PSU 650W enough for a AMD FX8120 7970 Ghz Build?

[Niric]

Hello everyone! Long time lurker, first time poster. These forums have been a great resource of information for me for a long time.

If I could ask, I was hoping I could trouble you all for a little advice on my PSU situation and my new PC build.

Current PSU Corsair TX650M (http://www.newegg.com/Product/Produc...82E16817139031)

I was hoping my current PSU TX650M would support my new build but I see now it falls below the recommendations of the Sapphire recommended 750w PSU for their 7970 Vapor-X.

Here's the parts of my build that I've put together and its either in the mail or already here at this point.

PSU : CORSAIR TX650M 650W ATX12V v2.31 / EPS12V v2.92 80 PLUS BRONZE Certified Semi Modular (Retained from current build if possible)
CPU : AMD FX-8120 Zambezi 3.1GHz Socket AM3+ 125W Eight-Core
CPU Heatsink : ARCTIC ACFZA30 120mm Fluid Dynamic Freezer
GPU : SAPPHIRE Vapor-X 100351VXSR Radeon HD 7970 GHz Edition 3GB 384-bit GDDR5
RAM : 1x CORSAIR Vengeance 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 (may get another pair later)
Motherboard : ASUS M5A99X EVO R2.0 AM3+ AMD 990X
SSD : 1x Corsair Force Series 3 CSSD-F60GB3A-BK 2.5" 60GB SATA III
HDD : 1x Seagate Momentus XT ST95005620AS 500GB 7200 RPM 2.5" SATA 3.0Gb/s (Retained from current build)
Case : Corsair Graphite Series 600T CC600TM Mid-Tower Gaming Case

If you all don't think the TX650M will be enough, I was thinking of going and and getting one of these: SeaSonic X750 Gold 750W which is on an amazing deal today, but today only. So I'll order one of those by this evening unless you all don't think its necessary.

My build was made for a single solid GPU utilization, so I don't plan to do anything more than just the 7970 Vapor-X for quite a while. So I'm not looking for a PSU that can SLI/Crossfire in the future at this point. However, with I plan to play Planetside 2 and the new version of FFXIV ARR in the near future. Both games will have some serious GPU and PSU demands. I may do a little overclocking on the CPU and GPU, but I'm not certain yet.

Thanks in advance for any feedback/advice/recommendations on this!

-Niric

[lehtv]

Yeah, it's enough for your build. A system with 7970GHz consumes between 400-450W, and closer to 500W if overclocked: http://www.anandtech.com/show/6025/r...-to-gtx-680/17

[Niric]

Originally Posted by lehtv

Yeah, it's enough for your build. A system with 7970GHz consumes between 400-450W, and closer to 500W if overclocked: http://www.anandtech.com/show/6025/r...-to-gtx-680/17

I see! That's good to hear! Thank you, lehtv!

I realized I made a mistake as well and Sapphire actually says the card requires a 500W PSU not a 750W like I remembered incorrectly.

I am curious how the PSU Watts details work actually. I should probably do some more research on the subject.

I probably wrongfully assumed that the total wattage of a PSU would exceed the wattage consumption of your each of you build components under heavy load as a added total number?

In otherwords, is it actually just a requirement to provide that amount of wattage as overall capable PSU? Hmm, I'm having trouble putting this question into workds. Haha.

Let me try this- The 8120FX needs around 25W, and the 7970 Ghz needs around 500W, as long as it provides 500+W, then im in the clear? Not 250W+500W+other components = 800+W for total wattage required like I was assuming? I hope this doesn't sound like a dumb question. Haha.

Thanks again for you help!

-Niric

[Centauri]

Slightly OT: I know Zambezi stuff is getting cheap with discount codes, but Vishera is also available with some really good motherboard bundle discounts - a few pages worth. May wanna look through 'em and see if you can't swing a Vishera setup.

http://www.newegg.com/Product/Produc...cmTag=0&Page=4

Good luck with your system. Looks brutal.

[Niric]

Originally Posted by Centauri

Slightly OT: I know Zambezi stuff is getting cheap with discount codes, but Vishera is also available with some really good motherboard bundle discounts - a few pages worth. May wanna look through 'em and see if you can't swing a Vishera setup.

http://www.newegg.com/Product/Produc...cmTag=0&Page=4

Good luck with your system. Looks brutal.

Thanks! Brutal in a good way I hope! haha.

I really kicked around the choice of the motherboard a lot. I'm not at all interested in running multiple GPUs this time around. And it seems like if you want a single GPU set up most motherboards seem to be a bit overkill. But I'm certainly no pro on this stuff.

Yeah, that Vishera does look really nice actually. And not really that much more expensive. But I'm afraid I actually got the CPU already a couple weeks back. I caught on to a $20 off deal. So it was a stupidly cheap $130 price for it. I figured it was a good place to start. And hopefully they'll work with the AM3+ socket some more I can hop up to a CPU tier thats a bit more substantial. By then I hope I can delicate the funds just to upgrading a CPU instead of an entire build, like I needed. (AKA the 8120 will blow my mind for now, since I'm still using an Athlon X2 Dual core. Haha.)

I very much appreciate the input and don't mind it at all being OT. I would definitely appreciate any additional comments on the build! Some of it I believe I could still return if it was really worth it and I made a big oversight on something somewhere, thats for sure.

-Niric

[Eureka]

You'll be surprised how little a power 7970 Ghz actually uses... http://forums.anandtech.com/showthread.php?t=2280529

The 650W is a good power supply. You'll be able to xfire with headroom later on.

[Bull Dog]

Originally Posted by Niric

I see! That's good to hear! Thank you, lehtv!

I realized I made a mistake as well and Sapphire actually says the card requires a 500W PSU not a 750W like I remembered incorrectly.

I am curious how the PSU Watts details work actually. I should probably do some more research on the subject.

I probably wrongfully assumed that the total wattage of a PSU would exceed the wattage consumption of your each of you build components under heavy load as a added total number?

In otherwords, is it actually just a requirement to provide that amount of wattage as overall capable PSU? Hmm, I'm having trouble putting this question into workds. Haha.

Let me try this- The 8120FX needs around 25W, and the 7970 Ghz needs around 500W, as long as it provides 500+W, then im in the clear? Not 250W+500W+other components = 800+W for total wattage required like I was assuming? I hope this doesn't sound like a dumb question. Haha.

Thanks again for you help!

-Niric

We all have to learn somewhere. The Radeon 7970 GHz has a TDP of (I think) 250W, AMD's faster CPUs have a TDP of 125W.

TDP is Thermal Design Power. Basically, and I'm grossly oversimplifying here, TDP = Maximum power draw. If you don't overclock your components should never consume more power than that. Typical power consumption is usually lower.

Your motherboard and all other components will in all likelihood not consume more than 30w, but lets call it 45W.

So you have: 125W CPU + 250W GPU + 45W System = 420 Watts.

To sum up; this tells us you could get away a brand name PSU of as little as ~425W.

Your Corsair 650W PSU has more than enough power. It even has plenty of power left for you to do overclocking should you desire. Even if you went nuts overclocking and your power figures boiled down to something like 200W CPU, 325W GPU, 60W System (=~585w), you still have more than enough Wattage.