Can you read?The difference is not more than 10%. Barefeat ran tests using Quake 4, Doom 3, WoW, Halo, Prey among others with 1920 x 1200 and found 9% difference at the most.
http://www.barefeats.com/rosa03.html
<Hagge> Doom 3 at 1440x900 High Quality , FSAA = 4X
<Hagge> 128M = 21 fps
<Hagge> 256M = 26 fps (or 24% advantage)
<Hagge> Doom 3 at 1440x900 Ultra Quality, no FSAA
<Hagge> 128M = 16 fps
<Hagge> 256M = 46 fps (or 188% advantage)
Ok, notice how Ultra quality (large textures) makes the 128MB slower than 4x AA, the 256MB versions gets faster with large textures but no AA instead. Why? Because AA uses gpu power but textures vram.
16 fps vs 46 fps at 1440x900 ultra quality is 188% faster, not 10%
<Hagge> Quake 4 at 1440x900 High Quality, FSAA = 4X
<Hagge> 128M = 23 fps
<Hagge> 256M = 38 fps (or 65% advantage)
<Hagge> Quake 4 at 1440x900 Ultra Quality, no FSAA
<Hagge> 128M = 4 fps
<Hagge> 256M = 37 fps (or 825% advantage)
Even worse in Quake 4 (newer game than Doom 3, same engine.)
128 MB have no chance in hell to handle ultra quality textures here, 256MB is just as happy with larger textures as 4x AA. 825% faster!
Not that 825% faster means much, since 128MB is unplayable on these settings, just play it in 1024x768 high instead. Without AA and AF. And difference will be much smaller.
<Hagge> galet
source:
<Hagge> http://www.insidemacgames.com/forum...334&st=160#
<Hagge> Under Windows XP Pro, I ran 3DMark06 at 1440x900, 4X FSAA, 4X Anisotropic Filtering:
<Hagge> SM2.0 Gaming
<Hagge> 128M = 641 rating
<Hagge> 256M = 1279 rating (or 100% faster)
<Hagge> HDR/SM3.0 Gaming
<Hagge> 128M = 554 rating
<Hagge> 256M = 1063 rating (or 92% faster)
Notice how 3dmark06s gaming benchmarks for SM2 and SM3+HDR are 92-100% faster with 256MB vram. But here the settings when benchmarked where 1440x900 with 4x AA and 4x AF. Those needs more vram aswell and therefor it gets faster. Without AA and AF and eventually at lower res differences would be much smaller.
<Hagge> Under Windows XP Pro, I ran Prey 1.3 at 1440x900, 4X FSAA, 4X Anisotropic Filtering:
<Hagge> 128M = 31 fps
<Hagge> 256M = 46 fps (or 48% faster)
Not that I need AA, and to less extent AF (but AF is nice), but both cards seems to handle Prey at 1440x900 in XP nice, but the 256MB version runs it 48% faster.
<Hagge> tror inte 3dmarkvärdena verkligen är överförbara till fps dock
<Hagge> och man kan ju skita i att köra med aa o af
<Hagge> http://www.insidemacgames.com/forum...334&st=160#
<Hagge> http://www.insidemacgames.com/forum...mp;#entry315638
<Hagge> fast spel som kräver 256MB vram kommer ju vara för långsamma på en sådan gpu hur som helst
<Hagge> http://www.insidemacgames.com/forum...334&st=180#
<Hagge> I ran Prey on both the 15" MacBook Pro 2.2GHz (128M VRAM) and 15" MaBook Pro 2.4GHz (256M VRAM). The settings were High Quality, 1440x900, 4X Anti Aliasing, and 4X Anisotropic Filter.
<Hagge> Under Mac OS X, the unit with 256M of VRAM was 3% faster (21.5 fps vs 20.9 fps).
<Hagge> Under Windows XP Pro, the unit with 256M of VRAM was 54% faster (46.2 fps vs 29.9 fps).
Notice here how much faster this game is in XP than OS X, with 128MB vram it's 20.9 fps in OS X vs 29.9 FPS in XP. With 256MB vram it's 21.5 fps in OS X (barely noticable) vs 46.2 fps in XP. That means that prey run 54% faster on 256MB vram version in XP! (But only 3% faster in OS X.)
I would guess this is because XPs OpenGL are better and uses more of the graphics card, and that it therefor makes a bigger difference how good it is.
Anyway if you play at a setting which uses not as good looking textures and skip AA and AF (demanding games won't run at decent rates in 1440x900 anyway so it's better to try to use high res than use such functions anyway) it will probably not matter so much. But if you want to have the best experience, run full res and raise the settings the 256MB version is definitly better.
I hate how apple spares tens of bucks to force people to get the much more expensive version. I guess it's because they are in bed with Intel and Intel wants them to sell more high end CPUs.
(I'm Hagge btw, I pasted this for a friend on IRC.)
Edit:
http://www.hardforum.com/showthread.php?t=968115
Argues that people can't even see the difference of high and ultra quality textures.
But I guess some other games might use large textures aswell, the question is if they will use scenes which are to heavy to render for the 8600m GT anyway.
I still don't know what to choose, and I think I can change my mind on monday.
But still I hate Apple so much for doing this. Forcing me to pick a crappy modell just because they want to sell their überexpensive CPU. We shouldn't have to choose, 256MB should be the default in all modells.