Gaming with Dual Monitors

[PerfeK]

This is just a public service annoucement to all those using dual monitors. When you are ingame it will really help if you turn off the secondary. I used to keep mine on, not thinking about the actual performance dip. I always thought everything was a little sluggish but I thought it was just in my head. I decided to check this out and got some interesting results.

3DMark05 v1.2.0

Secondary Enabled' - 5116
Secondary Diasabled - 5413 (my personal record)

How the second monitor accounts for 300 marks, I don't know. Just thought I'd let you know.

 

[ZobarStyl]

Sorry, but no dice. Any well built game won't really show a difference; I've used dual screen for over a year and seen no loss in performance in any scenario other than having a windowed game cross screens. Besides, that's not a huge difference (5%) and it's in 3DMark of all programs, which has very little bearing on real-world scenarios.

 

[pulsedrive]

Yeah, unless you are not confirguring your monitors correctly and part of the screen was being rendered on the other monitor, which would actually result in a MUCH higher loss in performance. Then you shouldn't be having this problem. My guess is that 3dmark is just bithcy.

 

[Lonyo]

The card still has to output desktop to the second monitor, using some resources, and more of the system and video RAM will probably be used to store desktop information.
I wouldn't be suprised at a very slight performance hit, but that much seems a bit much.

 

[Osprey]

EDIT: Thanks to cbehnken for pointing out Doom 3's timedemo problem with dual monitors. That pretty much throws most of the following post in the trash.

Wow. Thanks, PerfeK. I've always noticed that Windows apps that I displayed on the 2nd monitor were much, much more sluggish (WMP visualizations, for example), but it never seemed that having the 2nd monitor enabled made any difference in-game. 90% of the time, my 2nd monitor is showing nothing but the wallpaper (no programs, no start bar, no icons, nothin'), so I figured the performance hit would be minimal. Apparently, that was a false assumption.

I got only a 100pt jump in 3DMark by disabling the 2nd monitor in my display properties, but, as the 2nd poster said, 3DMark doesn't mean much... so, I fired up Doom 3. I ran timedemo demo1 in Doom 3 (at 1600x1200, all high detail) and got 33.4fps with the 2nd monitor enabled and 50.2fps with it disabled! That's not a "slight" difference; that's huge. I'm going to keep the 2nd monitor disabled for the time being and see if benefits other games (particularly D3D games) to a similar extent.

Pulsedrive, you seem to be implying that there's a "proper" way to set up dual monitors so that no performance hit in incurred in games. Would you please elaborate? As far as I can tell, there are only so many nview configurations and they all show the desktop, which would theoretically mean performance hits in all cases.

EDIT: I've tested with a D3D game, RollerCoaster Tycoon 3, and there was absolutely no difference. So, maybe it's something with OpenGL or, specifically, with Doom 3.

 

[cbehnken]

Originally posted by: Osprey
Wow. Thanks, PerfeK. I've always noticed that Windows apps that I displayed on the 2nd monitor were much, much more sluggish (WMP visualizations, for example), but it never seemed that having the 2nd monitor enabled made any difference in-game. 90% of the time, my 2nd monitor is showing nothing but the wallpaper (no programs, no start bar, no icons, nothin'), so I figured the performance hit would be minimal. Apparently, that was a false assumption.

I got only a 100pt jump in 3DMark by disabling the 2nd monitor in my display properties, but, as the 2nd poster said, 3DMark doesn't mean much... so, I fired up Doom 3. I ran timedemo demo1 in Doom 3 (at 1600x1200, all high detail) and got 33.4fps with the 2nd monitor enabled and 50.2fps with it disabled! That's not a "slight" difference; that's huge. I'm going to keep the 2nd monitor disabled for the time being and see if benefits other games (particularly D3D games) to a similar extent.

Pulsedrive, you seem to be implying that there's a "proper" way to set up dual monitors so that no performance hit in incurred in games. Would you please elaborate? As far as I can tell, there are only so many nview configurations and they all show the desktop, which would theoretically mean performance hits in all cases.

Doom3 has a known issue with the timedemo and dual monitors. If you run Fraps during actual play you will notice no performance loss when running dual monitors.

 

[So]

Originally posted by: Osprey
Wow. Thanks, PerfeK. I've always noticed that Windows apps that I displayed on the 2nd monitor were much, much more sluggish (WMP visualizations, for example), but it never seemed that having the 2nd monitor enabled made any difference in-game. 90% of the time, my 2nd monitor is showing nothing but the wallpaper (no programs, no start bar, no icons, nothin'), so I figured the performance hit would be minimal. Apparently, that was a false assumption.

I got only a 100pt jump in 3DMark by disabling the 2nd monitor in my display properties, but, as the 2nd poster said, 3DMark doesn't mean much... so, I fired up Doom 3. I ran timedemo demo1 in Doom 3 (at 1600x1200, all high detail) and got 33.4fps with the 2nd monitor enabled and 50.2fps with it disabled! That's not a "slight" difference; that's huge. I'm going to keep the 2nd monitor disabled for the time being and see if benefits other games (particularly D3D games) to a similar extent.

Pulsedrive, you seem to be implying that there's a "proper" way to set up dual monitors so that no performance hit in incurred in games. Would you please elaborate? As far as I can tell, there are only so many nview configurations and they all show the desktop, which would theoretically mean performance hits in all cases.

What video card? I used to see a MUCH bigger performance hit for dual monitors w/ my 9600Pro than I do w/ my 6800GT

 

[Osprey]

Originally posted by: cbehnken
Doom3 has a known issue with the timedemo and dual monitors. If you run Fraps during actual play you will notice no performance loss when running dual monitors.

Ah, thanks for the heads up. I was running Fraps, but wasn't really paying attention to it. Thanks. That explains why I got no performance hit in RCT3.

Originally posted by: So
What video card? I used to see a MUCH bigger performance hit for dual monitors w/ my 9600Pro than I do w/ my 6800GT

6800GT, same as you.

 

[Newfie]

would you get a performance hit when.lets say..primary moniter is running Battlefield 2 while the secondary moniter runs MSN messenger when using a X800XL?

 

[So]

Originally posted by: Newfie
would you get a performance hit when.lets say..primary moniter is running Battlefield 2 while the secondary moniter runs MSN messenger when using a X800XL?

Why don't you try and tell us?

Primary: CoD
Secondary: GAIM, Coolmon, Winamp

9600Pro: NOTICABLE (~33%) performance hit.
6800GT: I don't see a performance hit, I'll have to try turning off the secondaries again.

Now the real question is...what about when you have TRIPLE monitors...does the screen on the secondary card take a hit? What if I put both secondaries on the other card? Would I see a hit then?

I may do some benchmarking tonight. If any of you guys want to remind me to tongiht, I will venture into AT. PM me.

 

[Slugbait]

Funny this thread would come up...my system is a little slower, but has a new vanilla 6800 with unlocked pipes, and I was wondering why I could only get a score of 3070 to 3090. I disabled my secondary monitor, and the score jumped to 3380, which is more along the lines of what I expected. Actual in-game tests I have not done, but I'd be interested just to see if there's any difference.

 

[remagavon]

There is a mouse bug with most games causing it to lag slightly when moved quickly (I use low sensitivity so quickly means fast across 14" of space). Took me like 3 weeks to figure out it wasn't my system but the dual monitors. Argh. The FPS hit is almost neglegable here though, but the mouselag makes it not worthwhile (6800u here).