Will my PSU handle this?

[Tim]

I currently have a Corsair CX600M running the following system. My question: Will I be able to add a second matching video card for SLI, or am I going to be forced to upgrade?

i7-4790k, no overclock
Asrock z97 Extreme 4
16gb (2x8) DDR3-1866, no overclock
GTX-980 (Evga superclocked)
1 SSD
5-channel fan controller (up to 35w per channel) handling all fans for my computer (2x120mm, 4x140mm)
Corsair h80 (fans on controller listed above)
Bluray drive (can unplug, I never use it)
3 usb devices that require power: Gaming kb, mouse, headset. The mouse and headset are wireless and only require power for charging.

I can't think of anything else that I have that would be a power draw.

Thanks.

 

[Corsair Joseph]

With that card in SLI, I would go for a PSU that's around 800watts range.

 

[Tim]

Have any 800 watt psu's floating around that you need me to test indefinately Joseph?

 

[aaksheytalwar]

Get a 1000w unit so you have room for gpu upgrades, over looking etc with dual cards.

 

[Tim]

Get a 1000w unit so you have room for gpu upgrades, over looking etc with dual cards.

I don't really see the need to do that.

 

[lehtv]

Are you gaming on higher than 1080p ? If not, then single 980 should be just fine for now. If yes, then it could well be worth upgrading straight away to 980 SLI, along with one of these:

Corsair RM850 is on a sale for $110 after rebate and promo @ newegg.
EVGA 850W G2 $117 after rebate @ NCIX.

EVGA's ball bearing will ramp up quite easily and will definitely be noisier than the RM850's rifle bearing fan. I'm not sure if that will matter over the noise of everything else, hard to say as I haven't heard either PSU run first hand. But in the end it comes down to whether you value 10 year warranty more than guaranteed quiet operation.

 

[Tim]

Are you gaming on higher than 1080p ?

I've got a Samsung UHD monitor and would like to take full advantage of it. The single 980 just isn't enough.

 

[lehtv]

Ooohh, 4K. GTX 980 SLI will work fine for the time being but I'd be prepared to swap them out for 980 Ti SLI. A single 980 is perfect for 1080p, but for a resolution that requires 4 times as much rendering, 980 SLI will only go so far...

Of course, budget might get in the way of all that.

 

[Tim]

Of course, budget might get in the way of all that.

Yup. 980 SLI is the best I'll be able to swing, but only after I offload some items in the FSFT forums lol.

 

[BonzaiDuck]

I don't really see the need to do that.

I agree . . . sort of . . .

With a brand-new Seasonic 650W PSU, I upgraded a GTX 970 to SLI and bought the second card. I could say I'm a dunce: maybe I was considering a PSU upgrade: I just decided to shoot first and analyze later.

My systems are overclocked from their stock 95W TDP to as high as 137W under full CPU load. I measured the draw at the UPS with its software; tracked the CPU wattage separately with HWMonitor.
With the 970s mildly OC'd (below the 110% power limit), 650W is still ample. The system will NEVER draw the combined power of full CPU load plus Kombustor load (tweaked to assure full load on both cards). I can probably add another 80W of power-consuming parts.

But even so. Good PSUs can sustain maybe 100W higher than their rating.

As for the Corsair, at 600W -- I couldn't say. First -- WHO REALLY manufactures that unit? How much mileage has it racked up? If the OP won't OC has processor OR his GPUs, that by itself gives him about 100W estra in wiggle room -- or so I'd think.

At 600W (and "Corsair") -- I'd start looking as you ferret away some dimes and nickels. Run some tests; do some calculations. Maybe, by that time, you might assure yourself that you needn't buy a new PSU. Conversely . . . you do what needs to be done . . .

I also found this Tom's Hardware forum exchange:

http://www.tomshardware.com/answers/id-2109845/corsair-cx600m-bad-quality-psu.html

 

[TemjinGold]

So you only sort of agree that the OP doesn't need a 1000w?

 

[BonzaiDuck]

So you only sort of agree that the OP doesn't need a 1000w?

I think a 750 would be ample if he's overclocking, and I think a GOOD 650 would be ample if he isn't. Who recalls the stock load power-draw of a GTX 980? Not overclocking either CPU or GPUs, I think that's a fair assessment.

Now if he's going to add several more cooling fans and a pile of hard drives, then 750.

 

[Tim]

I think a 750 would be ample if he's overclocking, and I think a GOOD 650 would be ample if he isn't. Who recalls the stock load power-draw of a GTX 980? Not overclocking either CPU or GPUs, I think that's a fair assessment.

Now if he's going to add several more cooling fans and a pile of hard drives, then 750.

The only thing I plan on adding is the video card. My cooling is more than sufficient and I will not be needing any other fans, or any other hardware for that matter. I have two Phantek 120mm fans on my Corsair h80. I have two 140mm phantek fans on the side panel feeding air at to the video card(s), and two 140mm phatek fans as intake on the front of the case. All of these fans are hooked up to a NZXT sentry mesh 5 channel controller, with the two 120mm fans for the h80 on one channel, and the 140mm's each on their own channel. I put the all of the fans on low for general computing (web browsing/netflix/etc.), and I put them on high during gaming. I'm also running a custom fan curve on the video card for a little extra cooling during heavy video card loads.

Also, if it matters any, the Corsair 600watt psu I have now is only about 7 months old.

A little more information on my hardware might help here also. I will probably remove the bluray drive.
The SSD is a Samsung 850 evo, which is low on power consumption from what I've read.

 

[Tim]

So should I go for this?

http://www.amazon.com/EVGA-SuperNOV...0486796&sr=8-2&keywords=evga+power+supply+750

Or This?

http://www.amazon.com/dp/B00KFAFRW6...colid=RXTVCHVPP99Q&coliid=I1HMW1KYNC4KP&psc=1

 

[BonzaiDuck]

So should I go for this?

http://www.amazon.com/EVGA-SuperNOV...0486796&sr=8-2&keywords=evga+power+supply+750

Or This?

http://www.amazon.com/dp/B00KFAFRW6...colid=RXTVCHVPP99Q&coliid=I1HMW1KYNC4KP&psc=1

There's another concurrent thread which explains a bias I have for selecting Gold over Bronze. It was remarked that the Gold might make up for the price differential with more efficiency at lower wattage, but you'd have to check test results and specs. And apparently the Bronze-to-Titanium spectrum is just a matter of efficiency differences. Truth be told, if your system idles in a range of 90 to 130W total power consumption, why not get the Gold model?

If you're not planning any big expansions over the system's lifetime, you could still go with a 650. So at least get the more efficient of the 750's.

 

[lehtv]

Definitely get a Gold unit for a SLI PC, especially if you plan to keep the unit for a long time. It will save enough electricity during its lifetime to pay back most if not all of the initial cost difference. Plus you get longer warranty and quieter operation.

If you're not planning any big expansions over the system's lifetime, you could still go with a 650. So at least get the more efficient of the 750's.

Since he's upgrading specifically for 980 SLI, a 650W unit is out of the question

 

[Tim]

Definitely get a Gold unit for a SLI PC, especially if you plan to keep the unit for a long time. It will save enough electricity during its lifetime to pay back most if not all of the initial cost difference. Plus you get longer warranty and quieter operation.



Since he's upgrading specifically for 980 SLI, a 650W unit is out of the question

Two different Psu calculators show my proposed systems power draw at 590 watts 100% load. Please explain why a qualityy 650 watt psu is not sufficient?

 

[lehtv]

Because you're not supposed to run a PSU that close to its maximum load for prolonged periods of time. Not only will it shorten the PSU's life span, but its fan will also make much more noise when close to maximum load.

A good rule of thumb: always keep your load watts between 50% and 80% of rated wattage. 50% is where a unit is typically most efficient, and if load watts are below 50% you're probably going to be idling at such low load that efficiency also suffers while idling; and 80% gives you enough safety margin to ensure long term reliability and good life time.

Even at 80% load however, most units will sound like jet engines. Take Corsair RM series for example - these are unit specifically designed for quiet operation, yet an RM750 at 600W (=80%) already sounds the same it sounds at full load: http://tpucdn.com/reviews/Corsair/RM750/images/fan_noise.jpg

I'd try to stay at 60-70%. For your setup, 750W is sufficient because:

4790K = 80W
GTX980 = 200W *2 = 400W
The rest = 50W
-> total = 530W

530W/750W * 100% = 71%. This represents a scenario where both GPU's are being fully utilized, and the CPU is also working hard. Most of the time you'll be closer to 500W or slightly below. If you're particularly concerned about noise then 850W is an even safer bet than 750W, without being overkill.

 

[Tim]

After checking some reviews, I ended up getting the 750 watt EVGA supernova g2 gold PSU. It's working great so far.

 

[lehtv]

Nice to hear!

 

[Tim]

I appreciate the help