850 Watts enough for 2 x GTX 970 ?

[reckless]

I am building a new rig. Wasn't sure about the PSU. Thinking of going with Corsair RM850 for 2 x Zotac GTX 970 (base model)
Is 850 Watts enough for 2 970s ?

The rest of the config is :

CPU - i5 4690
MB = ASUS H97 Plus
GPU - 2 x Zotac GTX 970
RAM - Gskill 8GB F3 12800Cl10S XL
HDD - 1 TB seagate
Cabinet - Cooler Master Fores 500
PSU - Corsair RM 850W
OS - WIn 7 64 bit

I primarily want to do Product animations. Also try archviz animations.
I want to build a super cost effective rig, and put the maximum investment into the GPUs.

[sikotik13]

That should be more than adequate for your system as listed. Also, you happen to have chosen a very good one, but your PSU should be just as important (arguably more so) as the GPUs , as it is required to make everything actually function. Just something to keep in mind when deciding upgrades and such.

[reckless]

Thanks for the quick response sikotik.
I was a little worried about Asrock as well. But haven't heard any negative reviews on it yet. should be alright.

[Pschelfh]

I have a GTX 970 + GTX 780 running on a 750W PSU, so no problem as 2x GTX 970 should consume less.

Peter.

[glimpse]

Your PSU is more than enough to lift up even couple of TitanXs..however..if You're serious 'bout archviz..& looking for long term investment better get something with slightly more vRAM at least.

why? we have out-of-core-texture functionality & so..why more vRAM? Well, You can save some space on Your GPUY with this useful feature but consider those facts:

* architect might ask You to render huge resolutions, that alone might eat up to 2GB of vram
* detailed car models might be in millions of poligons..
* trees & other greenery do have a lot of polies too, even if You are going to use instances few different species might put a load on Your vRam..

it's not a must though..You can always work with optimized models, lover resolutions (split rendering in few pieces), etc.. but it's always nice to have some headroom & don't have to think 'bout limitations..

Performance wise You get slightly less speed from something like TitanX compared to pair of 970s for way more 999$ versus 2x 350$..but..You get 3x of vRAM..

Just a though to consider =) not trying to sell here something..
..but a reason why GPU engines are not used so much in archviz..
is because of vram limitations - good this is fading out =)

P.S. pluss consider cost of upgrade-ability.. I mean if You would like to add more GPU power, You have to get rid one of Your cards..& in case of single TitanX You can always add one more =) so try to calculate long term costs, not only short term..

[smicha]

Glimpse is 101% right

Don't waste your money on 2x970 - get 1xTitanX.
Get better mobo for 4x dual slot graphics cards - you'll find great models for about 200-250$
Get 1200-1500W PSU

[reckless]

I did consider Titan X as well but it was pushing my budget by 30-40%. Plus I have been testing Octane on
my super slow Geforce GT 540M which has 2GB VRAM, and it is loading and rendering the product 3D models
just fine at HD resolution. (of course the render times are intolerable)
I tested one of the Evermotion car models aswell (800K polys), and it loaded and rendered fine. So I reckon a 3.5GB VRAM should also suffice.

I am primarily building this rig for jewelry animation.

Thanks for the detailed response Glimpse, I totally agree with you, a Titan X is definitely a better option. But I have reached the
limit of my budget with this rig. Hopefully I can afford the Titan X in the near future. And like you said, I will be selling
the 970s for 1 or 2(fingers crossed) Titan Xs in exchange (for archviz specially)

Smicha, What exactly do you mean by 4x dual slot graphics cards ? Some GPUs require dual x16 slots ?

Peter, could you please share the model number and other details of your PSU ? Thanks.

[smicha]

Smicha, What exactly do you mean by 4x dual slot graphics cards ? Some GPUs require dual x16 slots ?

Mobo that can handle four graphics cards, something like this:
http://www.gigabyte.com/products/produc ... id=4949#ov

[Pschelfh]

Peter, could you please share the model number and other details of your PSU ? Thanks.

I have a Coolermaster GX750.

Not considered to be great (efficiency 85%), but it's running fine for for a couple of years now.

I have all these things connected : i7 3770K, GTX970 (GTX760 before, which consumed more power), GTX780, 2 SSD's, 2 HDD's, 1 DVD, 1 Firewire (Steinberg MR816), 2 USB licenser keys, 1 USB midi keyboard, 1 USB3 HDD, 1 USB wireless device.

Peter.

[reckless]

Smicha. that looks mouth watering. Definitely something I would like to build next.

Peter. Thanks for the peripheral details.
I am definitely going with 750W now. Will get another 8gig RAM stick with the extra cash

What do you guys think of the Gainward GTX 970. Its 15% cheaper than the Zotac reference card.
I have never heard of this company before. But if there is nothing wrong with Gainward,
then I dont mind getting it. Use the extra cash on other parts.

Thanks again for all the help guys.