prccowboy

BabyPapa1, Thanks for sharing your results I feel like I need to show some hard number results also to confirm the statements I made earlier that SLI DOES work but performance will vary if you have something else bottlenecking your framerates. Specs are: i7-3930k, EVGA 580gtx 3Gb (x2), RAM:16Gb 2133Mhz . Test is run @1080p with DS, MSAA=2x, AF=2x, FXAA on and Fast Sync. SLI enabled by compatibility bits only (see above suggestion from BabyPapa1) Test is Georgian Hammer 6-2 mission because it is hard on my rig. First photo is baseline (36 fps), showing test at "stock" cpu speed and sli disabled. GPU is at 99%. I am clearly limited by GPU 2nd photo confirms GPU is bottleneck because overclocking CPU has NO performance gain. Still at ~36 fps and GPU is at 99% 3rd photo shows SLI does work (53 fps, a 47% improvement), but gain is limited because I hit CPU bottleneck with "stock" speed. GPUs are underutilized at 85/78% Last photo shows SLI working @ 96% utilization on both cards when I remove CPU bottleneck by overclocking CPU (now at 63 fps, a 75% improvement) Under different test conditions, I can load the CPU so much that SLI shows no improvement (or worse) Note: I reduced photo size to upload and Yes, I know my rig is very dated now. It was top shelf when I built it for the original A-10c standalone but with DCSW 2.5, I need as much extra performance as I can get by using SLI - hence this thread.

I suspect with your system that you are rarely getting cpu bottlenecked which allows your SLI to be better utilized. I have great SLI results in NTTR map but parts of the Caucasus map seems to be more cpu demanding. I'm now using the Georgian Hammer 6-2 mission for benchmarking because it seems to "hammer" my system the most and serves as a good worst case bench for tweaking (it has clouds too - which allows me to test for SLI induced flicker) If you get bored, I'd be interested in your SLI vs. Non results using that mission.

I'm not sure if this will help but it sounds like your problem is related to processor load (when fps drops the problem is more apparent), so maybe if you change the TIR processor affinity to a cpu core that DCS is NOT using or change the TrackIR process priority then it might be more responsive. (both settings accessed from Windows Task Manager, Details tab, and right click TrackIR. you can also use Task Manager to determine which cpu core DCS is using)

strange... problem popped back up for me then disappeared again when I changed gamma settings - will play with this some more.

There are other threads that explain it better but I think in a nutshell: preload radius affects how much is "preloaded" into RAM vs. HDD access (so if you have the RAM you can safely max out the setting) visibility range is how far out you can see objects, shadows, etc. - so this setting can have a huge impact on the cpu load in densely populated areas of the map. I would suggest lowering this setting first to see how much it frees up your cpu

If you try processlasso(?), report your results back here. I'm curious if it has much improvement over setting w10 game mode and using high power profile also, have you tried reducing your "visible range"?

Drag80, you are probably getting bottlenecked by CPU. After I initiated this thread and did a lot of experimentation, I discovered that's what happened to me. Under certain test conditions, the CPU was limiting the framerate. Because the videocards weren't the bottleneck, one gpu was able to handle the load (and two gpu's was overkill resulting in reduced gpu utilization but no increase in fps). I reduced visible range and overclocked my cpu which made a massive difference. (now without a cpu bottleneck the difference between running SLI vs. single gpu was huge - went from about 44fps to 75fps, now my gpu's are probably the bottleneck again) edit: I changed my first post to discuss my conclusion about SLI working or not

I have had similar issues in SP (running SLI) where the "dark underbelly" of the clouds would intermittently flicker especially when moving view - at times it seemed like a flat black texture was briefly replacing part of the cloud. funny, I can't replicate the problem now (don't know what I changed)

Since you are currently using a hat switch for view, a good compromise between your current setup and VR may be to get TrackIR. You will keep your higher resolution, keep your SLI benefits, AND you will have much better situational awareness and ability to look around (vs hat switch).

lol, I just edited my earlier response to remove the custom resolution solution and tell you another way. regardless, glad it's working for you now

I recall having a similar problem when I was playing with DSR but I can't replicate it now to tell you 100% how to fix. edit: ok, I managed to replicate the problem. I think you can resolve it by NOT clicking "Full screen" in the menu (make sure it is unchecked). Then start the game windowed and press "L-Alt+Enter" to go full screen edit2: pasting back part of my original response since it seemed to work and may help someone else: "make sure your video card has a matching resolution listed (or make a custom one to match)"

Have you monitored your other system components when you have the stutters (ie. cpu load, hdd, memory, network). It may not be video card related. My gpu utilization (with SLI) will drop significantly when cpu load increases (one of the cores maxes out) but stutter could also be related to disk access or even network use (especially in Windows 10 with background tasks)

Isn't it funny how DCS helps you identify PC issues? I just discovered that I have been underclocking my memory for years because I missed a BIOS setting when I built the rig. I would never have seen it had I not been trying to get a little more fps for DCS. Not sure if I actually get any performance bump from it, but it makes me feel better that my memory is now running at advertised speeds.

Yeah, try not forcing DX11 AFR2. I discovered that under certain conditions my performance in 2.5 (especially in Caucasus) was being bottlenecked by my cpu getting maxed out - the video cards were being underutilized so that SLI wasn't making as much of a difference as 1.5/2.2. So, I dropped my visual range settings to reduce the overall load (while increasing MSAA because the gpu's were underutilized anyway) I am happy with performance now - smooth with nice visuals (even in intense combat). I have a minor issue with occasional cloud flicker with SLI but otherwise all is good.

For those who are getting different results than others I have finally concluded what should have always been obvious: Ultimately your performance is either limited by your CPU or GPU (I won't go into other system performance like memory or HDD). Think of it as 2 guys running a race but tied together by a rope. If one is slow, he limits the speed of the other. In DCS, when the CPU gets maxed out then the gpu becomes underutilized and vice versa. Which is why people here get different results when playing with different settings (for some, the video card might be holding them back and for others it is their cpu) AND the limiting factor might change in different game conditions - it is dynamic. e.g. On my rig, while sitting on the runway at Batumi my cpu was underutilized and gpu was the limiting factor (using SLI and reducing eye candy settings could give me a huge performance boost). However, once I flew to a different area and entered intense combat (lots of objects, AI, TGP, etc.) then one or two of the cpu cores became maxed out and the gpu was underutilized (eye candy settings and SLI did NOT impact fps); however reducing cpu load (changing visual range or overclocking the cpu) would boost performance. So, ultimately, your individual fps performance will come down to what is limiting your overall fps (cpu or gpu?) If it is cpu, then change settings that impact cpu load (i.e. visual range, etc.) If it is gpu, then change settings that impact gpu load (i.e. eye candy or use SLI if you have it). edit: another perspective, if you are already cpu maxed, then you can probably start cranking up the graphics settings without lowering your fps You can determine the limiting factor under different conditions by using various monitoring tools. (I use EVGA PrecisionX, HWmonitor, etc.)

thanks. I will take a look

I've been "flying" the A-10C since before DCS World days, back when it was a standalone. I've always been slightly irritated by the engine sounds. Having lived near an AFB with hogs, I am used to hearing that unique awe-inspiring throaty whine of the GE TF34 engines. The engine sound in DCS isn't close. Now that 2.5 is looking so good, that lack of sound immersion is bothering me more. I would love to see DCS improve the sounds here. Until then, does anybody have a recommendation for a decent engine sound mod that works with 2.5?

After updating to 2.5.0.14138, the Georgian Hammer A-10C campaign description is in wrong language (not English) Also, when did the campaign AI voices get text-to-speech voices not human actor recordings? I don't remember this from 1.5

yep, that's what happened. parking was full. Thanks for the feedback.

After flying Georgian Hammer campaign, 3rd mission, I watched my wingman land at Batumi and he VANISHED after touching down on runway. The log showed he landed but instead of taxi/parking afterwards, he just ceased to exist.

I use "Nvidia Profile Inspector" by Orbmu2k. There is another thread in this forum about the app: https://forums.eagle.ru/showthread.php?t=202038

The game bar won't come up if you have disabled aero, use Full Screen Exclusive or have disabled full screen optimizations.

I've used various profiles with success, but I'm currently using a slight derivative of BabyPapa1's suggestion above (only changing SLI compatibility bits DX10+DX11 and not forcing AFR2) I also made a few changes for personal taste (set FXAA on and Vsync to Fast) but these changes are really more for quality preferences rather than pure performance.

not necessarily, but it seems to impact some other bottleneck that was throttling my gpu's in Caucasus. After running more tests, I have much better SLI performance gains in other areas of the map but something about my first test conditions @ Sukhumi killed my SLI performance. on Nevada, SLI is a *BIG* game changer for me under all conditions (about 100% improvement). Also, don't you basically disable SLI performance when you use SLI AA?

Yes to Alt-Enter; clean and repair. After more experimentation I have realized that it is NOT an SLI issue - The SLI is working but something related to visible range is bottlenecking my overall performance in Caucasus (such that in most conditions the SLI is running below 50% utilization) If I drop the visible range setting (or change my view to limit the range) then I can get SLI gpu utilization up to 98% and I can see the SLI performance boost. (ex: Single gpu=60fps; SLI=100fps). I changed all other settings (texture level, tree visibility, etc.) and nothing else made a difference. Whatever is causing this performance bottleneck for my rig, it's only in 2.5OB Caucasus. I don't see it in Nevada or 1.5 Caucasus.