quote:Original post by Luke Philpot
Does Quake 3 work with your new card?

Your best bet would be to NOT use Cg and rather use HLSL or ARB_vp/ARB_fp. You''ll get better speed on your Radeon if you don''t use Cg (apparently NVIDIA has put in lots of unneeded calls in the Cg code that their drivers filter out, but it really slows down ATI cards... or so I heard )

Hmm, is that true?

@ph33r:
>>Ugg, why is this so difficult?
usually it''s not that difficult - it seems that your situation/machine is something like special case (for all of use)


@Sunray:
>>Hmm, is that true?
yes, i have read this several times in the last couple of days; in other threads too. it logical, that nvidia would do something like this - if you were the boss of nvidia, you would do the same to swear-on everyone on you technique/hardware.




DJSnow
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this post is manually created and therefore legally valid without a signature

quote:Original post by Sunray
Hmm, is that true?

No, it''s not.

The output is not as well optimized as for nVidia targets, that''s obvious. But it''s not true that they are intentionally sabotaging the output for ATI. This rumor came up with the 9700 series, which didn''t support a certain type of swizzle/masking combination in the GPU. The GFFx did. So logically, Cg compiled operations of this type into a single native command on an nVidia card, but into several (going over a temporary) on 9700 cards. That''s not nVidias fault, but simply an unsupported feature on ATI chipsets. There might have been better way to optimize code for specifically that chipset, but its not really nVidias job to optimize their language for the competitions products. Cg is open source, ATI could''ve just downloaded it, and fixed the problem themselves.

But anyway, the 9800 and above support the critical operation in hardware, and will get the same output as nVidias cards.

if your using dx9 just go with HLSL, it was developed parallel to CG and it pretty much the same...

in my opinion... if you''re going with Nvidia then use Cg and the related tools, but if you''ve got an ATI then stick with RenderMonkey.

This is entirely subjective I know, but I see ATI''s tools as far far more professional than Nvidia''s.. I dunno, but I just don''t get the "helpful" vibe from either their website or support dept. I''ve read most of the tutorials ATI put out, and everytime I had a question/problem and emailed devrel@ati I got a reasonable reply within 2 days.

quote:the only bad thing with ATI cards is that the drivers are not as good as nvidia''s one

not 100% sure on this one, but haven''t all the ''leet benchmarkers/hardware freeks been running round in circles shouting at each other about how nvidia''s drivers keep doing silly things to retail games (that ATI dont)? (missing effects/optimization stuff?!)

Jack,

PS - in case you hadn''t guessed, I am unashamedly an ATI fanboy. Too many bad experiences on the FX cards/recent drivers pushed me to ATI, and haven''t been happier since



DirectX 4 VB: All you need for multimedia programming in Visual Basic
Formula 1 Championship Manager, My Game Project.

While we appear to be comparing shader programming on the ati and nvidia hardware, I have a question ...

If you were going to program a ray tracer on the GPU which card would you buy to do it on? I believe Nvidia supports extra instructions and better flow control than the 9800, such as call/ret which could make the programming easier. However Ati seems to be the faster of the two when it comes to shaders.

I have no experience of PC shader programming, though I have worked with the PS2 VU's. Could anyone point me towards any good HLSL tutorials or pages with detailed comparisons between ati/nvidia capabilities in this area.

Basically im a little unsure which card to buy to help me learn directx9 shaders and implement my ray tracer.

Regards
McDusty

[edited by - McDusty on November 8, 2003 1:46:37 PM]

quote:Original post by Crazy_Vasey
I've heard of a bug in Catalyst 3.9 which can prevent OpenGL from working. If you look on the ATI site, there should be a hotfix for it. There's also something on rage3d.com somewhere. Hope that helps.

Hmm, for me OpenGL works fine, but Direct3D dosent. :-)

[edited by - sunray on November 9, 2003 2:25:13 PM]