Alexo, it might be helpful if you posted some information about the hardware you’re using as well. Most importantly, what graphics card do you use? CPU and RAM info might come in handy too.
How much VRAM has your graphic card?
This kind of drastic drop normally happens with 256MB of VRAM (on an AAA title, 128MB on a AA and lower title) and less in combination with AntiAlias which raises the VRAM requirements of the basic rendering already considerably (considerably in the sense of 60MB+ instead of basic VRAM usage of around 25MB, only for the backbuffer, front buffer and potential tripple buffer, without any other media loaded)
The other thing that has a drastic impact is a “weak” GPU and using PostRender FX
Full VRAM wouldn’t swap to disk; it would swap to system RAM. You’ve hit some kind of limit here, regardless–either memory or fill rate or whatever else (the 8600M isn’t that beefy of a card).
VRAM is graphics ram. That will never swap to disk.
That will at best swap to regular RAM but the moment that happens it will break down to 10 FPS.
With 128MB you can not use AA and a resolution of 1280x1024 and higher in the same go unless you have a pretty simple game (where you commonly wouldn’t need AA)
the sudden actually is what indicates that it is potentially related to a run out of VRAM which means that it must stop the rendering mid frame to exchange textures in VRAM and upload new ones.
Note that Beautiful and Fantastic have Anti-Aliasing turned on. Especially for that large of screen resolution, AA is going to be very costly to the GPU (especially 4x AA at Fantastic).
Also note that if you have shadows enabled at all, the higher quality shadow settings for Beautiful and Fantastic are also quite expensive to render in real time.
And the Nvidia 8600 M is not that fast, even though it’s a full featured card. The Mobile cards are underclocked, among other things. A super-fast, super-modern desktop grade graphics card with a ton of VRAM on a screaming CPU will be able to handle the AA, but even otherwise capable lower-end cards just won’t.
I would expect if you turn off AA for that quality setting, the resolution will be OK.
I have an iMac (2.4Ghz duo core, 2 gig ram, ATI Radeon 2600 Pro) upstairs that can run half life 2 with 4x AA and full settings at 1920x1200 at 60 fps. That iMac is a decent gaming rig, but doesn’t exactly have “A super-fast, super-modern desktop grade graphics card with a ton of VRAM on a screaming CPU” (actually, my high end graphics card on my Mac Pro only has 256 MB’s of vram).
AA (in Unity at least, I’m happy to say) doesn’t give that much of a performance hit compared to, say, the Cryengine (which gives a MASSIVE performance hit for very little graphics improvement). Either way, an upscale in AA and resolution shouldn’t have anywhere NEAR that much of an impact on performance, and it shouldn’t be hitting the vram as hard as it is.
Not sure why the AA and resolution is sucking up all of your vram, but it sounds bad. Any chance we can get a screen shot of your game and stats window? 128 MB’s vram is plenty for your screen res and AA. I just put my game I’m making on 2560x1600 with 4x AA and used up 140 MB’s of vram. But your resolution is 1280xWhatever and when I tried out that resolution, I only used up 30-40 MB’s of vram.
Anyone know for sure if vram is used by anything other than post effects, AA and screen res? Because this is kind of a weird problem. :?
the GMA chips in mac mini have up to 256MB VRAM shared, thats twice as much as he has.
Use 4x AA on a GPu that is able of MSAA (!= Intel) and you went through the 50-60MB VRAM border already. Does not take much math to calculate how much screen space you have left then ( actually 12 1024x1024 textures uncompressed) till you start kill the performance.
Textures (which can use lots of VRAM depending on how many you have, what compression you’re using, etc.), rendertextures, shadows (since they are texture-based; point light shadows are huge since you need 6) and meshes.
the fps goes NORMAL if we switch to windows (alt-tab) and go back to the app!!!
some scene from 7 to 90 fps
some other from 20 to 180 fps
more…
if I run the app windowed, the FPS stays low even minimizing the window
more…
it seems it happen when we load a scene, but… not every time (i’m going crazy!)
We made a build with only one scene and set a button to reload the scene.
Clicking the button SOMETIMES it reload with the problem and SOMETIMES it doesn’t…
…then ALT-TAB… THE PROBLEM GOES!!!
more…
we are trying to reproduce the phenomenon, but it doesn’t happen always on the same conditions
I use the latest nVidia drivers with default (restored) settings and “let application choose” on 3D settings
ps
I closed all windows apps, services and processes uneeded on background
ps
in the stats window (within the unity editor) the VRAM stays far from 128MB
For the record, i was referring to the GPU in the Santa Rosa MacBook Pro, which is an “OK” but not great gaming chip, and in fact doesn’t have the horse-power to do AA at high frame rates at large screen resolutions.
If the frame rate recovers when you reload the scene, maybe you are spawning a large number of objects or something that are then hogging the GPU/CPU or using up an increasing amount of main memory (not VRAM).
I suggest you profile your OSX runtime with Shark (part of Apple Developer Tools) and see what processes are using all of your system resources.
You didn’t mention whether you see the same behavior (low frame rate or recovery of frame rate) on OSX.
