Power for Crossfire 290x

[SleepyTomato]

Is the Corsair HX850i enough to power the system below? I was allocating 300w to each of the 290x cards, but it seems they can peak at close to 400w each, and that the 8GB cards consume a bit more than the 4GB versions, so I'm beginning to question whether the PSU can handle the system load.

Specs:
i5-6600k
2x 8GB XFX 290x
32 GB 2800 DD4
512 GB Crucial BX100
2 TB HDD
Blu-ray writer
Wireless card

I won't be overclocking/overvolting at all.

PSU: http://www.newegg.com/Product/Product.aspx?Item=N82E16817139083
Graphics cards: http://www.newegg.com/Product/Product.aspx?Item=N82E16814150723

 

[Arcanedeath]

It's pushing it on only 850 watts, even at stock speed, but if you power limit the 290Xs to the appropriate amount it should work fine.

 

[MrTeal]

Is the Corsair HX850i enough to power the system below? I was allocating 300w to each of the 290x cards, but it seems they can peak at close to 400w each, and that the 8GB cards consume a bit more than the 4GB versions, so I'm beginning to question whether the PSU can handle the system load.

Specs:
i5-6600k
2x 8GB XFX 290x
32 GB 2800 DD4
512 GB Crucial BX100
2 TB HDD
Blu-ray writer
Wireless card

I won't be overclocking/overvolting at all.

PSU: http://www.newegg.com/Product/Product.aspx?Item=N82E16817139083
Graphics cards: http://www.newegg.com/Product/Product.aspx?Item=N82E16814150723

I run the system in my sig pretty highly overclocked, and it can pull 900W at the wall, so maybe 830W DC. That's a completely unrealistic load though, with a highly OC'd hex core running P95 w/AVX and overclocked and overvolted 290s running Furmark. It also includes ~75W DC of fans and pump.

At stock speeds you should be fine even running power viruses. In gaming loads, even a 850W supply should have a decent bit of overhead.

 

[SleepyTomato]

Here's the review that makes me worry:
http://www.tomshardware.com/reviews/radeon-r9-290-and-290x,3728-4.html

Some of their 290x cards are OCed, but they're also 4GB cards, so I figure their maxes should be close to mine. Any idea on how much power is consumed by the extra 4GB VRAM? Also, are 390x cards more efficient somehow? One of the power calculators said my system would draw 100 W less if I replaced each of my cards with a 390x.

 

[MrTeal]

Here's the review that makes me worry:
http://www.tomshardware.com/reviews/radeon-r9-290-and-290x,3728-4.html

Some of their 290x cards are OCed, but they're also 4GB cards, so I figure their maxes should be close to mine. Any idea on how much power is consumed by the extra 4GB VRAM? Also, are 390x cards more efficient somehow? One of the power calculators said my system would draw 100 W less if I replaced each of my cards with a 290x.

The higher capacity RAM won't have a very large increase in power consumption, barring better performance of course. Tom's measured an OC'd 8GB Vapour-X pulling 33W more than a reference 4GB 290X. Definitely nothing like the couple hundred extra watts I see running at +100mV and 1150.

 

[SleepyTomato]

Thanks for the input MrTeal. I definitely think my rig should be okay for the most part - I'm confident that the PSU can handle the typical load just fine. What worries me are the max power peaks in the review I linked to - they would probably push my system to ~100W above my PSU's rated capacity if they occur on both cards simultaneously. Not sure how likely that is, or how big of an issue given they last only for a short moment, but I'd rather not find out the hard way.

 

[UaVaj]

Here's the review that makes me worry:
http://www.tomshardware.com/reviews/radeon-r9-290-and-290x,3728-4.html

Some of their 290x cards are OCed, but they're also 4GB cards, so I figure their maxes should be close to mine. Any idea on how much power is consumed by the extra 4GB VRAM? Also, are 390x cards more efficient somehow? One of the power calculators said my system would draw 100 W less if I replaced each of my cards with a 290x.

with 850w. you should be worry. especially if you care about uninterrupted gaming. if you can live with some interruptions. no need to read below.


390x is essentially a 290x oc with more ram. power consumption will be identical at same clocks. 4gb extra vram at same clock will add a little more watts. insignificant in overall comparison.

have four 290x reference. all stock uber bios setting with custom fan curve via asus tweak. so absolutely no throttling whatsoever. typically it is ~85c and ~65% fan in 27c ambient.

these gpu are power hungry. with a gaming load. once in a blue moon it will successfully trip a 30a ocp rail. typical 12v voltage during gaming load is ~11.8v. that means it is "peaking" beyond 354 watts.

for sure a 390x / 290x oc will draw more watts than a 290x reference - as tom has proven. you definitely want ~400watt power reserve per gpu to ensure you are fully covered incase of peaks.

 

[Actaeon]

You have more accessories than I do, but I ran 2x 290Xs in Crossfire on an Corsair AX850 without any problems. Never had any problems with stability even when overclocked. I was maxing out my display's resolution and refresh rate at the time so I didn't need them overclocked anymore and actually underclocked them to keep them nice and cool. I had a 2600K @ 4.5ghz and one 2.5GB HDD plugged in. Occasionally I'd plug in an external HDD or DVD drive via USB but not while playing a game. Anyway, I had no problems at all with a 850W.

http://www.guru3d.com/articles-pages/radeon-r9-290x-crossfire-vs-sli-review-benchmarks,4.html

This page says it'll draw 551W from the GPUs alone. With 850W you have 300 for the rest of the system which seems fine to me.

 

[gradoman]

I also ran R9 290 in crossfire with an AX850i. It was fine.

4790k/Z97/4 hard drives, 1 SSD, 6 fans, etc.