I'd like to ask rather a amateur question about SLI in v3.2. If I run my sim on a single 1440p monitor in 2560x1440 resolution with 1024 (sometimes 2048) textures, will second 980Ti really help me with FPS increase in dense clouds (meaning 4xSGSAA will be ON) or not? I see that you guys are running multi-monitor set-ups, a solution I'd like to stay away from.

 

Thanks

I run single monitor on my main FS PC, my triple monitor setup is on my FS Test PC.

 

Yes a 2nd 980Ti in SLI should help in dense clouds with 4X SGSS AA, HOWEVER, you need to keep in mind that if you currently drop to 19 FPS (as example) in dense clouds, that 2nd 980Ti would at best case get you up to about 27 FPS and worse case 24 FPS ... for some that might be enough for other's it's still not good enough.  So take whatever your current lowest FPS is in dense clouds and add 25-45% for worse case and best case.

 

I'd recommend using 512 textures (default clouds or REX soft clouds) for cloud textures ... I think some folks have dropped to 256 textures with very good results.  Depends how important it is to you to have very detailed cloud textures.  But if you run 4X SGSS then I'd recommend 512 or 256 cloud textures regardless of SLI or non-SLI.

 

Cheers, Rob.

Understood - thank you, Rob

Hey Fabio,

 

It's been a long long time since I've had any OOMs (going back to P3D V2.x).  Only tips I can provide:

 

1.  Stay with 2048 textures or lower (1024)

2.  If you have OpenLC EU than use Orbx FTX Global and not England region

3.  HT off saves me about 400MB VAS

4.  If you have high levels of AI traffic use AI traffic limiter (available here on AVSIM)

5.  Use default clouds or REX soft clouds (no 4096 textured clouds)

6.  Enable only the 3rd party airport you plan to fly to/from

 

Cheers, Rob.

 

1) Lowered to 2048

2) Will test that, I had Europe region activated

3) I need to go to BIOS settings to change it right? It will be a pain in the a** to change everytime I want to fly, but will give it a try

4) I don't use AI Traffic, only IVAO / VATSIM traffics

5) I use REX Texture and Soft Clouds (they are at 4096 now, will change to 2048)

6) That shouldn't be an issue with P3D V3 right? Since it only loads the active area you're flying

3.  HT OFF works well for VAS on my 5960X, don't know if it works well on your CPU ... but P3D doesn't seem to like 8C/16T.

 

5.  Strongly suggest you drop cloud textures to 512

 

6.  Depends on how many 3rd party airports you have active in the area ... for heathrow close proximity area, I think I have several airports that could be active (Aerosoft, UK2000, Orbx) at the same time since is a very dense area for population and airports

 

Cheers, Rob.

My Fs runs smoother with 32 bit clouds than DXT5 clouds...

Don't know why but it does...

 

 

I'd recommend using 512 textures (default clouds or REX soft clouds) for cloud textures ... I think some folks have dropped to 256 textures with very good results.

 

Is that what is listed as CLOUD_SHADOW_TEXTURE_SIZE in the .cfg file?  The "shadow" part was throwing me off.

 

Thanks,

Jeff

Does MFAA work with P3D?

 

Edit :I know it doesnt work with SLI but just curious

 

 

Does MFAA work with P3D?

 

It did work for me with 2X SGSS in SLI ... but difference was very minor at 4K res, I didn't do any testing with MFAA ... why would it not work with SLI?

 

 

 

Is that what is listed as CLOUD_SHADOW_TEXTURE_SIZE in the .cfg file?  The "shadow" part was throwing me off.

 

Not related, that's the shadow map size ... it'll govern how sharp cloud shadows look on the terrain.

 

 

 

My Fs runs smoother with 32 bit clouds

 

That's my experience also, but this might be GPU dependent.

 

Cheers, Rob.

 

 

It did work for me with 2X SGSS in SLI ... but difference was very minor at 4K res, I didn't do any testing with MFAA ... why would it not work with SLI?

 

Well it was reported as being broken since the 900 series cards were released when used with SLI but I currently don't run SLI so have no way to check. Maybe they got around to fixing it finally. Same with DSR when used with custom refresh rates.

Hi Rob,

First: thank you for grabbing out the SLI-theme and sharing your important results!

I remember first statements from you concerning SLI in 3.0, where you told that two connected GPU's results in a worse performance than with one GPU in 3.0. Have anything change now in 3.2? I tried two GTX 970 and after connecting them to SLI, like I did in 2.5, it resulted in very light microstutters during panning around in VC and outside, comparinging using only one card in single-mode. Now I can read in your measurings that there are improvements with SLI instead of worsenings. I wonder now if these improvements only meets GPU's like 980TI or Titans in conjunction with high settings of AA or even cards like mine with no SGSS-settings? I drive moderate settings only in P3D ( no NVinspector in using) but two monitors 27" WQHD (5120*1440). With using one GPU I have to limit the fps in sim, otherwise I have a GPU-load of 99% steadily but the panning around is very smooth now. Using two cards divids the GPU-load into 50% each other. That shows me that SLI is working (and that' very fine) but there are no improvements in performance, only these slightly stuttering during panning around.
What's your opinion or suggestions about these? Maybe I did wrong settings in NVCP? Can you post your settings in the SLI-section in your NI please?

Kai

Hi Rob,

 

First: thank you for grabbing out the SLI-theme and sharing your important results!

I remember first statements from you concerning SLI in 3.0, where you told that two connected GPU's results in a worse performance than with one GPU in 3.0. Have anything change now in 3.2? I tried two GTX 970 and after connecting them to SLI, like I did in 2.5, it resulted in very light microstutters during panning around in VC and outside, comparinging using only one card in single-mode. Now I can read in your measurings that there are improvements with SLI instead of worsenings. I wonder now if these improvements only meets GPU's like 980TI or Titans in conjunction with high settings of AA or even cards like mine with no SGSS-settings? I drive moderate settings only in P3D ( no NVinspector in using) but two monitors 27" WQHD (5120*1440). With using one GPU I have to limit the fps in sim, otherwise I have a GPU-load of 99% steadily but the panning around is very smooth now. Using two cards divids the GPU-load into 50% each other. That shows me that SLI is working (and that' very fine) but there are no improvements in performance, only these slightly stuttering during panning around.

What's your opinion or suggestions about these? Maybe I did wrong settings in NVCP? Can you post your settings in the SLI-section in your NI please?

 

Kai

 

If i may jump in, because i have the same cards , 2 x EVGA GTX970SC and i see great performance in SLI now with 3.2.

 

I am only running 1920x1200 on one monitor so 4xSGSS is really nice in SLI (heavy weather with ASN has become an FPS factor with 3.2 on my system and i can get 99% on both cards with alot of stutter in some scenarios even with 3 layers using 4XSGSS) (PNW,CYVR FSDT,ASN,REX4 max setting for LOD and autogen etc.)

 

But i dont see these microstutters panning in the VC ? I use NI@29fps btw and (inside P3D)unlimited fps, no vsync,TB=off

 

(need to test ASN settings further)

 

Also i am staying out on the Building shadows. They seem also to have a negativ stutter effect on my system

 

Michael Moe

What's your opinion or suggestions about these? Maybe I did wrong settings in NVCP? Can you post your settings in the SLI-section in your NI please?

 

Hey Kai, I did not change the SLI settings in NI, leave them at default.  Here's the process I use for SLI:

 

1.  NCP - Enabled SLI performance mode

2.  NCP - Manage 3D settings - locate Prepar3D in dropdown, if the "Restore" button is NOT grayed out, click it to restore default profile

3.  NI - locate the Prepar3D profile from the dropdown (note you should NO longer have a Prepar3d profile under the home dropdown, if you still do then something is not correct in your setup/NI and suggest your wipe/re-install driver)

4.  NI - Change AntiAliasing Mode = "Enhance Application Settings", Change AntiAliasing - Transparency Supersample = "4X Sparse Grid Supersampling" - do not change anything else.

 

You can monitor GPU usage with several products, I use EVGA PrecisionX ... if SLI is working well for you, you should see anywhere from 40% load (both GPUs) on up to 99% ... if you monitor power consumption via APC data feed you should also see your Watt usage increase (should almost double in my case 400 Watts normal to 800 Watts under max loads).

 

 

 

If i may jump in, because i have the same cards , 2 x EVGA GTX970SC and i see great performance in SLI now with 3.2.

 

Thanks for chiming in Michael with your 970 SLI experience.

 

Cheers, Rob.

Thank you very much Michael and Rob for your quick replies.

I'll give it a new chance and try the settings recommended by Rob. Hopefully the settings in NI will help. But I'm not very optimistic, honestly spoken: the recommended settings are higher than these I'm using. For me it is not logical that higher settings make a better performance than lower settings. And even with only one card the sim is very smooth and fluid, so with two cards it should run like a horse. But I'll try it again and then I'll be back here. :wink:

 

Kai

For me it is not logical that higher settings make a better performance than lower settings.

 

In terms of 1 vs. 2 GPUs, it would be logical if there is a bottleneck in your BUS and/or CPU ... P3D is all about system balance ... but with that said, I would think a 3930K @ 4.3 Ghz to not be a bottleneck ... have you done any RAM latency/bandwidth testing?  What speed is your PCI-e operating at (100Mhz)?

 

EDIT: some motherboards also don't support SLI very well, only one x16 slot and the other slot is really an x4.

 

Cheers, Rob.