Am I right in thinking 850w?

Associate
Joined
26 May 2008
Posts
1,777
Hi all,

Over the next few months I am planning to re-house my 4770k Micro-ATX system, I had my mind set on a specific case but current doubts on cooling are having me ponder. I really want the Phanteks Mini XL, though it may be overkill.

Regardless, I had decided to stick with the 4770k Micro-ATX build, but feel the TJ08 case is limited and want a new case regardless.
The TJ08 has a 160mm PSU length limit, and I have a 2nd MSI 7950 sitting around, I want to use that in crossfire for a while, and would like to move toward higher resolution gaming in future.

Is 850w suited for two GPU's and an overclocked 4770k? I am undecided on air cooled GPU's with an AIO on the CPU, or a custom water loop for CPU and GPU's, possibly up to 4 hard drives, SSD's, and four to eight fans.
I would like the highest efficiency, but notice the price difference can be pretty small for an increase in PSU power. IE the 1000w is only £15 more roughly? I also want it as quiet as possible.

I had also thought of the Seasonic X-Series, but that model is a little long in tooth, and the Corsair 860i, though it seems poor value in comparison to EVGA though I am under the impression the Corsair is quieter and shorter in length.

Any opinions or review links would be appreciated, highest efficiency even at low loads and silence are important.
As is some form of future proofing I guess, I bought my current Seasonic X-Series PSU in 650w guise as I was sure I would not need more in it's life time, here it is still working away, and the 850w variant was less than the cost of a takeaway more back then.
 
Last edited:
A 620w but with two 7970?

It is for kit I already have, with more being added, and to be as efficient as possible, which usually means there is a specific mid point power draw that gives the optimum efficiency, my own Seasonic X-Series is 650w and fine with a single 7950 and i7 with a few hard drives, optic bay, fans and pci card, but I don't know how it would be with a water pump or two, more fans and HDD's and a second 7950 with higher overclocking.
 
Cheers Chug,

Thinking your right, still trying to think of excuses for 850w such as cost differences, future proofing, the stars and wind direction. I have used the Seasonic X-Series 650w psu since it came out, and it too has been more power than I needed for the single GPU systems it resided in. Yet here I am wishing I had just clicked on the 750w or 850w instead back then.

I had thought of EVGA due to the 10 yr guarantee, are the 750w/850w G2 EVGA's based on the Superflower design? I see they are slightly less efficient.

I also like the Seasonic Platinum + models. But again, £20 difference for 100w, basically a LED strip or evening in the pub.
And the 1000w and 860w are the same price in places. The efficiency is still around the same within the load limit I could be using, whether I run 750w or 1000w from what I can make out.
On top of that, the Seasonic 80 plus Platinum prices between 750w - 850w - 1000w can be as little as a takeaway. £146 for 750w, £168 for 860w, £150 for 1000w.

Originally I had the Corsair AX760i or AX860i in mind, as the budget was up to £160 for PSU.

When I had been contemplating a new full ATX X99 with two or three 290's I was looking at 1200w having seen other reviews and builds with 1200w and higher PSU's for three GPU's.

Remember I am still undecided regarding what the end system will be, but if I do watercool, it will probably be two 280 rads with push pull, two or three case fans, two SSD and possibly four HGST 4tb drives, one optic bay, LED lighting, 4770K on the Gene VI with up to four sticks of memory and whatever two GPU's will do decent frame rates at 4k later this year, so two Nvidia 970 or 980, or whatever AMD bring out, maybe even two 290 or 290X.

The two 7950's are only going to be getting me by until I get a new GPU or two this year and replace my monitor.

With some of the PSU calculators I use, when I input the possible end system and two 980's or two 290X, the recommended wattage jumps to 1200w in some cases, such as BeQuiet site.
 
I think the best advice I can give you is buy the best you can currently afford, at least if you do buy a quality unit from one of the aforementioned brands, it'll last for a long time, and give the certain element of future proofing I think you are looking for :)
 
Well I cannot seem to find a PSU calculator that shows less than 1000w as suitable for the future build I am thinking of progressing with through the year based on two 290X, as these may allow me to do 4K gaming at the lowest cost with my current system, and may drop in price when AMD release their new cards.

eXtreme Power Supply Calculator

1 cpu
4770K at 4.5 with 1.3 Vcore
4 modules of DDR3
1st card AMD Radeon R9 290X (or 390X)
2nd card AMD Radeon R9 290X (or 390X)
SSD 2 drives
7200rpm Sata 4 drives
BluRay BD-RE 1 drive
2 external USB hard drives (only picked two to cover my external Verbatim and WD drives, sometimes a phone, USB pen drive or such is also in there)
10 regular 140mm fans, though there would be 11.
1st pump a D5 vario
2nd pump a D5 vario (optional as it may not be in final build)

Calculates at 897w recommended with a 1000w EVGA suggested.

Of course, I may end up with less needed if newer AMD 390X series GPU's require less wattage, or if I have a single pump and run a NAS instead of drives, or may even end up with more hard drives and maybe a sound card or wireless PCI.

BeQuiet inputted specs,

CPU: Core i7-4770K
GPU: Radeon R9 290 X, Radeon R9 290 X
Drives: S-ATA 4x
RAM/Memory: 4x
Fans: 3x
Water cooling: 1x Pump, 3x Fan
Overclocked: yes

BeQuiet states 1018w maximum requirement, with a 1200w BeQuiet unit suggested?

Future proofing with the hopes of maintaining MicroATX can be headache inducing. The fall back if I cannot find a suitable two GPU rig for smooth 4k gaming could be three 290's and ATX. But even custom PC found their 4k test rig drew over 1000w with three 290's and an AIO cooled cpu, and only around 3fps difference between three way crossfire on X99 and Z97.

Maybe I should just stick my wee Gene VI in a 900D with a 2000w Superflower, I could probably fit in there with em and hide from the wife when she saw the electic bill 4K gaming may produce!
 
Still not decided on a power supply for this build project.

As I am hoping to get a decent 4k capable rig out of my Micro ATX 4770k system, with a watercooled set up and two 390X or equivalents. I have based my PSU calculator figures on the 290X because of what I have read here in these forums regarding the 390X GPU's. Of course power draw is therefor a guess, but nothing seems to indicate efficiency, if anything it looks like morewatts or the same ballpark as 290X.

As the GPU's are so close I think watercooling is the better cooling option. If Micro ATX does not work out, then I may end up going with an ATX system for three GPU's in future, but I am hoping next gen GPU's will be more capable than three 290's currently at 4k.

I get around 850w+ recommendations based on a reasonable overclock, two 290X and an AIO and less a few drives and such, but when I add watercooling pump and more fans that is when I get 1000w recommendations.
1000w is also what I see with many of the Custom builds inc Overclockers own with two 290X, and also popular with a single 295X2 GPU.

I am guessing 1200w is overkill, but if it's platinum or gold efficiency, is it going to cost any more to run? Because the price difference is not that huge. I really want it as quiet and efficient as possible, platinum preferred, budget of £200 give or take. The thing is, Superflower, EVGA, and Seasonic are near identical in tests apart from value, and I have not seen a clear indication of what is actually quieter.

So far from what I think I have seen, the Seasonic models are more efficient at idle and very low loads?

I am thinking of a system along these lines, as some of this I have.

4770K overclocked. Watercooled
Asus Z87 Gene VI
8gb of memory but I may move to 4x4gb
Two of the new 390X in crossfire, most likely overclocked. Watercooled.
1 256gb 840 Pro SSD
1 512gb MX100 SSD
1 to 4 HGST 7200rpm 4tb drives (all eventually going in server/nas)
1 BluRay optic read/write drive
3 140mm case fans
8 120mm radiator fans for push/pull depending on radiators
No idea about the pump thinking a D5 or two but have yet to research pumps and reservoirs, though I do like the idea of a combined pump top and res.

2 240mm rads at least, but the Mini XL has plenty of options here, looks like I could run a 360 in top and still have an optic bay, and a 240/280 on the rear while retaining the HDD bays, and later add a 240 in front when I move storage to Nas/Server.

1 CPU and 2 GPU blocks/backplates
LED strip
Phanteks Enthoo Mini XL case
Cablemods cable kit hopefully, depending on PSU.
But what PSU???

As much as I like the Superflower PSU's, those darn Cablemod sets knock them down a peg by not being compatable, how vain of me!
 
I bought XFX Pro Series 1250W Black Edition.
Ready for R 290X or r390X crossfire (depends on performance/pricing)
I asked the same question as you,how big psu operate on lower voltage.
According to reviews this psu has best energy efficance at 250W to 995W range (87%).
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story3&reid=273
Platinum is a gimmick,few % for that much extra cash???
Better get gtx 980 which is less power hungry then you cans see some savings in power draw.
 
Back
Top Bottom