Graphics 6800's own x800 xt pe

clock speeds on the X800 XT's are far better than the 6800's

surely this makes them better?

better in my eyes

 

This argument is comperable to the Intel/AMD one. Its not better performing due to higher numbers; nor is it better performing period for that matter.

 

The higher clocks make their "theoretical" throughputs, but quite often in games, this is not the case. Doom 3 is based around OpenGL, which is a big weakness in ATI's catalyst drivers... they're in the process of re-writing the OpenGL side of their drivers in order to play catch up with NVIDIA in the largest title of the last two years (and most likely larger than Half-Life 2).

The theoretical fill-rate that the X800XT can output is (16x520) = 8320 Mpixels/sec, whereas the 6800Ultra can output upwards of (16x400) = 6400 Mpixels/sec (there are many variances in retail 6800 Ultra clock speeds, though)...

From looking at the HardOCP guide, you can see that the theoretical fill-rates don't mean an awful lot, only what the card/chip is capable of... this proves that having good drivers is an important part of the while package. ATI have a complete re-write in progress, and only time will tell with respect to what we can expect to get from an ATI board in Doom 3.

 

The HL2 guys have really wounded themselves with endless waiting and broken promises (if not downright lies). I'm sure ATI were none too happy with them. Now that we will have Farcry and DoomIII a lot of the cherry has gone for HL2, along with the interest and anticipation (IMHO).

Another factor in 'X800 series VS 6800 series' is CPU power, it seems these cards have a lot of potential that they simply can't fully demonstrate yet, so along with all the other factors I think we'll really have to wait for CPUs and mobos to play 'catch up'. It sure is close though, apart from OpenGL and esp Linux that is.

Bigz, I was curious if you had any idea how 9700Pro would fair in Doom III if not up-coming DX9 games in general. The main reason is that the 9700 series' pixel shader instruction length (PSIL) is just 64 and without the hw F-buffer of the 9800 series it's a hard limit. The 9800 series improves little over the 9700 series except for a big increase in PSIL from 64 to 160 and the addition of F-buffer which can still step in when the limit is breached. At least that's as I understand it all. Other ref points of DX9 cards' PSIL is GF-FX = 1024 and X800 series = 1536. I seem to rem Carmack saying most cards' PSIL is overkill yet I can't help wondering if ATI were too stingy with PSIL on the 9700 series and nowhere seems to really touch on it.

 

I'm not 100% sure, but I would imagine you'd be able to play at around 1024x768 with medium quality, dependant on CPU speed.