% load). Thanks, that cleared it up alot :) A+	Blackandblue (14231)
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