SLI working

[335th_GRAthos]

Giving some feedback on the SLI status after the beta 14762:

SLI works fine for me, using STL's solution:

stl Junior Member Join Date: May 2011
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Working SLI-Bits to edit with NVIDIA Inspector 1.9.5.5

Click at Profile Settings (besides the "Driver Version"),
create Custom Profile and click "add application to current profile" to add launcher.exe.
edit:
SLI compatibility bits (DX10): 0x000000F5

NVIDIA predefined SLI mode on DirectX 10: SLI_PREREFINED_MODE_DX10_FORCE_AFR

click on "Apply changes"

EDIT: New solution posted by RickRuski and it works great with NVDIA 285.27 beta drivers and the CoD beta patch

RickRuski
Although I have only recently gone Sli I feel that I have found some things that help to get it running reasonably well.

(1) make SURE that all settings are the same in all adjustments (control panel, Invidia Inspector, etc) sometimes I have found that they aren't.

(2) Try and get all cards balanced so that voltages, frequencies, etc are the same. ( I use EVGA precision Tool for this purpose available at EVGA , my two cards are from different stables and therefore not the same clocks etc.)

(3) Overclocking sometimes has a negative effect (although my cards are factory O/C I have turned them down to stock settings and find them more stable)

Hope these few things that I have found during testing help others who might be struggling.

Here are my new "Profile" settings applied after 285.27 beta driver.

Sli compatibility bits (DX10) 0x00000011
Sli compatibility bits 0x00000011
AA-mode override any application setting
AA-setting 2x (2x Multisampling)
AA-Transparency Multisampling Enabled
AA-Transparency Supersampling Off/ Multisampling
Text filtering-Anisotropic sample opt. OFF
Text filtering-Negative LOD Bias Clamp
Text filtering-Quality Quality
Text filtering-Trilinear opt. OFF
Max pre-rendered frames 3
Multi-display/mixed-GPUacceleration Single display performance mode
Power management mode Adaptive
Treaded optimization Auto
Triple buffering OFF
Vertical Sync Force on

Sli : -

AA-SliAA AA MODE SELECTOR SLIAA ENABLED
Number of GPU's to use Sli SLI_GPU_COUNT_TWO
NVIDIA predefined No.GPU's SLI_PREDEFINED_GPU_COUNT_DX10_TWO
NVIDIA predefined No. GPU's SLI_PREDEFINED_GPU_COUNT_TWO
NVIDIApredefined SLI mode DX10 SLI_PREDEFINED_MODE_DX10_FORCE_AFR
NVIDIA predefined Sli mode SLI_PREDEFINED_MOED_FORCE_AFR
SLI rendering mode SLI_RENDERING_MODE_FORCE_AFR

Other : -

Do not display this profile in the C/P CPL_HIDDEN_PROFILE_DISABLED
Enable application for Optimus 0x00000011 (Il-2 Sturmovik: Cliffs of Dover)

Now have smooth play after cards reach operating temps.
Get EVGA "Precision" tool to show fps and card temps, also to balance frequencies and voltages. These will display on screen instead of using "Fraps".

RickRuski

I am flying in Window mode 3072x1024 (my desktop is 3840x1024) so that I have enough space to monitor the GPU settings.
Interestingly enough, the fps depend on the level of utilisation %percent of the GPUs.
Over sea I get the GPU utilisation% on both cards at 99% percent.
Over ground there are variances but usually something between 65% - 75% would be a good mark.
On the REPKA Server #islands (lot's of water) I have constantly 90-110fps, GPU utilisation at 85%-95%, GPU temp is at 85°C
On the REPKA Server #Channel (simple ground set) I have constantly 70-80fps, GPU utilisation at 80%-90%, GPU temp is at 85°C
On the REPKA Server #Channel (heavy ground set) I have 30-50fps, GPU utilisation at 60%-65%, GPU temp is lower

The Black Death track seems to be very heavy, GPU Utilisation varies as the pictures below will show you:

The biggest challenge was the GPUs temperatures, the first SLI setup brought the GPU temp to 92°C
so I had to add an additional 120mm fan to push fresh air into the case and do some additional air flow optimisations
which brought the temp at constant 99% GPU utilisation from 92°C down to 85°C
You need to keep an eye on your GPU temp, I used to think the NV6800Ultras were hot but, this 90°C is scarry...

Flying a mission (above water, bombers intercept) gives me a clear SLI advantage (almost double fps)
The shadows seem to be the fps killer, removing the tick from the shadows has a dramatic increase in CPU utilisation%
and fps performance
Sorry for the big screens, this is my desktop and I did not want to manipulate the original quality of the pictures by
making them smaller... on the far right you can see the GPU performance window.

3840x1024 desktop, 3072x1024 window (beta 14762) move sliders to the right to see the game and GPU graphs
With SLI

Without SLI

settings



What is however very interesting is that I do not notice difference in fps performance on the Black Death
between SLI and NO-SLI mode! I do not understand it and it makes me wonder.

Anyhow, perfomance is good (SLI and no-SLI) and as long as shadows are off, I am very happy with it!

3840x1024 desktop, 3072x1024 window (beta 14762) move sliders to the right to see the game and GPU graphs
With SLI

Without SLI

settings


The shadows seem to be the fps killer, removing the tick from the shadows has a dramatic increase in CPU utilisation%

and fps performance
3840x1024 desktop, 3072x1024 window (beta 14762) move sliders to the right to see the game and GPU graphs
With SLI

Without SLI

settings


The grass and roads do not seem to make a big difference after the Shadows are off
3840x1024 desktop, 3072x1024 window (beta 14762) move sliders to the right to see the game and GPU graphs
With SLI

Without SLI

settings



As a side comment, I never had the "sound bug", I posted my sound at conf.ini in a different thread in the hope that it
may help others.
I also use the RAMDRIVE solution (6Gb RAMDRIVE), I liked it and got used to it, apparently it does not have any impacton performance but I mention it, just in case.
Many thanks to Jimbob for his nice explanations: http://forum.1cpublishing.eu/showthread.php?t=20228
For me it looks smooth and the only thing I am waiting for is the 3monitors implementation like in the old IL2FB...

And for those who want to understand more about the headaches of SLI, Flyby posted an excellent link:

Originally Posted by Flyby

It's over on the Tech Report, and speaks to a new consideration for benchmarking GPUs versus the general FPS performance testing used by the site now.
A good read: http://techreport.com/articles.x/21516
I hope some find it useful.
Flyby out

~S~