Friday, 30 May 2014

WarThunder - OpenGL Performance Discussed

In the final of my series regarding WarThunder this week, I've taken a look at the performance of the OpenGL rendering options.

I've tried this on two machines, with different graphics cards, but very similar specifications otherwise, the two machines are:

Core i7 - 950 - 3.07Ghz
16GB 1600Mhz DDR3 RAM
NVidia GeForce 260 GTX 896MB DDR3

Core i7 - 3770 - 3.01Ghz
8GB 1600Mhz DDR3 RAM
Nvidia GeForce 540 2GB DDR5

Clearly one machine has the superior graphics performance on DirectX mode, yes the 540 out does the 260, just... Though my 260 is a really good superclocked edition, so much so its proving hard to find an economical replacement (pushing me to have to buy a 770 GTX just to see a significant improvement).

Most all the screen shots you see of WarThunder on this blog come from the machine with the 260 in it as well.

But so far all the screen shots have been from the Direct3D renderer.

Now, however I'm testing the OpenGL renderer, the option is listed as Test and I've also tried to collaborate my observations with other players... My overall impression is:

Half the FPS, if I got 60fps in a situation in a plane in Direct3D, I'd get 30 in the near same situation in OpenGL.  This is a rough and ready measurement taken by eye from the FPS reading given on screen in the client.

I've purposefully NOT recorded my game play, I've not run other programs nor over reached things - that is I've not thrown clouds of AI aircraft into formation within a custom battle and flown through them.  I've stuck to playing the regular game in the regular way.

Lets take a look at some screen shots:

It looks the same, I've not noticed any surface level differences, the game looks just as good.

Only when one scrutinizes things do you find the differences, if we jump into a cockpit and look around, we can see where in Direct3D we'd get smooth textures things can look quite odd:

This is the seat over my pilot's left shoulder in the Fw190 A1, as you can see there's this square stippling going on, also along the window rail you can see a darker indication that is actually a shadow from the wind shield surround.

This isn't the only odd thing noted, in the 540 card, not on the 260, I took the Fw190 into a twilight flight.  You can change this yourself in your settings under the Graphics options you need to select the Texture type of "Night as Day" (or something like that)...

When I flew the plane out on the 540 GTX, I saw this strange halow effect around the periphery:

The effect persisted against the clouds, from any angle, or against the ground.  But it did not show against clear sky.

Switching back to Direct3D no such halow was present on either card's output.

Performance wise I've already mentioned the lower frame rate, however, at one point during a pursuit in Historical battle in the Me410 I took out an enemy aircraft, with the explosion close I suddenly had a frame rate reduction down to 2FPS.  Literally slide show mode...

I used a little back stick to bring my nose up and came through it, but I'd moved around 1km before the frame rate returned to above 20 and allowed me to have some semblance of control.

I checked my logging, there was no hard drive activity, no appreciable network lag, no dropped packets, I could type into the client and ask "Anyone else getting lag", which was a reply of "nope" from a fair few players.  Yet I was at 2FPS 50 meters off of the hard deck struggling.

The optimisation of the Direct3D code being used by Gaijin is really good, they get performance out of my rigs other less intensive, less pretty, games get... So perhaps we can chalk this massive red blot on the performance of the OpenGL implementation to a lack of development/optimisation and of course the code being "Test".

But, one would assume the Mac client is already using OpenGL, are any Mac players out there able to share their thoughts?

Either way it looks promising that OpenGL does work, and this of course leaves us thinking about Linux/SteamOS.

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