FX series - DX9 or not?

[jedcred]

I have a FX 5600 Ultra, and I bought it thinking that it was DX9 compatible and all that. However, especially on the Steam forums in regards to Half-Life 2, people mention that Nvida "dropped the ball on the FX series" and "FXs don't do DX9". I have this experience with HL2, where the game insists on being run through the DX8 path. I seemed to have missed something. What's going on?

 

[rbV5]

FX series cards are definately DX9 hardware with comparetively poor shader support. It likely uses the DX8 path for performance reasons.

It doesn't matter what someone "says" anyway, play your game and enjoy it...you can see for yourself if its acceptable or not. The best you can do is research your purchase well before spending your hard-earned money (I don't recall the 5600 ultra ever being a value/performance buy) but once you have it, you may as well enjoy it, if not...get rid of it.

 

[vshah]

the FX series has full support for dx9. meaning if you want to run any dx 9 app, they will run it. however their dx 9 pixel shaders are very slow. for that reason, games choose the dx8.1 codepath to preserve playable framerates. if you wanted to force the dx9 codepath in hl2, you could do it, and it would look fine, but the performance would be crappy.

-Vivan

 

[BFG10K]

The FX series is DX9 compliant but it runs SM 2.0 shaders extremely poorly.

 

[Gamingphreek]

Originally posted by: vshah
the FX series has full support for dx9. meaning if you want to run any dx 9 app, they will run it. however their dx 9 pixel shaders are very slow. for that reason, a game (only one game does this) choose the dx8.1 codepath to preserve playable framerates. if you wanted to force the dx9 codepath in hl2, you could do it, and it would look fine, but the performance would be crappy.

-Vivan

fixed 🙂

 

[vshah]

Originally posted by: Gamingphreek

Originally posted by: vshah
the FX series has full support for dx9. meaning if you want to run any dx 9 app, they will run it. however their dx 9 pixel shaders are very slow. for that reason, a game (only one game does this) choose the dx8.1 codepath to preserve playable framerates. if you wanted to force the dx9 codepath in hl2, you could do it, and it would look fine, but the performance would be crappy.

-Vivan

fixed 🙂

true 😀 probably more in the future though. some will, some won't. it will be specific to each game's graphical demands, even if they use the same (source) engine.

 

[stnicralisk]

should have bought a dell 😛

 

[jedcred]

Thanks very much, but only buy Dell if you're willing to go to Hell: that's what they say. Actually, about the value thing, I was a able to get this at Thanksgiving last year for $99 at Compusa after rebates (with Splinter Cell packed in), so I guess it wasn't all that bad. However, one interesting thing is that it uses the DX8 path instead of the DX8.1 path. Not that it makes much difference, but apparently the Ti4200 (which my brother has now) has the FX 5600 beat in DX8 tests.

I mean, at the time, the FX 5900 (no 5950) was something like $350, no PCIe, and the FX 5600 was a mid-range Ultra at around $100.

 

[nitromullet]

There was a post about a DX8 reflection patch that made the DX8 codepath look considerably better. You might be intersted...

http://forums.anandtech.com/me...8240&enterthread=y

and this one on how to force FP16 in DX9 for FX series cards that will increase your performance, but may reduce IQ in some instances. You might also be interested in that...

http://forums.anandtech.com/me...;threadid=1454040&