Multiple Video Cards

Almost nobody should do what I am about to describe – that is, install and use more than one video card. Nobody really needs that much graphics performance. It's also technically complex and a little expensive. But sometimes you gotta say to hell with rationality and embrace the overkill.

This is a companion discussion topic for the original blog entry at:

You still running this on Vista?

Never been a fan of running two power hungry GPUs in parallel. I love to game and spend 2-3 hours a day playing games but the excessive power usage just isn’t worth it for me. I’ll keep playing BF3 at 1080p 45fps that my current i5-2500k, GTX460 system does.

What 27" monitor do you have?

old, single ATI 5870 power results (4.4 Ghz CPU)

Idle at Windows desktop: 128w (multiple monitors)
Prime95 full load: 255w
video stress (game): 210w
Prime95 + video: 332w

new, dual ATI 5870 results (4.0 Ghz CPU)

Idle at Windows desktop: 120w (single monitor) 136w (multiple monitors)
Prime95 full load: 215w
video stress (game): ~400w
video stress (furmark): ~530w (!!)
Prime95 + furmark: ~620w (!!)

Not exactly apples to apples since I lowered the overclock of the i7-2600k CPU a bit to compensate. We have obscene amounts of CPU power anyway, that’s not even remotely the bottleneck in any current or new game. But, almost exactly a doubling of power consumption when gaming, which I guess isn’t unexpected. That furmark thing is a monster, though. Really scary. No game loads the system as much as that damn synthetic benchmark does.

Some typical gaming numbers. I played a bit of Bulletstorm at max settings, 2048x1152 and got:

  • CPU temp max 59c
  • GPU temp max 64c, fan duty 49%

That’s without turning the fan knob up at all. To be fair, Battlefield 3 loads it maybe 2x as much as this, but there’s still a TON of headroom with the fan knob turned up.

With prime95 + furmark – which I consider to be utterly absurd but a good representative of the “you will never ever see it this bad in real life” absolute crazy possible maximum:

  • CPU temp 76c
  • GPU temp 84c, fan duty 86%

I don’t like running this test for too long because it’s … ridiculous, but it does trend toward stabilization at about those numbers. Note that the video card fans don’t even get to 100% which indicates the cards are not totally stressed, temperature wise, even in the dumb furmark case.

Out of curiosity, does your case fit the Corsair H100 with push/pull fans without mods? I’ve been considering getting the 600T

For all your obsessive chasing of the latest and greatest, I’m surprised to see you still using internal drive bays.

Swappable hard-drives makes loads of things a whole lot easier.

Some problems creep up when using a mini-ITX build: you can have only one card. But thanks to some good cases and video card manufacturer, the GTX590 can come to the rescue.

Another BF fan since 1942 here! :slight_smile:
I just got a GTX570 for BF3, the beta ran great for me. At 1980x1200 4xAA with High settings I got around 45 FPS. When the game is released I’ll tweak the settings and try to get a stable 60 FPS without sacrificing graphics, often it’s the most subtle effects that are the most demanding.

In multiplayer games like BF3 though you might sometimes want to run lower settings even if your machine could handle higher, because all those effects can obscure your view and make it harder to spot enemies. In BF: Vietnam, there was a lot of high grass to hide in, but if you turned the settings down the grass would disappear, rendering hiding enemies visible.

@jdege How in the name of god do you compare swappable hard drive bays to the latest and greatest? Why would you even need swappable hard drive bays? Nowadays, hard drives are so absurdly large (with the notable exception of SSDs), that you could fit any OS you could possible hope to use on a single hard drive.

“Why would you even need swappable hard drive bays?”

Backups. Multiple OSes. Experimentation.

It’s a lot easier to install Windows and Linux on separate drives, and to swap the drives, than to keep them working together in a dual boot.

Right now I’m in the process of trying out Ubuntu 11.10. So I’ve made a copy of my Ubunto 10.04 disk, booted from it, and am currently running Ubuntu’s upgrade process. If something goes wrong, it’s easy enough to swap back to the original.

Like you said, HDs are cheap, these days. Enough so that having a bunch of them is quite reasonable. And being able to swap them in and out without having to crack the case is a major convenience.

I’m surprised this post came out specifically for BF3. At 1080p I ran the game on Ultra and had no problem with 60FPS even on Caspian with a ton of crap going on.

My setup is (all timings are stock, no o.c.):

i7 2600k
Radeon 6950
16GB pc1600

Resolution is set at 1920x1080.

I think for most people SLI/Xfire for BF3 alone would not be needed. This should only be necessary if you’re running a crazy resolution…say 2560 x 1600. If you look at the latest Steam survey, less than 1% have better than 1900 resolution.

People were doing multiple video cards a long time ago with 3DFX cards. Back then, SLI stood for Scan Line Interleave. Instead of interleaving frames, they would interleave individual lines of the same frame. Amazing how little things change.

jdege said:
It’s a lot easier to install Windows and Linux on separate drives, and to swap the drives, than to keep them working together in a dual boot.

It isn’t hard at all. Even if you re-install Windows, it takes all of two minutes to boot from the Linux install disc and put GRUB back in the MBR. Swapping drives is unnecessary mechanical wear-and-tear. It’s like stopping to physically replace the gearbox in your car because it’s too hard to push in the clutch and move the stick to switch gears.

“It isn’t hard at all.”

If it’s just dual-booting a Windows and a Linux installation, perhaps. But how many versions of Windows do you have? Of Linux?

When you upgrade from Windows 7 to Windows 8, will you do it on your live system, or on a copy? If you do it on your live system, how long will it take to restore from backup, after something goes wrong?

For that matter, how long has been since you restored to a bare drive from your backups? If you’ve never done so, how do you know your backups are actually working?

“Swapping drives is unnecessary mechanical wear-and-tear.”

Drives are cheap.


I’m really surprised that you are supporting Battlefield 3 after they announced that it would not be available on steam. This sounds exactly like the type of thing you would be against. If you haven’t heard of this issue, I highly recommend you do some research.

The basic facts are:

Battlefield 3 won’t be available on steam. In fact, EA has been pulling a number of games off steam.

EA is pushing the use of their own download manager. This download manager is terrible, it doesn’t handle any of the DLC, patching, keys, or installation. The user still has to do that on their own.

EA has a terrible track record with DRM. Remember SecureRom? Thousands of users were unable to play games they legally purchased because of faulty DRM schemes. This has happened more than once on EA titles.

EA has stated that they will remove your ability to re-download you have purchased 1 year after the purchase date (unless you pay extra for “re-download insurance”).

EA has stated that they will delete your account (and your license to all content purchased under that account) after 2 years of inactivity.

This is a giant step backwards for the gaming community.

I lost hundreds of hours to Battlefield 2 and Battlefield: Bad Company 2.

Forget the tech, I want to know how you find time to do games and still get so much done, dang.

I just bought a Radeon 6870 and that low 37.3 benchmark score makes me think I should take it back and get something else.

Any advice from the gallery? I need to stay under $200 total.

“I just bought a Radeon 6870 and that low 37.3 benchmark score makes me think I should take it back and get something else.”

Look at the benchmark. 2560x1600 with max settings and 4xAA. If you’re going to run that resolution with max settings then yes you will want a new card. If you’re running 1920x1080 or 1600x900 you’ll probably be ok. Also, some of the settings are redundant at higher resolutions. The higher the resolution, the less AA you need. The difference in 8x AA and no AA at 2560x1600 is much less noticeable than the same comparison at 1440x900.

"I just bought a Radeon 6870 and that low 37.3 benchmark score makes me think I should take it back and get something else. "

The 6870 is no slouch. If you look at the chart this is at 2560x1600 resolution with max settings. I doubt if you are on a budget you have a monitor at that resolution.

Also the chart is mainly SLI/CF configurations. The GTX 580 is the fastest single card for this particular game and still only manages 57 fps.

If you feel you must get a better card I would look at a HD6950 these have the same hardware as a HD6970. A firmware modification can swap it for you and unlock the extra processing free of charge. Nice little trick.