Power supply for 390x 390x X2

rossiboy001 · 11 Feb 2015 at 08:32

I know these cards are not out yet, but i guess they will be very similar to crossfire 290x and 290X2 requirements, but its easy to say just get a 1300 watt or so, but its the rails that Im unclear about, and dont want to end up spending a lot of money on one not suitable and blow things up. I have refrained from getting a 290xx2 or going crossfire this time round, i have kept the money aside, but in the meantime selling one of my 680"s and a few quid more on top, gives me about £200 spare to put back into a new PSU. This to replace my 750 watt, and i can pass that on to my son with the lightning i have. Therefore Im ready for when the new cards are available without having to do the tedious task of installing a new PSU at the time, and it gives me something to be getting on with too. So im looking for something that will be suitable for crossfire 390x or 2x390x dual card? Which cards should i be looking at?

pastymuncher · 11 Feb 2015 at 10:08

Nobody knows until they are launched. For all we know they may be even more power hungry than the current cards although hopefully not the case. Just wait and see.

sastusbulbas · 11 Feb 2015 at 22:53

Same boat here. I actually need a new PSU now as I only have 650w and two R7950 Twin FrozrIII for Crossfire, but plan on two highish end GPU's later this year, or two 290X or a 295x2 depending on costs, reviews, how 4k gaming goes when the AMD 300 series are reviewed.

The PSU calculators for a pair of 290X or single 295 X2 and AIO show 850w plus, with watercooling 1000w. I would hazard a guess at 1000W being adequate, with 1200w probably being OP but I doubt there would be any noticable difference in running costs considering the efficiency of gold/platinum Superflower/EVGA/Seasonic units?

I know that Custom PC pulled just over 1000w during their testing of three regular 290's in triple crossfire, with X99, an SSD and AIO system, during a 4k article.
Sort of suggests 1000W to 1300W for triple AMD GPU. I could be wrong, but surely the new 300 series cards are not going to draw 50% more power than a 290X?

rossiboy001 · 12 Feb 2015 at 07:32

Yes sastusbulbas. i was considering the superflower gold for about £150 its price yoyo"s as adequate, I think we are all clear about the power wattage, its just the rails cause that can make a difference, you can overload a PSU i guess by having the wrong configuration, i recall from watching videos for example the 2x290x has specific requirements.

jimhaumman · 12 Feb 2015 at 12:25

I just bought 1250W PSU Modular 80+ GOLD for 50 quid(second hand,still over 3 years warranty left).
Now I runnig crossfire hd7970 on 750W,which I never had problem with,but I'm getting ready for R390 crossfire in the future.