Power requirements out of a PSU these days?

[TheVrolok]

Hey folks, haven't upgraded the core of my system in just about 6 years and I've started looking. I'm one of those guys who simply stops paying attention to the hardware when I'm not in the market to look, but now that I'm looking to upgrade, I've gotta see what the standards are. My real quick question is why kind of power output are we requiring out of our gaming systems these days?

Nothing too high end, thinking in terms of a budget motherboard (ASRock Z75 Pro3 LGA 1155 Intel Z75 ), Core i5-2500k, Geforce GTX 660, 1 optical drive (DVD now, possible BRD in the future), 2 HDDs (7200 SATA, might swap to 1 small SSD system drive in the future), 2x80mm Case Fans, 3x120mm Case fans. Nothing overclocked.

Currently have a 620w modular PSU, I feel like I might be cutting it too close with that for my intended rig, though? Would a 750 do it comfortably?

 

[Sleepingforest]

620 is enough for a overclocked CPU and single GPU for sure; it's also enough for an overclocked CPU and two Nvidia CPUs.

This assumes, of course, that your PSU came from someone reliable (Antec, Seasonic, Corsair) and not crappy manufacturers like Diablotek or Logisys (or unbranded).

 

[TheVrolok]

620 is enough for overclocked CPU and single GPU.

With good efficiency yea? Just used http://www.extreme.outervision.com/PSUEngine as a calculator and recommended about 600w, so if my Corsair 620HX is putting out peak efficiency I'm good? I'm still leaning toward maybe a new 750 (a few deals out there right now for sub 100 dollar 750s) so that I have some wiggle room? There's a possibility I'll upgrade the GPU at some point, but will never go dual GPUs.

This assumes, of course, that your PSU came from someone reliable (Antec, Seasonic, Corsair) and not crappy manufacturers like Diablotek or Logisys (or unbranded).

Just caught your edit and was thinking the same, my current PSU is as mentioned above a Corsair 620HX. Newegg is running a fairly solid (appearing) deal on the SeaSonic X750 (http://www.newegg.com/Product/Product.aspx?Item=N82E16817151087) for the next 2 days and was wondering if that might be a good choice to give the aforementioned wiggle room. Also, it'll leave me a spare PSU to power my old components if I put them in one of my spare cases.

 

[Sleepingforest]

It's not necessary. A GTX 670 only draws 225W; with a 100W TDP CPU, you can safely run 2 670s (all your fans, HDDs, and other components probably draw 15W together AT MOST).

Efficency is a measure of "power drawn" vs "power needed" -- so an 500W 80% efficient PSU and a 500W 90% efficient CPU can give the same power--the 90% one will just take less from the power outlet to do it.

 

[TheVrolok]

It's not necessary. A GTX 670 only draws 225W; with a 100W TDP CPU, you can safely run 2 670s (all your fans, HDDs, and other components probably draw 15W together AT MOST).

Thanks for the heads up. I still may pick up the SeaSonic deal just so I have a spare PSU and can then still use my Q6600/GTX 285 in a spare system, but appreciate the knowledge that the 620 could suffice and the 750 should have room for a GPU upgrade in it.

 

[TheVrolok]

Just read a quick review of the Gigabyte GTX 660 on Tom's and it seems like under load the card draws 320w, a little more than the estimate above.. though I imagine with the somewhat limited other sources of draw the 620 may still cut it, and the 750 surely would?

 

[lehtv]

320W? No, GTX 660 draws around 120W if I recall. With only one 6-pin connector the card is limited to max. 150W in total anyway. Can you link the article you read?

 

[Torn Mind]

The whole system has a peak draw about 320 watts. Usually, the system is not always going to be pulling peak wattage. The test system also has a 3960X, which is more power hungry than the 2500K.

I'm not sure if it is AC power or DC power, but it is most likely AC power because it is easier to measure.

http://www.tomshardware.com/reviews/geforce-gtx-660-geforce-gtx-650-benchmark,3297-23.html

 

[TheVrolok]

The whole system has a peak draw about 320 watts. Usually, the system is not always going to be pulling peak wattage. The test system also has a 3960X, which is more power hungry than the 2500K.

I'm not sure if it is AC power or DC power, but it is most likely AC power because it is easier to measure.

http://www.tomshardware.com/reviews/geforce-gtx-660-geforce-gtx-650-benchmark,3297-23.html

You're totally right, I read the chart far too quickly (gf was rushing me out the door for breakfast date). Exactly right, 320w SYSTEM power draw at peak. Thanks for the critical read.

 

[Eureka]

Which means for one GPU and one CPU, you could get by with 500W. For any card out there right now, including the Titan. 750W gives you headroom to SLI comfortably, but you could SLI and CF with less than 600W, just that you won't have much headroom.

 

[mfenn]

A 620HX is plenty of power for any single-GPU system. Don't go spending $80-$100 on a new PSU when that could instead be put back into the GPU or CPU. $100 is the difference between a GTX 660 and a 7950.

 

[TheVrolok]

A 620HX is plenty of power for any single-GPU system. Don't go spending $80-$100 on a new PSU when that could instead be put back into the GPU or CPU. $100 is the difference between a GTX 660 and a 7950.

I considered that, but to be honest, without a new PSU, I have no way to power my current rig once I put it in a spare case. Can get a 750w modular SeaSonic for like 85, and that way I won't just have my old components (Q6600/GTX 285) just sitting around. Great advice, though.

Also, I've done some thinking, and I'm going to force myself to hold off another 2 months or so for my upgrade. Just not in a great place (geographically/housing wise) to receive multiple packages.

 

[Termie]

Vrolok - just to give you some perspective and keep you from buying a 750w PSU...

My OC'd 3770k and OC'd GTX670 pull 285w from the wall under max load or about 250w from the PSU. Even with a second GPU in SLI, it would only draw 475w from the power supply.

My i7-860 and 7870 (which would be very similar to the system you're building) pull 225w max.

Please do not buy a 750w PSU for your new rig. It is nothing like your old one in terms of power use. A high quality 500-550W model will be more than sufficient.

 

[Insert_Nickname]

Vrolok - just to give you some perspective and keep you from buying a 750w PSU...

My OC'd 3770k and OC'd pull 285w from the wall under max load or about 250w from the PSU. Even with a second GPU in SLI, it would only draw 475w from the power supply.

My i7-860 and 7870 (which would be very similar to the system you're building) pull 225w max.

Please do not buy a 750w PSU for your new rig. It is nothing like your old one in terms of power use. A high quality 500-550W model will be more than sufficient.

So true, my 3770+HD7870 pulls a mere 250-270W at the wall. Everything over 500W is not necessary for anything other then SLI/Crossfire...

 

[TheVrolok]

Vrolok - just to give you some perspective and keep you from buying a 750w PSU...

My OC'd 3770k and OC'd GTX670 pull 285w from the wall under max load or about 250w from the PSU. Even with a second GPU in SLI, it would only draw 475w from the power supply.

My i7-860 and 7870 (which would be very similar to the system you're building) pull 225w max.

Please do not buy a 750w PSU for your new rig. It is nothing like your old one in terms of power use. A high quality 500-550W model will be more than sufficient.

Interesting. Thanks for the numbers! After spending so much time in OT/P&N, it's amazing to see what a friendly/helpful place Gen Hardware is. :wub:

 

[Termie]

The thing about gen hardware is no one has an ax to grind. Just a place for people to get non-fanboy and non-political technical advice.

By the way, if you can nab the Seasonic X650, SS660, or X750 on sale for $90, I won't try to talk you out of it, because they offer not just wattage but worthwhile features over 500w units at $20-30 less. But you still won't use the power!

 

[mfenn]

Interesting. Thanks for the numbers! After spending so much time in OT/P&N, it's amazing to see what a friendly/helpful place Gen Hardware is. :wub:

Stop by more often, we :wub: you right back!

 

[ElFenix]

Interesting. Thanks for the numbers! After spending so much time in OT/P&N, it's amazing to see what a friendly/helpful place Gen Hardware is. :wub:

<3 general hardware

 

[Termie]

<3 general hardware

LOL, gen hardware must be a dream come true for moderators!

 

[VirtualLarry]

My OC'd 3770k and OC'd GTX670 pull 285w from the wall under max load or about 250w from the PSU.

My Q9300 OC to 3.0, and a HD4850 512MB card draw almost that much under full load. ~260W.

Power consumption, or performance/watt, has really come a long way.