Power Supply question

gammaray57

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Hey everyone! I am currently in the works of building a new gaming computer and I need to make sure my power supply works with the items I have purchased. The graphics card I am getting says reccomended 500w and I currently have a 550w, and I also did some research and I found that it actually only consumes around 310ish watts under load, but I still just want to make sure I have plenty of power for my parts.

Here's what I got:
MSI Z77A-G45 Intel ATX Motherboard,

Core i5-3570K Ivy Bridge 3.4GHz Quad-Core Processor

SAPPHIRE 100352-2L Radeon HD 7950 3GB 384-bit GDDR5 PCI Express 3.0 x16
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and I want to make sure it runs on my
OCZ Fatal1ty 550W Modular Gaming Power Supply
(Here's the newegg link for details:Newegg.com - OCZ Fatal1ty 550W Modular Gaming Power Supply compatible with Intel Sandybridge Core i3 i5 i7 and AMD Phenom)

Please let me know if i need to upgrade my psu, and if I need to provide any more info about the parts I'm using!!!
 
lol same cpu and same gfx card.. i use an 850w that works great with them. 550w seems a bit sort on demand for the components. i run duals though.
 
The SAPPHIRE 100352-2L Radeon HD 7950 3GB 384-bit GDDR5 PCI Express 3.0 x16 has 2 x 6 pin power connectors, something like a 700 / 750w (branded) PSU would be better as you have other components to power.

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The reason the recommended PSU is higher is because your CPU and other components use up electric too.

550w should be good enough, however that PSU is a 550w MAX power, not continuous.

If you are going to shell out for a new PSU go 750w Continuous power with bronze 80+ or better.

This way it will support your rig, and any future upgrades, to save the cost again down the line.
 
another think to add is that the PSU will get more hot and be louder the more % load it uses.
That's also a good reason to think about giving the system the extra WATT.
 
The 550W that you have is adequate.

The card doesn't take 310ish watts. I think you are confusing full system load with just the graphics card load.

A HD 7950 peaks at 188W under full GPP load, less under full rendering load. (Power Consumption : Radeon HD 7950 3 GB: Six Cards, Benchmarked And Reviewed).

The CPU you have is pretty decent effeciency at about 100W tops, then the MoBo, RAM, HDD etc is probably another ~75W maximum.

So, that's more or less 365W using rough, safe, numbers - getting close to the 310W you say you researched, I reckon you are getting mixed up with system load.

Although a power supply is important, a general rule of thumb is calculate what you need (say the 365 above) then add another half for over provisioning. so we're talking about 548 - aka 550W. Hence that 550W OCZ PSU you have will handle that load very comfortably! No need for another PSU! Quality is more important than big wattage numbers when you have an adequate PSU - and the OCZ is quality enough. Don't waste your money - it's something you can consider in future when/if you go Crossfire or what-not.

Think of it this way, your system under full load (rarely achieved) will max at just 66% of the PSU rating! And this is using rough, on the safe side, numbers.
 
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