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View Full Version : UT3 runs worse with 'Enable SLI Technology'


XxDeadlyxX
08-27-08, 12:48 AM
With my GTX 280 SLI setup, I'm having a weird problem.

If I Enable SLI technology in Nvidia CP and set the 3D settings to 'Single GPU', then in-game framerates are noticeably lower than when I choose 'Do not enable SLI technology'. Choosing 'Do not enable..', makes the game silky smooth and rarely dips under 60fps. With SLI Technology enabled, walking around the same maps with no players and FRAPS running the fps is noticeably lower when looking certain directions and firing rocket launcher there etc. I've flipped back and forward while testing it many times so I'm not imagining it.

In general, I've found that UT3 suffers from very slight input lag when I actually enable "Nvidia Recommended" or manually choose AFR2 in the game's Profile settings. Maximum Pre-rendered frames set at 3 compared to 0 and 8 seems to make little difference regarding that as well. Therefore, due to UT3 being a very fast-paced game online where every bit of accuracy helps, I've left it on 'Single GPU', where there is no lag, just like setting 'Do not enable SLI technology'.

When I was messing around with nHancer, choosing 2x2 Supersampling DID give a significant performance increase with SLI compared to Single GPU, however it still not as smooth as "Do not enable SLI technology" with single GPU and no AA.

I very much doubt there is a solution to this and it's probably a bug of some sort. Crysis runs really good with SLI and obviously I want to be able to use SLI on other titles without this issue, so choosing "Do not enable SLI technology" is not an option unless I was to change it every time I played UT3.

Any thoughts?

Kaguya
08-27-08, 01:50 AM
If you do find that UT3 runs better on a single card, i don't think you need to disable SLI manually each time, can't you just use nHancer to force a different SLI profile, say Single GPU instead of whatever is there by default?

Also, just out of curiosity, have you tried enabling VSync (and triple buffering if UT3 has that)? I found in some games that enabling VSync smoothed them out noticeably in SLI.

XxDeadlyxX
08-27-08, 02:18 AM
If you do find that UT3 runs better on a single card, i don't think you need to disable SLI manually each time, can't you just use nHancer to force a different SLI profile, say Single GPU instead of whatever is there by default?

Also, just out of curiosity, have you tried enabling VSync (and triple buffering if UT3 has that)? I found in some games that enabling VSync smoothed them out noticeably in SLI.

Already tried that. It seems to have nothing to do with choosing Single GPU or any other mode (Auto or AFR etc), anything when Nvidia CP is set to 'Enable SLI technology' does not give as good fps as 'Do not use SLI technology'.

I am running Vsync.

Best way I can describe it is, if I go on Deck with 'Do not use..' and have no bots then the framerate pretty much does NOT go lower than 60fps except to 58-59 occasionally. If "Enable SLI.." is chosen and I do the same thing, the fps drops to 50 and in the 40s when I fire rockets into the middle of the map etc.

Digital_Trans
08-27-08, 03:28 AM
HAHAHA UT3 sucks~~~~

Kaguya
08-27-08, 11:32 AM
Already tried that. It seems to have nothing to do with choosing Single GPU or any other mode (Auto or AFR etc), anything when Nvidia CP is set to 'Enable SLI technology' does not give as good fps as 'Do not use SLI technology'.

I am running Vsync.

Best way I can describe it is, if I go on Deck with 'Do not use..' and have no bots then the framerate pretty much does NOT go lower than 60fps except to 58-59 occasionally. If "Enable SLI.." is chosen and I do the same thing, the fps drops to 50 and in the 40s when I fire rockets into the middle of the map etc.

Wow, that's nuts... there's something screwy going on. Have you tried uninstalling, cleaning and installing the newest betas (177.92 I think). They've been great for me.

XxDeadlyxX
08-27-08, 06:37 PM
Wow, that's nuts... there's something screwy going on. Have you tried uninstalling, cleaning and installing the newest betas (177.92 I think). They've been great for me.

Yeh I just formatted and installed 177.92 clean and it's the same :(

What I have figured out though, is that the lower fps with Enable SLI seems to be directly related to CPU/memory speed. If I go back to stock 2.4GHz, the fps will be about another 10 frames lower again (really bad). Increasing my memory clock from 800 4-4-4-12 to 1066 5-5-5-15 makes it increase by about 2-3fps.

Maybe enabling SLI automatically makes you heaps CPU limited? That's what I initially thought, because my results at 640x480 are identical to 1920x1200.

john19055
08-28-08, 07:55 AM
They are some other games that run better with just one GTX 280 then with two in SLI like,Quake Wars - Enemy territory and Tom Clancy's Ghost Recon: Advanced Warfighter 2
until you get to 2560x1600.It does'nt make a lot of since unless it is the drivers.some say it is CPU bound and needs a lot faster CPU.

XxDeadlyxX
08-28-08, 08:00 AM
They are some other games that run better with just one GTX 280 then with two in SLI like,Quake Wars - Enemy territory and Tom Clancy's Ghost Recon: Advanced Warfighter 2
until you get to 2560x1600.It does'nt make a lot of since unless it is the drivers.some say it is CPU bound and needs a lot faster CPU.

Yeah, the faster I make my CPU, and memory MHz too, the higher the minimum fps is with 'SLI Enabled'.

I've found that with CPU at 3.4-3.6ghz, memory at ~1000+ @ 5-5-5-15, and World Detail at 2 (LOL), I can get a constant 60fps with 'Enable SLI technology'. So that's what I'll use, as I play UT3 just online now, so not too concerned with the eye candy. Constant 60fps is the most important thing. Increasing World Detail, even to 3, results in noticeably worse fps.

FearMeAll
08-31-08, 08:08 AM
This is why I'm sort of glad after 3 years of using Sli, I'm back to single card. So much fiddling you have to do...so much..

MisterMister
08-31-08, 01:22 PM
You know, I really dont get the big deal with SLI (problems wise). Ive been using my 9600GT SLI setup for about 6 months now without a single problem. In fact the BIGGEST "issue" I've ever encountered is having to re-enable SLI in the Nvidia control panel after changing/updating the drivers!

On my current system/setup, I've played (in no specific order):

The Orange Box (HL, HL2, HL2 ep. 1 & 2, TF2, & Portal); Need For Speed: Pro Street & NFS: Undercover; G.R.I.D. ; Call of Duty 2 & COD 4; DOOM3; F.E.A.R. & it's expansion packs; Supreme Commander; Black & White 2 & "Battle Of The Gods" expansion pack; Crysis; Far Cry; Battlefield 2 & 2142; Tiger Woods PGA 2007 & 2008; Bioshock; Gears of War; Star Trek Legacy; UT04; UT3; Devil May Cry; IL2 Sturmovik; Americas Army; Quake III Arena; Fallout 2; GTA: Vice City; GUN; Rainbow Six 3; Microsoft Flight Sim X; Microsoft Combat Flight Sim 3; & Sins Of a Solar Empire... and that's what I just remember off the top of my head! It's also not including the handful of game demos which I have downloaded and played (with similar results).

I should also mention that I have run benchmarks including 3DMark 2001SE, 2003, 2005, 2006, & 3DMark Vantage... as well as AquaMark, PCMark06 & PCMark Vantage.

I have been able to play ALL of these games/programs with my SLI setup without issue ONE. No noticable "micro stuttering", no huge drops in performance, no freezing/crashing, or any other issues which would scream "its SLI's fault!"...

...And as you can see I've played everything from classics from the 90s, all the way to the latest and greatest current titles... as well as a myriad of graphic & system benchmark programs.

So with that, I have to say, SLI has been VERY good to me. I get kick ass benchmark scores, and I can play every game I just mentioned (with the exception of Crysis) at it's respective maximum detail settings (including AA/AF) @ my screen's native resolution of 1680x1050. And when I say "I can play" I mean I am getting (very) near, at, or above a 60FPS average frame rate. All of which being run on a pair for mid range video cards which can now be had for under $100 USD each (I did pay ~$140/ea when I first bought them 5+ months ago of course)! Now, THATS "bang for your buck" any way you look at it IMO.

To bring things to a finer point... going off of my first hand experience with SLI... I must admit that I not only have NO qualms with it but I also have no doubt that I will be using SLI and/or multi GPU video card setups in the future.

-MM

H3llF1re2008
09-13-08, 07:29 PM
Hey buddy. Just found this thread via a Google search - thought I'd just post my experiences. I've just recently upgraded my rig with GTX280 SLI (managed to grab the cards for a real good price). Nforce 680i, E6850 (stock clocks presently), 4GB Geil black dragon, 1000w PSU, Vista 64bit SP1 (and also I have the Antec 1200, as well! :-)).

Generally I'm really happy with the cards - seeing great scaling in games like Crysis and Bioshock. Unfortunately though UT3 actually, if anything, plays worse than before with my old (single) 8800 card! Like you, I get performance gains if I uncheck "Enable SLi Technology", but the FPS still isn't right, and tends to drop below 50 regularly during busy games in maps like Shangri La. Strangely reducing detail levels doesn't seem to have a noticable impact on performance (even though the FPS reports higher) - it still "feels" laggy to play! :-( Really hoping it's just a driver issue that they are working on.

Please let me know if you find any solutions or anything that helps!

Cheers,

H3.

mailman2
09-13-08, 10:37 PM
This is why I'm sort of glad after 3 years of using Sli, I'm back to single card. So much fiddling you have to do...so much..


QFT - never again am I gonna use dual GPUs even 9800gx2 did this to me. Single card FTW.

Lfctony
09-13-08, 11:54 PM
CPU limited games run slower with SLI enabled(the CPU takes a hit because it synchronizes SLI). UT3 is most likely one of those cases... I'm just guessing here, I don't have UT3 installed. You have seen this yourself though, decreasing the CPU caused the speed to drop even more, which indicates a CPU limitation...

XxDeadlyxX
09-14-08, 01:28 AM
Hmm.... something I've noticed, after re-installing 177.92 recently, the problem seemed to go away (I could get 60fps constant with SLI enabled but Single GPU in UT3 app options, and World Detail at 4). However, this only seemed to last for about a day, then it was back to the way it was, with fps quite easily dropping below 60fps on World Detail 4. I had changed nothing at all, it went back bad by itself. So... something must be causing it...

I can do a simple controlled test to determine fps, what I do is go to the Deimos map, go where the Shock rifle pickup is, and look towards the center of the map and fire the link gun. When it's bad, fps will dip to 50-58fps when firing the Link gun and it will appear very unsmooth (I'm running Vsync). However, when the problem had rectified itself for a short while after installing 177.92, I would get constant 60fps. Decreasing World Detail to 2 however makes me get constant 60fps regardless, but it is incredibly stupid that I even have to contemplate running at that setting considering the $$ I've spent on my hardware.

With my 8800GTX and CPU at 2.8GHz before I upgraded, I could run at World Detail 5 without problem (60fps). If I try to do that right now, fps will dip to as low as 35fps in action.

The thing is.. UT3 DOES scale if I force AA and use Nvidia Recommended SLI setting (or force AFR2), however I do not want to run SLI in UT3 as the game's responsiveness is worse than with Single GPU (if I was playing offline I wouldn't notice it, but online my score is worse with SLI every time, and I can 'feel' it isnt as good). In contrast, playing Crysis single player with SLI enabled is great, because it's a slower paced game and super-duper reflexes aren't really required. The lower responsiveness may just be a UT3 thing anyway, I can't really notice it in any other game, but to be fair, UT3 DM is much faster paced than other recent games.

As for microstuttering, I have only noticed it when I enable AFR2 and UT3 is running at low settings (ie. World Detail at 2), then it will stutter. However if I give the GPUs enough work to do, it will not stutter. Haven't noticed the microstutter on any other games either.

Regarding SLI causing CPU limitation, from what I can tell from increasing and decreasing CPU speed with SLI enabled, I would need over 4GHz to get anything close to my 8800GTX and 2.8GHz fps at the same settings, as even 3.8GHz (PC obviously wasnt stable at that speed, but I still tried it), fps still dipped below 60fps very often at World Detail 4.

It just sucks to think that I could play with World Detail 5 perfectly on my 8800GTX, yet I'm having to use World Detail 2 with my current setup to get the same fps. World Detail 2 makes certain maps look very bland (ie. Deck)

H3llF1re2008
09-14-08, 10:18 AM
Hey Deadly, cheers for the reply. I've been doing a lot of messing around with this, and I think I've found something that makes a difference. For me, doing this provides a fairly massive boost in FPS and actually makes the game playable at 5-5 detail levs (it's still not constant 60FPS as it it really should be with this sort of set up, but it fluctuates less and tends to stick around the 60FPS mark more reliably - it also feels a lot smoother to play). Here goes:

1) run UT3 as administrator (I don't think this helps, as such, but I tend to run everything in Vista as an admin, so if you want to duplicate what I'm doing "to the letter" then I recommend doing the same)
2) launch the game, full screen mode, and alt-enter it when you get to the menu to go to windowed mode
3) do a ctrl-shift-esc to pull up task mangler, and click the processes tab
4) click "show processes from all users" to make sure you have admin privs, and find "UT3.exe"
5) Right-click it - Set Priority - click "Realtime"
6) Click "Change priority" to confirm, close task manager and alt-enter back into UT full screen
7) fire up a game and see if it's any better. I was able to go to a spot in Shangra La (bridge outside) where I was previously getting 40FPS - now hovers around 60.

Now obviously this isn't a "fix", and I don't know if it's even recommended to run this game in Realtime mode (it probably isn't, TBH), but I've played for about 30 mins with it and didn't notice anything unusual (except obviously a more acceptable frame rate! ;-))

Give this a shot if you can. I'd be real interested to know if it makes the game any more playable for you as well.

Cheers,

H3.

hell_of_doom227
09-14-08, 12:17 PM
UT3 runs fine here.

XxDeadlyxX
09-14-08, 08:08 PM
Hey Deadly, cheers for the reply. I've been doing a lot of messing around with this, and I think I've found something that makes a difference. For me, doing this provides a fairly massive boost in FPS and actually makes the game playable at 5-5 detail levs (it's still not constant 60FPS as it it really should be with this sort of set up, but it fluctuates less and tends to stick around the 60FPS mark more reliably - it also feels a lot smoother to play). Here goes:

1) run UT3 as administrator (I don't think this helps, as such, but I tend to run everything in Vista as an admin, so if you want to duplicate what I'm doing "to the letter" then I recommend doing the same)
2) launch the game, full screen mode, and alt-enter it when you get to the menu to go to windowed mode
3) do a ctrl-shift-esc to pull up task mangler, and click the processes tab
4) click "show processes from all users" to make sure you have admin privs, and find "UT3.exe"
5) Right-click it - Set Priority - click "Realtime"
6) Click "Change priority" to confirm, close task manager and alt-enter back into UT full screen
7) fire up a game and see if it's any better. I was able to go to a spot in Shangra La (bridge outside) where I was previously getting 40FPS - now hovers around 60.

Now obviously this isn't a "fix", and I don't know if it's even recommended to run this game in Realtime mode (it probably isn't, TBH), but I've played for about 30 mins with it and didn't notice anything unusual (except obviously a more acceptable frame rate! ;-))

Give this a shot if you can. I'd be real interested to know if it makes the game any more playable for you as well.

Cheers,

H3.

Thanks for the suggestion, unfortunately that didn't help my fps at all with World Detail at 4, exactly the same as with not changing the priority :(

Hmm looks like I'm have to stick with World Detail 2 :(

JoJomomo
09-14-08, 09:47 PM
UT3 runs fine here.




Well of course it does, I mean after all according to you Nforce chipsets are better than intel chipsets and SLI'd 280's are a better bang for the buck than a HD 4870X2 :headexplode: