Solved New GPU needs new PSU

Xfx / Pro series
December 10, 2011 at 16:39:31
Specs: windows 7, amd phenom ii x6/ 8Gb ram
I bought a XFX HD Radeon 6770 and it's recommended that i buy a new PSU that can put out 500w my current PSU only puts out 400 max from what i could find online. I'm thinking about getting a XFX pro series PSU that can put out 650w so my question is, do i go for bare minimum, or will the extra power not hurt my pc? Also what suggestions do you have so i get the most out of my purchase for any future upgrades? PSU I looked at is going for 80$.

my PC is: ASUS Essentio CG1330
CPU: amd phenom ii x6 1045T 2.8Ghz
GPU: xfx ati hd 6770 1GB GDDR5
PSU: 400W PFC (peak)
RAM: 8Gb GDDR3
1 TB HDD


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✔ Best Answer
December 12, 2011 at 14:34:40
This from the specifications of the XFX6770 card:
500 Watt or greater power supply with two 75W 6-pin PCI Express power connectors recommended (600 Watt and four 6-pin connectors for AMD CrossFireX technology in dual mode)

Your current powersupply is not going to have two 6pin connectors capable of providing over 6 amps each.

Your present PSU has two 12V rails. One @ 16amps and the other @ 17 amps.
In theory that should provide overall +12V 33amps = 396watts But note the warning second line from the bottom. Total load on the two rails not to exceed 300watts or 25Amps. Your graphics card requires 12.5amps combined from two x 6pin connectors.
Given that you should never exceed 80% of rated capacity you effectively have only 240 usable watts of +12v. The graphics card takes 150W leaving only 90W for the rest of your system. Recipe for disaster. Your current powersupply is garbage.

Goin' Fishin' (Some day)



#1
December 10, 2011 at 17:02:47
http://www.hardwareheaven.com/revie...

The "extra" power cannot hurt your system, only your back pocket. The 650 would adequately meet your needs and allow a safety margin as well as future upgrade room. I'm no expert when it comes to powersupply selection but the one you are considering appears to be a quality unit with over 80% efficiency and providing up to 53amps on the +12v rail. Good specs and a good warranty.

Goin' Fishin' (Some day)


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#2
December 10, 2011 at 17:49:29
I think its a good unit for the price as well, I didn't know anything about PSUs until I needed one. Didn't want to go for to much power and end up frying my pc.
Hoping that this new GPU will play WoW at 1920x1080 res on high or ultra settings with 35+ fps. either way i needed a new one.

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#3
December 10, 2011 at 18:21:05
You cannot fry a PC with too much power. The opposite is in fact the case. With an underpowered PSU you can overload it and when that happens sometimes it allows naked mains voltage to seek earth through motherboards and other things with dire consequences.

Goin' Fishin' (Some day)


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Related Solutions

#4
December 10, 2011 at 20:40:21
Go for it. Just think about AVAILABLE wattage as your AVAILABLE power you CAN draw upon. You ACTUALLY only use a portion of that at any time, the rest is not used and has no effect. If you got a 1000 Watt unit, it would be a waste of money, but it would not harm your system (assuming a quality unit). ONLY incorrect voltages can harm your system.

You have to be a little bit crazy to keep you from going insane.


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#5
December 11, 2011 at 07:35:38
"I didn't know anything about PSUs until I needed one. Didn't want to go for to much power and end up frying my pc"

Looks like you still don't know much about PSUs. Do you ever read the PC builder articles at Tom's Hardware? They regularly use the Antec EA-380D Green 380W unit in their gaming builds. Why? Because they know it's more than just about wattage - ALL the specs need to be taken into consideration. The Antec unit has an 80% plus efficiency rating, active PFC, combined +12v amperage of 28A, & a 3 yr warranty. Hopefully the 500W unit you chose has similar specs? Whatever you do, make sure to stick with reputable brand names & expect to pay at least $50 for something decent. Here's a few good ones to give you an example of what to look for: http://tinyurl.com/d7rogqv

And how about posting the specs of your current 400W PSU?


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#6
December 12, 2011 at 11:53:23
Here's a photo of the specs from my PSU

http://a3.sphotos.ak.fbcdn.net/hpho...

been looking for the exact model but can't find it on delta's website, if its not all about wattage and just the right specs then all i need to find out is if the 6-pin connection on it has the proper voltage then.


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#7
December 12, 2011 at 14:34:40
✔ Best Answer
This from the specifications of the XFX6770 card:
500 Watt or greater power supply with two 75W 6-pin PCI Express power connectors recommended (600 Watt and four 6-pin connectors for AMD CrossFireX technology in dual mode)

Your current powersupply is not going to have two 6pin connectors capable of providing over 6 amps each.

Your present PSU has two 12V rails. One @ 16amps and the other @ 17 amps.
In theory that should provide overall +12V 33amps = 396watts But note the warning second line from the bottom. Total load on the two rails not to exceed 300watts or 25Amps. Your graphics card requires 12.5amps combined from two x 6pin connectors.
Given that you should never exceed 80% of rated capacity you effectively have only 240 usable watts of +12v. The graphics card takes 150W leaving only 90W for the rest of your system. Recipe for disaster. Your current powersupply is garbage.

Goin' Fishin' (Some day)


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#8
December 12, 2011 at 16:43:12
Richar59 is right, did extra research, and bought a ATX LSX 750watt PSU for 75$ brand new. Has everything I need for now and later if i do any future upgrades.


Thanks for your help and advice PC is running better than I expected.


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