Dual Monitor setup murdering FPS

Ok.. First off, here is my system.

Athlon64 x2 4400+
XFX 7900GTX 512mb
1gb ram

I'm waiting for some new ram though, a couple of 1gb dual channel sticks. what my problem is, I am running dual monitors, and SL dies completely unless I have the draw distance down at 64.. even sometimes then it starts lagging extremely badly. With the dual monitors I get anywhere from 2-6fps, with single monitor I can get up to 22.. I run SL on the primary monitor only, and with this setup I simply dont understand what the problem could be.. Not to mention I think I should be getting way more than 22fps with a 7900gtx.. I had the exact same problem with my old system, which was an A64 3400+, 6800gt, and 1gb of ram.. I think even the old system should have handled itself better than this. Please, I'm getting a little desperate and need some new ideas on the problem.

Do you happen to be running in a window? I had problems with both SL and World of Warcraft while running in a window... it turned out in both cases, my window was about one pixel over into the other monitor. Trying to run 3D on both screens is what caused poor performance. I set up both programs to start maximized (so they stayed in one screen) and it worked much better for me.

I run secondlife in a window, but maximized on the main screen, so there is no overhang onto the second monitor. I cant set it to full screen mode as I am constantly clicking out of secondlife on the other screen, and in full screen mode it will minimize it when it's not the main focus..

[edit] Turns out that if I place it on single monitor mode, open secondlife, then put it back to dual monitor, it will allow me up to about 20fps.. though you could imagine the drama this causes with icons and windows and such.. Still.. I should be pulling more than 20. =/

I'm running SL spanned across 2 monitors, at 3200x1200, with no framerate issues. My graphics card is a Geforce 6800 GT PCI-Express with 256 MB DDR3 SDRAM. I have no issues in windowed or fullscreen mode.

What revision of Forceware drivers are you using? Also, are you running the latest mobo drivers?

Are you attempting to run the monitors at different resolutions / refresh rates?

Are you sure it isn't a network issue? Nw issues will bring SL to its knees. Check your PING SIM and PING USER times in the debug panel. High ping times (over 100 ms) indicate network issues and will kill your framerate. When I see terrible ping times like that, the only thing that's helped me is restarting my PC. It's like Window's network stack gets hosed and only a full restart will fix it.

That's exactly why it's bothering me >_> I'm running Forceware 84.21, the latest as far as I know, I've updated to latest motherboard drivers with no luck, I'm running an Asus A8N32-SLI Deluxe, and I'm certain this isnt network problems, while my sim ping seems to jump from 100-600.. but it's easy to tell the difference between network lag and graphical lag.. Though I do wonder now why my ping is so eradic..

SL uses its own, custom, "reliable" UDP to communicate between client and server, instead of using TCP. Linden Lab designed this reliable UDP transport to avoid the overhead of TCP. Linden Lab now acknowledges that using this transport was not the best decision in the long run. The transport is prone to packet loss. Linden Lab would like to switch SL to TCP, but hasn't yet.

I don't know if this is your issue, but it doesn't help.

It just doesnt explain why I would get a higher, more playable framerate in single monitor mode.. and why others can use dual monitors on much less powered graphics cards with no problems.. If network problems were causing the loss in fps then the number of monitors shouldn't make any difference -_-
Thanks for the input though.

I'm sorry, just a bump up, as this problem is really killing me, you can imagine paying this sort of money for a system, where SecondLife is the main program that is used on it.. Yet I can't play anywhere near the capabilities of the computer..

Tried having 2 small SL windows that nowhere near the screen edges, or does it still do the same?

Tried the smaller window just then, still no luck though, I got like 1 extra fps probably simply because it was a smaller area to render..? Though the size of my window, and the positioning really shouldn't be the issue, my computer is more than equipped to handle it.

I'm going to chime in here because I recently got dual monitors--two Samsung Syncmaster 204Bs, each running at 1600x1200. Very nice monitors but I, too, have noticed performance degradation with Second Life when both monitors are in use--"Extend my Windows desktop onto this monitor." I expected the framerate hit to be slighter.

For example, using an SL window sized to about 1200x800 and entirely placed on a single screen, draw distance = 160 m, standing at Sanctum Sanctorum (203, 114, 62) looking northwest. Also, all Graphics Detail settings are turned up, except for all four Detail sliders in the middle. I wait awhile and let things settle so everything is rezzed:


On single monitor (other one is disabled) = 30 FPS
On either monitor when in dual-monitor mode = 22 FPS


The cumulative effect noticeably gets worse when there's a lot of avatars and complex geometry around, like in the Welcome Area. I'll regularly experience a drop of 5-6 FPS at the lower range of things, e.g. 10 FPS with single monitor and 4 FPS with dual, which feels quite substantial.

BTW, this is with Processor Affinity set for both cores on my Opteron 170. Nvidia GeForce 7800GT graphics card. 2 gigs of RAM, Asus A8N-E motherboard. Not too dissimilar from Luke's rig.

Luke, since you're also on a dual-core AMD processor, have you noticed any substantial performance gains/losses from changing affinity? (Ctrl-Alt-Del, Processes tab, right-click SecondLife.exe and choose "Set Affinity".) If you have the stats bar open, you can easily monitor differences.

paulie, I'm curious, what sort of FPS differences do you see when running in one monitor vs. two? If you have a moment to try that out?

This is my first dual-monitor setup, so I don't have experience playing games on one monitor and spreadsheets on the other, or anything like that. This might be "typical", or it might not be; anyone else with experiences care to share?

Thanks for the info, I guess I'm glad I'm not the only one with these sort of problems.. Though mine gets unplayable at times because of it.. I gave setting the affinity a try, I actually experienced a loss of a couple of fps when setting it to only one cpu. Thanks for the help, it seems maybe there's just something wrong with how the engine runs on my system.. maybe I'll have some better luck with the Havoc 2 engine when it eventually comes out.

Luke, I was doing some more fiddling and I noticed something very strange. How much CPU % is SL using in Windows Task Manager when you have it displayed on one monitor but dual monitors are active? The reason I ask is because I noticed SL was using 60-70% upon login, which is odd, because when I run it on a single monitor, it only uses 50%--full usage of a single core as expected.

However, if I uncheck and OK one of the CPU cores, then recheck and OK it, I notice that SL uses 99% CPU--meaning almost fully using both cores (!).

If I run SL on a single monitor, then I do notice usage peaks at about 60-70% for a few seconds and then switches automatically to what it should be, around 50% corresponding with a rise in viewer FPS in the Statistics Bar. Very observable.

If this happens to you too or anyone, feel free to post. I'm going to check with more technically-savvy Lindens because it appears that something's bizarre here on a dual-core, dual-monitor system. At least mine.

Depending on the card vendor, model and even driver version, some cards fail to run hardware-accelerated openGL on more than primary display. This means when you put anything requiring openGL (like SL client) on secondary display on such system, it's being rendered through software emulation, and that obviously slows things to absolute crawl like you can experience.

Joannah: I am displaying SL on the primary monitor only, I had already considered this as a problem, but thanks for the help.

Torley: I've just done exactly as you and noticed the exact effects that you've just described.. It's kinda weird but it seems this is somewhat where the problem may be.. o_o

Good to know... if anyone else is seeing this, please post. This is quite unusual (and I have seen a number of strange things in my time).

I am noticing the Dual core problem as well. FPS of 14 or lower in areas with a lot alpha channeled textures and particles. (this includes trees even near the lowest detail setting.) Everything was normal with 30 FPS after setting the process affinity to CPU 0 only, waiting a few moments until my FPS rised, and then reseting it back to both CPU 0 and CPU 1 as you described earlier.

A small annoyance, but nothing the beyondlogic process application and a quick batch file can't make easier to deal with for now.