Need to upgrade psu?

minidruid

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Jun 13, 2011
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Looking at picking up a hd 7950 but am unsure if my current power supply could handle it. If i ran everything stock i think it would be fine but i want to keep my cpu overclocked and overclock the gpu as well. here is what my pc would be with the new graphics card.

My power supply is 550Watt Antec PSU http://www.newegg.com/Product/Product.aspx?Item=N82E16817371016

MSI 870s-g46 mobo
8gb ddr3 1333 gskill ram
AMD Phenom II X4 955 BE 3.7 ghz (OC)
COOLER MASTER Hyper 212 Plus
sapphire Radeon 7950 (OC)
Windows 7 64bit
1 TB hdd
 

clutchc

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The HD 7950 requires 200W and draws16.7A from the +12V rail(s) when under max demand. Your stock PhII is a 125W processor that will draw 10.5A from the same rail(s). Even more when O/C'd. With a HDD running and the other +12V components in the loop, you will be putting quite a demand on the PSU's 444W +12V rail(s). That PSU probably will work OK, but it will be very inefficient at that level of demand. I'd make that my next upgrade if you go with that card.
 

minidruid

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Jun 13, 2011
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I have been considering just hoping over and buying a new mobo and i5 which has considrable less power draw than my current cpu. Think i could get away without having to replace the power supply at that point?
 

prototype18

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Well the I5 consumes less power and would be better.

Your current PSU provides 32Amp on the 12V rail = 384W

So ~210W GPU + ~125W CPU =335W

15W Hdd 16W Ram 25W Dvd = 391W

Add some OC maybe and u passed the limit with 25W +.

So that PSU wont work.

You a new PSU .

If you can tell me your budget i can give you one PSU.
 

hdeezie80

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Jul 18, 2012
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Yeah that wouldn't do too well for overclocking, 700-800W should be able to handle any further upgrades 800 would be optimal since PSU's tend to degrade overtime. Anything over that would be way overkill, make sure you get a decent brand too, power supplies degrade overtime and the cheaper ones will lose a significant portion of their wattage with in the first year or completely blow out, you should be able to pick one up for around 150-200.
 

4745454b

Titan
Moderator
LOL. I love how two different people looking at the same PSU come up with two different numbers for the total output. (444 vs 384) The PSU label shows the 3 12V rails sum up to 444W so lets use that.

125W CPU + 200W GPU + 50W for other stuff = 375W. (16W for ram???) Your PSU will be fine. I'd be careful about OCing heavy but you should be ok with that PSU.
 

4745454b

Titan
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Sorry, but I still disagree. Everything I've seen on ram says 2-4W per stick. And your talking double that.

Still on the limit? He's at 84.4% of total output. A bit above the 75% for optimum efficiency but hardly near maxing the unit out. Which review said it won't output 550W? Someone linked a review to the VP-450 (the 450W basiq model basically...) which output over 500W in the overload test. I find it hard to believe that a modern Antec 80 rated unit can't do full output.
 

4745454b

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"The spec for DDR3 memory at 1.5 Volts would provide a max of about 8-11 watts per module".

Where is that from? How nice you quote something but don't give someone the chance to review. Try something like this.

http://www.kingston.com/datasheets/KHX16C9P1K2_16.pdf

Maximum Operating Power 2.580 W* (per module)
(DDR3-1600 CL9-9-9 @ 1.5V)

This is for a 2x8GB kit from Kingston at 1.5V. You are looking at just over 5W for both sticks. This is in line with what I've heard before. If you have a link that shows 8W per stick of DDR3 or the Antec 550W PSU that the OP has only outputting 3xxW then I'd be happy to review. But so far you are making claims that don't match with what I've heard, and not providing any backup to show how you got that. He'd be using around 85% of what his PSUs 12V rail can do. (444W, not the 550W that its rated for.) A bit high, but nothing to worry about.
 
For the Sapphire Radeon HD 7950 OC with 3 GB GDDR5 the measured power consumption (ht4u.net) from the +3.3V and +12V power lines of the PCIe x16 slot and from the +12V PCIe Supplementary Power Connectors is:

Gaming using Factory Clocks: 154.99 Watts

Gaming while OC'ed to 990 MHz Core and 1575 MHz Memory: 175.85 Watts

FurMark using Factory Clocks: 203.46 Watts

FurMark while OC'ed to 990 MHz Core and 1575 MHz Memory: 229 Watts before throttling kicks in
 

4745454b

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Moderator
That would be card only. If you take the Furmark number and add in the CPU and rest of system you are around 375W. (Someone has mentioned that before.) If you have 444W then you are fine. Seriously starting to wish this thread was closed by now...