An interesting tidbit I found: calculating display memory needs

[WhiteEagle]

Here's how you can determine the memory need of a display, if you ever want to:

If the max resolution is 1280 x 1024; and it can show 16,000,000 colors; the math is:

(1280*1024*32)/(8*1024) = min memory in MB needed

for 64,000 colors, change the 32 to 16; and for only 256, change that number to 8.

[polobunny]

Yes I used this in the Quality vs Quantity ATI Radeon x1950XTX vs Geforce 7950GX2 thread.

I also calculated anti aliasing and triple buffering, while at it. Here's my post:

Originally Posted by polobunny

Exactly what I was thinking. An approach I never saw before. I bet it was rather hard to compare both cards without looking like a fanboy for one of the company.
You have to agree though, 7950 GX2 don't come in very cheap, and the 16X is worth a major lol in my opinion.
Really, think about the buffer needed.

Quick maths for all the HL crew;
1280x1024x32bits = 41,943,040 bits.
41,943,040 bits = 5 megabytes

Now let's add triple buffering, because it just makes vsync better.
5 megabytes x 3 = 15MB

And with different AA's
2X AA = 30MB
4X AA = 60MB
6X AA = 90MB
8X AA = 120MB
16X AA = 240MB

Yep, 16X and triple buffering will take 240MB of your video card ram only for polygon filtering, the textures aren't in yet! And that's the standard resolution for LCD gaming now, let's take something a bit higher, like 1600x1200:
2X AA = 43.95MB
4X AA = 87.89MB
6X AA = 131.84MB
8X AA = 175.78MB
16X AA = 351.56MB

This simply does not make any sense. :P

http://forums.hardwarelogic.com/show...70&postcount=5

[Sovereign]

What about ansiotrophic filtering? If this is true (8xAA requires 120MB of video RAM at 1280x1024) then how does Doom3 run great at Ultra Quality on 512MB 7900GTXs in SLI? I know that there are two of some of the best (note I did not say THE BEST) cards on the market, but if each level requires 500MB of memory and then 120MB is taken away, I don't have 640MB videocards here but my frames are silky smooth, even with 16xAA and 8xSAA + Ultra...

[polobunny]

Anisotropic filtering does not multiply the number. =P
Anti aliasing does, because it samples X times the number of pixels seen on the screen.
2X = 2 times more samples
4X = 4 times more samples
etc etc

I'm not quite sure how you ended with 640MB memory usage. =S

[Sovereign]

Because that's the next real size of videocard memory (supposadly 8800GTS). I hope I didn't imply that it uses that specific amount, because that's not what I meant.