128 Mb vs 256 Mb debate

[Xilikon]

I have found a few debate on 128 Mb vs 256 Mb but none has a very clear explanation. I decided to make a new one and formulate a better question to help me make a better decision

I know video card memory is mostly used to store textures. I wanted to know at what resolution/quality settings we start to overflow the 128 Mb area, thus making 256 Mb video cards a better choice. Doom 3 or FarCry would be a good choice as those game is very heavy on the video cards.

I plan to buy a LCD screen and most of them run at 1280x1024 by default so it is pointless to run the games at 1600x1200. Having a LCD screen can alleviate the need of more memory and save money on the graphics card (this is the last nail to hit for my decision between 6800NU/6800GT and i'm not very keen of FPS games but wanted to make it usable for a long time).

 

[tranCendenZ]

What you read is true, but Doom3 has provisions for that - Medium Quality mode, which uses more compressed textures than High Quality (256mb) mode. Then there is Ultra Quality (512mb) mode that uses completely uncompressed textures, and cards that truly run this mode well aren't even available yet.

i.e. - with a very fast cpu (FX53), you'd probably run something like this for no slowdown/completely smooth gameplay

Doom3
6800NU - 1600x1200 0xAA/8xAF @ Medium Quality
6800GT - 1600x1200 2xAA/8xAF @ High Quality
6800U - 1600x1200 4xAA/8xAF @ High Quality
6800NU - 1280x1024 2xAA/8xAF @ Medium Quality
6800GT - 1280x1024 4xAA/8xAF @ High Quality
6800U - 1280x1024 4xAA/8xAF @ High Quality

FarCry
6800NU - 1600x1200 2xAA/4xAF (higest quality water effect off)
6800GT - 1600x1200 4xAA/8xAF (max effects)
6800U - 1600x1200 4xAA/8xAF (max effects)
6800NU - 1280x1024 2xAA/8xAF (higest quality water effect off)
6800GT - 1280x1024 4xAA/8xAF (max effects)
6800U - 1280x1024 4xAA/8xAF (max effects)


with a more mainstream cpu (p4 3.0ghz), you'd probably run something like this for no slowdown/completely smooth gameplay

Doom3
6800NU - 1600x1200 0xAA/8xAF @ Medium Quality
6800GT - 1600x1200 0xAA/8xAF @ High Quality
6800U - 1600x1200 2xAA/8xAF @ High Quality
6800NU - 1280x1024 0xAA/8xAF @ Medium Quality
6800GT - 1280x1024 2xAA/8xAF @ High Quality
6800U - 1280x1024 4xAA/8xAF @ High Quality


FarCry
6800NU - 1600x1200 0xAA/4xAF (highest quality water effect off)
6800GT - 1600x1200 2xAA/8xAF (max effects)
6800U - 1600x1200 4xAA/8xAF (max effects)
6800NU - 1280x1024 0xAA/8xAF (highest quality water effect off)
6800GT - 1280x1024 4xAA/8xAF (max effects)
6800U - 1280x1024 4xAA/8xAF (max effects)


Note that you might be able to turn up the quality higher in Doom3, but it could result in hitching as the memory gets overflowed as you call it.

It boils down to this; there is a good performance gain between the 6800NU and 6800GT even if the game doesn't use 256mb of textures. The 6800NU is 325/700 12x1, while the 6800GT is 350/1000 16x1, so even without the extra memory there will be a big performance boost.

That being said, Doom3 will run fine on a 6800NU as HardOCP pointed out, as will most other games. You will likely just have to turn off a few details possibly, or run with less AA/AF. If you want highest details AA/AF, go with a 6800GT/6800U. If you don't mind not having everything maxed, the 6800NU works fine too. Its really about how much the $100 means to you. If it means that you have to live like crap for a month, buy the 6800NU. If you have $100 floating around to burn, buy the 6800GT.

 

[Wolf-R1]

But the effects don't have as much to do with video memory allocation as textures to. Doom3 textures uncompressed are roughly 512MBs...which is why Ultra quality gives that warning before letting you change to it.

The effects have more to do with the GPU itself.

 

[tranCendenZ]

But the effects don't have as much to do with video memory allocation as textures to. Doom3 textures uncompressed are roughly 512MBs...which is why Ultra quality gives that warning before letting you change to it.

The effects have more to do with the GPU itself.

Right, but my point is 6800nu has both less memory and a less powerful GPU, not just less memory. So you will likely have to reduce both effects/aa/af & texture load when trying to match framerates with a 6800GT.