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Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 2:15 pm
by michael_d
I am planning to build an ultimate gaming rig sometime at the end of next year or sometime in 2015 when nVidia Maxwell architecture will be available in consumer products. I would like to get Ultra High Resolution monitor (hopefully they will be more affordable) with dual or may be even triple SLi setup.

In order to ensure that system is quiet and cool I would like to setup 2 power supplies:
-800/850 watt PSU for graphical subsystem.
-700/750 or less watt PSU for the rest of the system.

I know there are 2 good cases that have room for 2 PSUs, Corsair Obsidian 900D and Silverstone TJ11, there may be more.

I was wondering if anyone on this forum ever tried or has dual PSU setup and what potential disadvantages are except cost and case size.

Re: Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 2:40 pm
by kc77
Unless you are really going for something like Dual Sockets plus 3-way SLI and water cooling I don't see the need for dual PSU's. There are plenty of PSU's that can handle 3-way SLI and everything else. Something like this would work just fine.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817703012

At 1200w you aren't going to be short on power even with 3-way SLI.

Re: Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 3:23 pm
by DPete27
Yeah, you can run pretty much everything you can cram on a mobo with a 1200W PSU. Does the Corsair AX1200i meet the needs of your dream machine? Here's the TR Overview. If you're interested in letting your mouth drool and your wallet bleed, check out Anandtech's 4k gaming test results.

Re: Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 4:14 pm
by cynan
And in case those puny 1200W PSUs aren't enough, try

LEPA (Enermax) G1600-MA

Or some platinum efficiency rated ones:

ANTEC HCP-1300

Enermax Platimax 1350W

Seasonic is also coming out with a 1200W platinum rated PSU.. As others have already indicated, a well-regarded 1200W unit should prove enough power, even for 3-way Titans, an AMD FX-9590 and a couple of 18W pumps to water cool the whole deal. While it may be rated at 1200W, a good unit will put out at least 10% more than the rated maximum without having efficiency drop off too terribly.

If you can configure a single CPU three-way SLI system (that doesn't include anything out of the ordinary like a pull-out space heater, clothes iron or hair dryer) that any of the ones linked to in this post prove insufficient to power, then I'll buy you a second one :D

Edit: If you really think you might need 1500W or more out of a single PSU, you'd better make sure to have a 20A circuit installed just in case.

Re: Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 4:48 pm
by michael_d
Thanks for all replies.

I am aware that 1200W PSU is enough for Tri-SLi. I just think that 2 separate PSUs 700/800 Watts will be quieter and cooler. Judging by the results from Anandtech I believe when Titan 2 based on Maxwell comes out dual SLi should be enough for 3820x2160.

Re: Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 5:03 pm
by cynan
I would tend to think that in most cases, dual PSUs in the place of a single efficient high current unit would produce more heat and be less efficient if anything. But the bottom line is that it will probably cost you at least $100 more for the case and the PSUs by going the dual root, and I can't really see how you're benefiting. I have a Seasonic-based gold-rated 1050W PSU in my gaming PC and that thing is as silent as I could want. I'm sure the many of the 1200-1300W equivalents are just as silent. The other thing you may get by going with a single high-end PSU is more features (ie, such as with the Corsair version linked above that comes with monitoring software, etc).

And if you don't use ridiculous image quality settings I think you'd get by exceptionally well in 99% of games coming out over the next couple of years with dual Titans or even GTX 780s at 4k (although the extra memory on the Titans vs the 780s may help in certain cases)

Re: Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 5:51 pm
by michael_d
cynan wrote:
I would tend to think that in most cases, dual PSUs in the place of a single efficient high current unit would produce more heat and be less efficient if anything. But the bottom line is that it will probably cost you at least $100 more for the case and the PSUs by going the dual root, and I can't really see how you're benefiting. I have a Seasonic-based gold-rated 1050W PSU in my gaming PC and that thing is as silent as I could want. I'm sure the many of the 1200-1300W equivalents are just as silent. The other thing you may get by going with a single high-end PSU is more features (ie, such as with the Corsair version linked above that comes with monitoring software, etc).

And if you don't use ridiculous image quality settings I think you'd get by exceptionally well in 99% of games coming out over the next couple of years with dual Titans or even GTX 780s at 4k (although the extra memory on the Titans vs the 780s may help in certain cases)


I do use ridiculous image quality settings :D that's why I bought Titan. I was referring to high quality platinum rated 700/800 Watt Seasonic/Corsair PSUs. My idea is to have each of the 2 PSU run at about 40% or less of their total capacity rather than single PSU run at 60% or more.

Re: Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 6:29 pm
by juzz86
michael_d wrote:
cynan wrote:
I would tend to think that in most cases, dual PSUs in the place of a single efficient high current unit would produce more heat and be less efficient if anything. But the bottom line is that it will probably cost you at least $100 more for the case and the PSUs by going the dual root, and I can't really see how you're benefiting. I have a Seasonic-based gold-rated 1050W PSU in my gaming PC and that thing is as silent as I could want. I'm sure the many of the 1200-1300W equivalents are just as silent. The other thing you may get by going with a single high-end PSU is more features (ie, such as with the Corsair version linked above that comes with monitoring software, etc).

And if you don't use ridiculous image quality settings I think you'd get by exceptionally well in 99% of games coming out over the next couple of years with dual Titans or even GTX 780s at 4k (although the extra memory on the Titans vs the 780s may help in certain cases)


I do use ridiculous image quality settings :D that's why I bought Titan. I was referring to high quality platinum rated 700/800 Watt Seasonic/Corsair PSUs. My idea is to have each of the 2 PSU run at about 40% or less of their total capacity rather than single PSU run at 60% or more.


Well, you could probably get away with downsizing the non-GPU PSU a bit. Just looking back through old reviews, seems about 150-200W is a fair figure for required system power minus GPU power. That means you'll want a 300-400W PSU for maximum efficiency there.

I have seen nothing about Maxwell, but I'd think a good guess for a beefy, Titan-esque single-GPU on a newly-refined, lower lithography architecture would be about the 300W mark, perhaps even 250W like Titan, just cramming more efficiency into the same envelope. That'd mean a 500-600W PSU for double, and 750-900W PSU for triple SLI.

Looking at these, it seems that dual PSUs - although cool - would indeed be a bit of a waste. If we go with 150W for SYS and 500W for GPU, that's right at the max. efficiency of a 1200 or 1300W unit. Having a PSU underloaded doesn't improve efficiency, unfortunately :) Save the cash and put it towards a PCI-E SSD instead ;)

Also. As a fellow 30-inch panel owner with a Titan, how are you finding it? I went with a 690, just interested in hearing some of your framerates and settings, as I'm a huge sucker for AA and PostFX too :)

Re: Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 6:32 pm
by Airmantharp
juzz86 wrote:
Also. As a fellow 30-inch panel owner with a Titan, how are you finding it? I went with a 690, just interested in hearing some of your framerates and settings, as I'm a huge sucker for AA and PostFX too :)


My GTX670's still aren't fast enough for my 30" :). They'll certainly hold me over until I get around to using 4k on the desktop though!

Re: Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 7:19 pm
by michael_d
juzz86 wrote:
michael_d wrote:
cynan wrote:
I would tend to think that in most cases, dual PSUs in the place of a single efficient high current unit would produce more heat and be less efficient if anything. But the bottom line is that it will probably cost you at least $100 more for the case and the PSUs by going the dual root, and I can't really see how you're benefiting. I have a Seasonic-based gold-rated 1050W PSU in my gaming PC and that thing is as silent as I could want. I'm sure the many of the 1200-1300W equivalents are just as silent. The other thing you may get by going with a single high-end PSU is more features (ie, such as with the Corsair version linked above that comes with monitoring software, etc).

And if you don't use ridiculous image quality settings I think you'd get by exceptionally well in 99% of games coming out over the next couple of years with dual Titans or even GTX 780s at 4k (although the extra memory on the Titans vs the 780s may help in certain cases)


I do use ridiculous image quality settings :D that's why I bought Titan. I was referring to high quality platinum rated 700/800 Watt Seasonic/Corsair PSUs. My idea is to have each of the 2 PSU run at about 40% or less of their total capacity rather than single PSU run at 60% or more.


Well, you could probably get away with downsizing the non-GPU PSU a bit. Just looking back through old reviews, seems about 150-200W is a fair figure for required system power minus GPU power. That means you'll want a 300-400W PSU for maximum efficiency there.

I have seen nothing about Maxwell, but I'd think a good guess for a beefy, Titan-esque single-GPU on a newly-refined, lower lithography architecture would be about the 300W mark, perhaps even 250W like Titan, just cramming more efficiency into the same envelope. That'd mean a 500-600W PSU for double, and 750-900W PSU for triple SLI.

Looking at these, it seems that dual PSUs - although cool - would indeed be a bit of a waste. If we go with 150W for SYS and 500W for GPU, that's right at the max. efficiency of a 1200 or 1300W unit. Having a PSU underloaded doesn't improve efficiency, unfortunately :) Save the cash and put it towards a PCI-E SSD instead ;)

Also. As a fellow 30-inch panel owner with a Titan, how are you finding it? I went with a 690, just interested in hearing some of your framerates and settings, as I'm a huge sucker for AA and PostFX too :)


I always go with E-series CPUs which is at least 130W, plus other components including PCI-E sound card, I think that 300-400W PSU is not enough to stay below 40% usage. I would say at least 550W but if price difference is negligible why not 700W. The amount of money you can save by purchasing lower wattage PSU is not going to be enough for PCI-E SSD those things are darn expensive. Besides PCI-E SSD have not been out long enough to determine their real world lifespan and stability of firmware. However, by the time I am ready for my next upgrade hopefully they will come around.

Here is a little article on Maxwell.

It has been just over 3 weeks since I upgraded from Sapphire HD7970 to ASUS GTX Titan and it is like day and night at 2560x1600 with AA because game play is so much smoother. Titan delivers twice the performance of HD7970 when AA is enabled. So far I played STALKER CoP with high resolution textures mod, Metro 2033 and Last Light, Rage and Crysis. I do not have exact frame rates but Titan performs really well in all games with all in-game settings set to maximum. Crysis at 8AA no problem, Rage with custom config at 8AA no problem, Metro 2033 MSAA x4 no problem. The only problem is to run Metro Last Light at SSAA x4 it is playable but feels a little choppy, hopefully newer drivers will increase performance.

I would like to try Crysis 3 but it is still not cheap enough for my liking. I have never been a big fan of any of the "Cry" games I only buy them at bargain prices. Benchmarks indicate that Crysis 3 is less demanding than Metro Last Light so I do not expect any issues.

Re: Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 7:42 pm
by Airmantharp
Check the FS/FT forum over at the [H]. I bought four of the latest games from people selling the AMD codes for under $60 total.

Re: Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 7:43 pm
by DeadOfKnight
Airmantharp wrote:
juzz86 wrote:
Also. As a fellow 30-inch panel owner with a Titan, how are you finding it? I went with a 690, just interested in hearing some of your framerates and settings, as I'm a huge sucker for AA and PostFX too :)


My GTX670's still aren't fast enough for my 30" :). They'll certainly hold me over until I get around to using 4k on the desktop though!

How are dual 670s not good enough at that resolution? You should be able to max everything out and still get over 30fps. Maybe you'll have to dial back the AA a bit, but anything over 2xSSAA or 4xMSAA would be overkill at that resolution.

Re: Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 7:48 pm
by Airmantharp
It's BF3, mostly- cranking the settings there (or default Ultra) results in too much choppiness; and hell, even at 4.6GHz, the 2500k is taxed; it was more taxed for the few months I was at 1920x1200, though. That game needs everything you can give it and more.

I do have a stack of single-player games to go through- just really haven't had the interest. BF3 is a community thing, and that's the only part of it keeping me there; otherwise, I'd rather be playing with my camera :).

Re: Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 8:23 pm
by juzz86
michael_d wrote:
I always go with E-series CPUs which is at least 130W, plus other components including PCI-E sound card, I think that 300-400W PSU is not enough to stay below 40% usage. I would say at least 550W but if price difference is negligible why not 700W. The amount of money you can save by purchasing lower wattage PSU is not going to be enough for PCI-E SSD those things are darn expensive. Besides PCI-E SSD have not been out long enough to determine their real world lifespan and stability of firmware. However, by the time I am ready for my next upgrade hopefully they will come around.

Here is a little article on Maxwell.

It has been just over 3 weeks since I upgraded from Sapphire HD7970 to ASUS GTX Titan and it is like day and night at 2560x1600 with AA because game play is so much smoother. Titan delivers twice the performance of HD7970 when AA is enabled. So far I played STALKER CoP with high resolution textures mod, Metro 2033 and Last Light, Rage and Crysis. I do not have exact frame rates but Titan performs really well in all games with all in-game settings set to maximum. Crysis at 8AA no problem, Rage with custom config at 8AA no problem, Metro 2033 MSAA x4 no problem. The only problem is to run Metro Last Light at SSAA x4 it is playable but feels a little choppy, hopefully newer drivers will increase performance.

I would like to try Crysis 3 but it is still not cheap enough for my liking. I have never been a big fan of any of the "Cry" games I only buy them at bargain prices. Benchmarks indicate that Crysis 3 is less demanding than Metro Last Light so I do not expect any issues.


I agree on Crysis - never been a huge fan personally, but always have a quick play once they drop in price. If you're running E-class then yeah, my SYS PSU requirement is way under-spec, lol. But, if you're running E-class just for games, there's a legit argument that you're wasting a lot of potential (and money), and not even seeing the best performance you could be with a K-class etc. I'm not privy to your workload, but you did say 'ultimate gaming rig', so I assume it's going to be mostly gaming. The idea is to chase 50% PSU capacity, regardless of what you run. This may or may not be the same on 110V in the US, as I'm on 240 :)

I must say, I agree on the graphics. I picked up the GTX690 cheap to replace a HD6990, and have been nothing but impressed by it. I'm consistently hitting vsync with everything on from Civ V and ANNO 2070 to FarCry 3 and Metro, and I love it. Admittedly, I do dial back AA until I can see a difference, so I usually end up running at about 4x and then delegating the rest of the GPU power on PostFX or something else.

AMT - your 670s should be giving you very close to what I'm getting - sucker for AA too mate? Haha ;)

Re: Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 9:17 pm
by DeadOfKnight
juzz86 wrote:
AMT - your 670s should be giving you very close to what I'm getting - sucker for AA too mate? Haha ;)

Actually, I dunno if he's got 4GB 670s, but if so he should be getting even better than you with everything cranked up at 2560x1600.

If shopping for video cards right now to run at that resolution, I'd say 2x 770 4GB is the sweet spot for eye candy (pun not intended).

Granted, a 780 is going to be better for games that don't scale well with SLI, but that doesn't seem to be as big an issue nowadays.

Re: Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 10:00 pm
by Airmantharp
Well, they're 2GB cards (I'll consider 8GB cards for 4k when that comes around), which is perfect for 1600p; and they're definitely overkill for most things. But my 'most things' is BF3, and that's where I really want the performance- and I don't run any AA, just FXAA Medium. Aliasing bothers me less than missing the shot :D.

Re: Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 10:09 pm
by juzz86
DeadOfKnight wrote:
Actually, I dunno if he's got 4GB 670s, but if so he should be getting even better than you with everything cranked up at 2560x1600.

If shopping for video cards right now to run at that resolution, I'd say 2x 770 4GB is the sweet spot for eye candy (pun not intended).

Granted, a 780 is going to be better for games that don't scale well with SLI, but that doesn't seem to be as big an issue nowadays.


Agree on both counts. Completely forgot there was a 4GB 670, didn't see many of those over here, and those that did pop up had a premium to match. As is usually the way in Australia.

I can't really speak about improvements nVidia have made as such, but the jump in fluidity from the HD6990 to the GTX690 was leaps and bounds, personally. Framerate plays a big part in some games no doubt, but even on games where they both hit vsync, the GTX690 echoes Scott's review in being noticeably smoother all-round - nVidia's frame metering steps are obviously helping a lot. I hope the improvements AMD are making to their drivers will roll back and help out the older cards, especially the CFX-on-a-stick ones :) It's taken a long time, but it's good to see multi-GPU getting some much-deserved attention now that increasing resolutions (and eye-candy) are increasing uptake. It's also no longer so cost-prohibitive to own two cards, especially as two mid-fielders can give top-line performance for less money these days.

Re: Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 10:25 pm
by Airmantharp
I came from a pair of HD6950's with 2GB each- and even a single GTX670 was far smoother. The AMD setup posted the frames, sure, but they were meaningless.

Re: Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 10:40 pm
by juzz86
Airmantharp wrote:
I came from a pair of HD6950's with 2GB each- and even a single GTX670 was far smoother. The AMD setup posted the frames, sure, but they were meaningless.


I always wondered what the straight comparison to two 6950s with a 6990 would look like, but was never able to find an article or even forum posts on it (didn't look too hard, admittedly - sour grapes and all that). Whether there is actually even a slight benefit to having all the inter-GPU comms onboard, or whether the cable makes bugger-all difference. I've always been a "If I'm having two GPUs, they're staying on one board" kinda fella - and since the 4870X2 they've treated me pretty well :) I stepped up to the 6990 from a (single) GTX570 funnily enough - I'd been out of work with a redundancy, and had to part with the GTX295 I had before then for some spare money. Thankfully, times are better now :)

PS: Happy 4,000! :)

Re: Dual PSU setup for ultimate gaming rig

Posted: Tue Jul 09, 2013 10:46 pm
by Airmantharp
Thanks, you know I've been here too long. And funnily enough, I traded my GTX570SC straight for the first HD6950 (1.25GB of RAM just doesn't cut it at 1600p). The GTX570 was a nicer card for sure.

Re: Dual PSU setup for ultimate gaming rig

Posted: Wed Jul 10, 2013 6:02 pm
by juzz86
Airmantharp wrote:
Thanks, you know I've been here too long. And funnily enough, I traded my GTX570SC straight for the first HD6950 (1.25GB of RAM just doesn't cut it at 1600p). The GTX570 was a nicer card for sure.


Skyrim was my big thing at the time, and it held its own pretty well, although it certainly wasn't maxed out. I remember on the 570, campfires and braziers wouldn't show flames for me. I got the 6990, saw flames and got so excited, haha!

I see a ton of people here with high post counts. That usually points to a pretty cool place to hang out - as opposed to a forum full of low-count members asking questions and posting rubbish, the high-post guys frequent, make most of the threads and are generally very helpful. I've read TR since about 2008 but only recently registered to post a few comments on articles, etc. I enjoy it here, mainly because it's usually proper technical conversation :) So nah, I don't think 'way too long' is right, haha ;)

Re: Dual PSU setup for ultimate gaming rig

Posted: Fri Jul 12, 2013 4:26 pm
by DeadOfKnight
Airmantharp wrote:
Thanks, you know I've been here too long. And funnily enough, I traded my GTX570SC straight for the first HD6950 (1.25GB of RAM just doesn't cut it at 1600p). The GTX570 was a nicer card for sure.

Check this out: http://www.youtube.com/watch?v=PSHrcAWS2C8

Re: Dual PSU setup for ultimate gaming rig

Posted: Sun Jan 05, 2014 4:30 pm
by klepp0906
michael_d wrote:
Thanks for all replies.

I am aware that 1200W PSU is enough for Tri-SLi. I just think that 2 separate PSUs 700/800 Watts will be quieter and cooler. Judging by the results from Anandtech I believe when Titan 2 based on Maxwell comes out dual SLi should be enough for 3820x2160.


Unfortunately their won't be a titan 2. Titan was a one off and didn't do well enough for them to incorporate them as the replacement flagship.

However to add to the thread, I'd consider going with dual 1k psus. The price you can get them at these days is awesome and too much is > not enough. Psus run best at half load anyhow.

To those who are still adamant about a 1200 being enough for tri titan ... Consider this. I am running dual 1500w psus in my quad titan rig and the one on my system hits about 600 while gaming and my titan psu hits about 1200 while gaming. That's with only the cards on it. If I hook my rig up it will just shut down. While benchmarking I can shut it down anyhow so please err on the side of caution especially if you intend to overclock. I'm not even under water yet on the cards and I peak at 2600w from the wall while benching. The evga G2s are sick good. Gold, 10yr warranty, 150 bucks. Amazing value.

Re: Dual PSU setup for ultimate gaming rig

Posted: Sun Jan 05, 2014 4:39 pm
by Deanjo
klepp0906 wrote:
Titan was a one off and didn't do well enough for them to incorporate them as the replacement flagship.


Umm, they sold every one that they could offer for months. Titan did and still is doing very well although it did lose the gamers to the 780Ti when it came out but for GPGPU gurus it is still very much in high demand.

Re: Dual PSU setup for ultimate gaming rig

Posted: Sun Jan 05, 2014 7:36 pm
by michael_d
klepp0906 wrote:
michael_d wrote:
Thanks for all replies.

I am aware that 1200W PSU is enough for Tri-SLi. I just think that 2 separate PSUs 700/800 Watts will be quieter and cooler. Judging by the results from Anandtech I believe when Titan 2 based on Maxwell comes out dual SLi should be enough for 3820x2160.


Unfortunately their won't be a titan 2. Titan was a one off and didn't do well enough for them to incorporate them as the replacement flagship.

However to add to the thread, I'd consider going with dual 1k psus. The price you can get them at these days is awesome and too much is > not enough. Psus run best at half load anyhow.

To those who are still adamant about a 1200 being enough for tri titan ... Consider this. I am running dual 1500w psus in my quad titan rig and the one on my system hits about 600 while gaming and my titan psu hits about 1200 while gaming. That's with only the cards on it. If I hook my rig up it will just shut down. While benchmarking I can shut it down anyhow so please err on the side of caution especially if you intend to overclock. I'm not even under water yet on the cards and I peak at 2600w from the wall while benching. The evga G2s are sick good. Gold, 10yr warranty, 150 bucks. Amazing value.


Quad Titan :o !!!??? What is SLi scaling like? Dual, Tri and Quad.