Help with finding the appropriate PSU.

[sconr002]

Hello to everyone,

I am building my first desktop and learning a lot of great things, but I am being cautious with selecting the right PSU and I would be pleased to hear peoples feedback.

My current build (give or take) is listed below and I would like to keep the option open for having 2 GPUs

-Intel i7-4790k
-MSI Z97-GAMING 5 ATX LGA1150 Motherboard
-Gigabyte G1 Gaming GTX 970 4GB (Maybe SLi in the future)
-16GB (2 x 8GB) DDR3-2133 Memory
-120GB 2.5" SSD
-WD 1TB 3.5" 7200RPM Internal Hard Drive

I am seeing some similar builds with a 750W PSU. I would love to hear some feedback from this community, your forum here has helped me so much already. Thank you, Cheers!

 

[ronintexas]

If you are planning on SLI - the 750W PSU would be the minimum you want to get. Minimum recommended from Nvidia was 500W and each card would be 145W extra - putting you at 650W for basics....and 750W would give you a 100W cushion (I recommend at least 10% - in this case +65W = 715W - so 750W would be about right).

Make sure to get a solid PSU - Tier I or Tier II: http://www.tomshardware.com/answers/id-1925006/power-supply-tiered-list.html

 

[sconr002]

Thank you for the quick response ronintexas.

Would I be "okay" getting a 850W or around that range or would that be too much PSU, especially with only one GPU?

 

[ronintexas]

Getting a larger PSU results in wasted power (think of having up to a 100W light bulb just burning for no reason when your computer is on). Most of the better PSUs - especially the 80+ will waste less power. 750W should be more than enough unless you want to SLI 3 of those cards.

It will not hurt anything to get a higher wattage PSU.

 

[sconr002]

Another question, if I am doing a custom water cooling build will that require a higher wattage PSU? (My build will consist of (12) 120mm Fans, Pump, Water Blocker). I just don't want to cut myself short. So what I am understanding from the previous post is that if I go with the 850 Corsair Platinum, I will only waste power by consuming more power that will not get used. Does this sound correct? And if I am calculated to go with a 750 Watt PSU, I will not hurt my components and such by installing a 850 Watt PSU? Does this sound correct aswell? Thank you in advance, and sorry for the newbie questions.

 

[hunter315]

Getting a larger PSU results in wasted power (think of having up to a 100W light bulb just burning for no reason when your computer is on).

Thats not correct, a PSU only draws as much as it needs, and most of the 850W PSUs show similar efficiency to their 750W counterpart at the same load levels so the only thing an 850W PSU is wasting is money on the purchase price. I've done a write-up on efficiency myths before, both of you should give it a read, it should help clear up a bunch of your questions sconr002
http://www.tomshardware.com/forum/343495-28-power-supply-efficiency-myths

 

[ronintexas]

Thank you hunter315 for the info - very interesting read.

 

[hunter315]

Glad it helped! Modern power supplies are their own kind of beast and there is a lot of confusion and misinformation out there which doesn't help anyone.

@Sconr002, fans are pretty low power, the pump won't need a ton of power either. A good 650W PSU can run GTX 970 SLI, since you are adding some extra for the water cooling I'd recommend a 750W PSU which will also leave you some headroom to OC. Guru3D put a pair of 970s at needing 330W from the wall for themselves, their total system power draw with the CPU at full load would have come in about 550W so you would have lots of safety margin.
http://www.guru3d.com/articles_pages/geforce_gtx_970_sli_review,4.html