Performance hit per monitor?

[Pragmata]

Hi everyone,

I have been trying to get some numbers on this, but can't find a whole lot. What kind of performance hit does adding a monitor to a gpu have? Let's say you are gaming on one monitor at 1920x1080 and you add a second monitor. How does that impact performance by the numbers (fps, percentages). Not to game on the other monitor or do any special crossfire setup, but just there working. Showing you a desktop. Any thoughts?

To give some cards to work with, a 7850 can power through BF3 1920x1080 maxed at ~30FPS (acceptable in my books). If I add in a second monitor (still playing on only one) what kind of fps drop would you be looking at? A 7950 can do the same game at ~40FPS on max everything. Is that enough to offset more monitors? Is it just a matter of VRAM?

Thanks!

 

[FtsArTek]

If I run a second 1080p monitor without playing a game on it I get less than 5fps frame drop ( i normally get 90+ in BF3). And a third one again. If I play BF3 over all three I get 40fps+ with drops depending where I am. So you shouldn't notice anything. The less the FPS I get in the game, the less the drop is from the other monitors.

With a 7850 you'd be looking at maybe 28ish then? That's about what I get running a single card. It's not like using a desktop uses much FPS anyway. A 7950 would get 37 or so I would guess if you got 40fps normally. But, that said, sometimes you won't notice any difference.

 

[Pragmata]

Thanks for the reply! That's definitely the kind of information I am after. I want to make as little a dent in my wallet as possible. Currently I am running 3 monitors (limited by ports) on a crossfire 6850 setup, however I am adding in 4 more monitors and to do so will be replacing one of my 6850's with a 7000 series card. So the 78xx would be running 4 monitors and the 6850 3. I'm trying to find the most cost effective way without sacrificing game performance below the 30-60FPS range and I think this is the way I am going to do it.

 

[wolfram23]

Very little impact. I'm running a 1280x1050 second monitor and manage basically normal FPS as with just a single monitor.

As for your idea, well, you can't crossfire a 7850 or 7870 with a 6850. A single 7870 will give really comparable performance to a CF 6850 setup. You should maybe think about selling both 6850s, getting a 7850 or 7870 and a cheap eyefinity edition card which supports up to 6 monitors.

 

[geofelt]

Hi everyone,

I have been trying to get some numbers on this, but can't find a whole lot. What kind of performance hit does adding a monitor to a gpu have? Let's say you are gaming on one monitor at 1920x1080 and you add a second monitor. How does that impact performance by the numbers (fps, percentages). Not to game on the other monitor or do any special crossfire setup, but just there working. Showing you a desktop. Any thoughts?

To give some cards to work with, a 7850 can power through BF3 1920x1080 maxed at ~30FPS (acceptable in my books). If I add in a second monitor (still playing on only one) what kind of fps drop would you be looking at? A 7950 can do the same game at ~40FPS on max everything. Is that enough to offset more monitors? Is it just a matter of VRAM?

Thanks!

For what it is worth:

I have two 2560 x 1600 monitors and a GTX580. I game on one and the other is for static stuff. I detect no difference when using just one monitor.
At one time, before, I added a second cheap graphics card for the static monitor. I figured that dedicating the strong graphics card to gaming would make a difference.
Good theory, but I could detect no difference. I have now reverted to attaching both monitors to the same card.

 

[Pragmata]

@wolfram23: Well aware you can't crossfire cross-generation, I have no intention to. Performance wise it isn't cost effective to try and get equal performance from a single card for my CF6850's, so instead, I am just looking for a single card that can push the settings I deem acceptable (high/ultra @ ~30-60FPS 1920x1080) which the 78xx line falls into. I have no intention of selling my cards as I will most likely make another rig with it. I never sell computer parts, they are too valuable 5 years down the line when you realize you want another cheap linux box to use as a server/htpc/etc. I was recommended to get an eyefinity card, but I haven't been able to find a way to buy two new cards cost effectively. Maybe further down the line I will replace a 6850 with one.


@geofelt: Thanks for the info! I do need two cards as I need the extra slots for monitors, but that is definitely the testing info I am looking for. If I can get good performance from a mid-range card while using the maximum number of monitors at it (especially with those kinds of resolutions!) I will be happy.