Benchmark analysis part 1: over water. VRAM bottleneck ?

[Skinny]

HI all,

Ive been doing some benchmarking with CoD and thought you might be interested in the results so far.

First of all, in this post, all results where obtained using my Turkey Shoot track, which is pretty light, and only over water, ~10 planes. You can watch it here:

http://www.youtube.com/watch?v=Or6pe...layer_embedded

I intend to add benches over land later, but I might need a better videocard to make that useful.

My specs: Core2 Quad @ 3 GHz, 4870 512 MB, 4 GB RAM.
Reference settings I used, is the best balance between visuals and performance for my rig:

resolution: 1360x768  
anti aliasing: 4x 
Epilepsy: Off
Model: high
building: low
land:low
forest:low
effects:high
damage decals:medium
buildings:low
land shading: low
grass: off
shadows:off
roads:off

Lets check performance impact of some of the relevant IQ settings. First I wondered about damage decals:



There is barely any difference, but I should add I can also not see any difference in the track. Perhaps this only applies to the players own airplane?

Next, I quickly toggled a few other options:



Note that 'reference' refers to the settings I quoted above. Setting model detail to low (or even medium) seems like a pretty damn stupid thing to do. It only affects your own plane which then looks worse than a 1990's flightsim, and the difference in frame rate is pretty small. Do yourself a favor, set it to max.

"Visual Effects" does impact FPS when you would expect it (when bullets are fired and hit), but the performance penalty is modest and the IQ impact huge. Cant see much difference between medium and high here, but you dont want to set it to low I think.

Lastly, As you can see, shadows is a real FPS killer here. A shame, as it look pretty damn nice, but my rig cant cope with it.

Next, lets look how resolution and AA impact framerate on my venerable videocard:



Reducing AA does help framerate, but only in those segments where they are already quite playable. In the segments where I struggle to maintain 30 FPS, AA settings dont matter much, if at all. In short, I better leave it on to compensate for the reduced res, since going to 1920x1080 native res of my monitor is not really playable, even with AA disabled.

One would think I need a faster videocard. But is it that simple?
To find out, I tried over/underclocking my videocard:



Surprising, no? Running my videocard at 50% lower speeds, makes no difference whatsoever, not at 1360, not at 1920 res. My bottleneck is elsewhere, one would suspect the CPU.

Lets see what happens when I underclock CPU and RAM:



Not a whole lot! 50% lower cpu speed again makes almost no difference. RAM speed is even less of an issue.

So what is my main bottleck (again, over water) ? I can only imagine its the amount of VRAM.

Before I start testing over land, I would love to confirm this. Therefore, if anyone has a rig similar to mine, but with a 1GB 4870, please see this post:
http://forum.1cpublishing.eu/showpos...4&postcount=15

[Flanker35M]

S!

Quite comprehensive test there, Skinny! So is the whole performance issue related to memory management as clock speeds do not seem to affect that much at all..

[Skinny]

Originally Posted by Flanker35M

S!

Quite comprehensive test there, Skinny! So is the whole performance issue related to memory management as clock speeds do not seem to affect that much at all..

On my rig, it certainly looks that way. I only have 512 MB VRAM, so its hard to say if people with modern videocards with >1 GB are in the same boat. But considering on the track I used there is no ground, no buildings, no nothing but water, I can only guess how bad the issue is over land. I doubt 1 Gig of vram would suddenly solve everything.

Does anyone know if there is a way to compress textures, like there was on il2?

[Space Communist]

Indeed it looks like right now the only people getting really good performance over land have 1.5-2 gb of vram. What this game really needs is a setup application that can check your settings against your vram and tell you if you are going over like in RoF and other games. I think if it had that a lot of people even before patching could get the game quite playable by manipulating the settings to stay under their vram limit.

Hopefully with patching they be able to get more effects on a smaller memory footprint.

[matsher]

Great info, thanks Skinny...

VRAM it is then... Thats a real bugger.
Do you reckon it is easy to fix??? For the !c team to spread the love,
so to speak, to all the other systems (CPU, RAM etc.)

[BadAim]

I'd tend to agree on the vram theory. I have a 1200mb GTX470 and I get good performance with the settings turned down somewhat. The buildings are still a problem though. We'll see in a couple of days how the building optimization turns out.

[Kankkis]

Originally Posted by BadAim

I'd tend to agree on the vram theory. I have a 1200mb GTX470 and I get good performance with the settings turned down somewhat. The buildings are still a problem though. We'll see in a couple of days how the building optimization turns out.

Or maybe today, Luthier put that information http://www.sukhoi.ru/forum/showthrea...=67866&page=16 saturday and saying testing takes day or two.

Kankkis

[335th_GRAthos]

Thank you Skinny for the great analysis as it helps cover many questions I had.

Indeed, VRAM sees to be the big challenge to solve and I found a nice tool to monitor it:

Finaly after three days of hard work testing the new setup under Win7 I noticed following interesting things
probably worthwhile sharing.

Yes, it is playable but your GPU must have lot's of memory!
Back in Christmas when I was buying my new GTX-570 with 1280Mb RAM I though the Nvidia guys had gone crazy.
I am happy now I kept that thought to myself.

Win7-64bit is a must, otherwise in WinXP you will be stuck to run the game at 640x480 kai 800x600 resolution (maybe also 1024x768 )

Sorry the photos are big because my desktop has 3840x1024 resolution (three monitors) and the game runs in the middle window at 1280x1024.
At the far right are the interesting stats on CPU and GPU workload:

#1 The game appears to be using nicely many CPUs, I have Process Affinity=6 (using cores 1+2 out of the four 0,1,2,3)
the system runs very smoothly and total CPU usage is 30% (whereas WinXP had only 13%).
So, thanks to Win7-64 the CPU doubled, this is good news!
It is a bit surprising though as it conflicts with the statement that the game poorly support multiple-cores.
You will see that the CPU usage is very evenly spread around the four cores, I am also surprised myself.

#2 The less good news is the consumption of GPU memory. The freeware GPU-Z is an excellent way to monitor this in real time.
Here GPU-Z shows the results of the first GTX-570 (the second being idle).
The most important is in the middle of the GPU-Z window, the Memory Used
Above the sea, 1280x1024 Memory Used is 959Mb RAM :excl:
Above land, 1128Mb RAM :excl: :excl:
MY GPU has 1280Gb RAM so it can still run smoothly but if the GPU has less then problems will start and you will have
to lower the resolution or the quality (grass, roads, shadows, etc, etc).

Mission 1, bombers intercept with 12 airplanes in the air


Quick mission over land with 6 airplanes



resolution: 1280x1024
anti aliasing: 0x (I get very bad errors when I try to raise AA)
Epilepsy: Off
Model: high
building: very low
land:medium
forest: off
effects:high
damage decals:high
buildings:low
land shading: low
grass: on
shadows: on
roads: on

I must underline that I am more interesting in flying dogfight than enjoying eye-candy;
The new game has endless capabilities in graphics and it is definitively very heavy for most graphics cards available today
(at least until the next patch arrives) but I do not care that much; if I wanted nice graphics I could have been flying MS FSX four years earlier...
What I find very annoying on the other side though is the unconfirmed information that AI can see through thick clouds
(they had promised us they would fix this in the IL2FB days, it will be a major issue if they did not) -
I can not confirm as I have not tested it yet myself - too busy trimming my rig.

Using GPU-Z you can easily check whether you reached the limits of your system, watching Memory Used and Memory Controller load.
I hope this helps somebody, especialy those who start frustrated "my resolution is 1600x... the game is unplayable" types of threads

~S~

__________________________________________________ ___________
Look also at my post at
http://forum.1cpublishing.eu/showthr...t=19777&page=3
for the performance on 800x and 1024x under WinXP.

[15JG52_Brauer]

I've seen my GPUz memory load go to 1550mb over London. I did some tests myself with CPU clocks from 4.7 down to 2.66 Ghz - only saw 5fps difference (Using London Sightseeing as a test). Have not had time to do more in depth analysis) By the way, what are you using to graph the framerates - is there a tool to grab it from the in game framerate counter or are you using FRAPS benchmark and then manually creating the graphs?

[Skinny]

How could I have missed that. I actually had GPU-z running on my second monitor while benching, mostly to keep an eye on temps and load, I never noticed the "memory used".

Well, if I had any doubts, then I guess that settles it. Thanks for the tip!

As for threading, I wish I could say I agree, but I dont. First of all, you have 4 cores, but you also have hyperthreading, which means 8 cores are exposed to the OS. Each core has the ability to run 2 threads, so its presented as 8 logical cores.

Now by setting affinity mask to 6, you are doing the exact thing you should NOT do, that is pin the threads to 2 logical cores on the same physical core (logical core counting starts with zero). Thats precisely what you need to avoid.

Dont have time for elaborate explanation, but people should leave those affinity mask settings alone if you are using windows 7. You will not gain from it, you will only lose. Windows 7 scheduler is aware of hyperthreading, will not schedule one logical cores sharing physical resources unless all other cores are busy. The only reason to set a mask is if you need one or more cores to be entirely dedicated to another application.

XP is different as it doesnt know about hyperthreading and might therefore schedule 2 heavy threads on the same physical core even if 3 other cores are idle.