XFX GeForce 7900 GT 256MB PCI-E XXX Edition

Reviews: Hardware

Motherboards | Power Supplies | Memory | Systems | Video Cards

XFX GeForce 7900 GT 256MB PCI-E XXX Edition

Author:
Editor:
Sponsor:
Published:

Kurtis Kronk
Brian
XFX
Jun. 8, 2006

<< Previous

Next >>

The HDR+AA Fiasco

Before I get to the performance of this card, I'd like to address an issue with this and every other 7x00 card on the market. If you haven't already heard about the HDR (High Dynamic Range) + AA (AntiAliasing) fiasco, here's the story... NVIDIA was the first to adopt Shader Model 3.0 (SM3.0) with their 6 series of cards, while ATI didn't adopt SM3.0 until their X1000 series launched. HDR lighting is a feature in some of the newer games which helps to create a more realistic environment, and SM3.0 support is needed for HDR to work. You may recall the times when NVIDIA would call out ATI for not adopting SM3.0 earlier, but then when ATI finally did, they touted their implementation as "SM3.0 done right." I won't go into detail about how each of their implementations differ, but what you need to know is that NVIDIA's implementation does not allow you to enable AA while you have HDR enabled - most of the time at least.

For example, Half-Life 2 (Lost Coast and Counter-Strike: Source's CS_Militia map use HDR) has an unusual way of going about HDR, and you will have no problems using HDR and AA simultaneously in this game where it is supported. I was personally told by ATI representatives that NVIDIA's cards couldn't run Black & White 2 with AA, but when I checked for myself, I found that I could. I believe this is because Black & White 2 doesn't actually use HDR, but instead just uses blooming for the desired effects, but I'm not 100% sure if this game actually does have HDR or not - either way, AA works and ATI was wrong. Need for Speed Most Wanted doesn't use HDR (just bloom effects), so AA does work in that game on NVIDIA's cards. Splinter Cell Chaos Theory will not allow you to enable HDR and AA simultaneously, and if you try to bypass the system and enable AA in the NVIDIA control panel, you'll end up seeing artifacts in-game (more details on this in my upcoming Image Quality article). I gave Far Cry to my little brother because we don't use it for benchmarking anymore, so I can't verify this, but what I hear is that you can not enable HDR and AA at the same time in this game either. Another game that won't run HDR+AA on NVIDIA cards is the recently released Elder Scrolls IV: Oblivion. Apparently HDR+AA doesn't work in this game on ATI cards either, but ATI has released a patch that bypasses the game's settings, allowing you to enable HDR and AA at the same time.

At the end of the day, whether or not the HDR+AA issue will affect you depends on what games you play and whether or not you care. If you play at higher resolutions such as 1600x1200, then the lack of AA might not bother you much. My personal feeling is that this is a big booboo for NVIDIA. They've got an entire generation of cards that are plagued, albeit in a small way, by arguably inferior image quality in those games where you can't run HDR and AA simultaneously. I've been told that NVIDIA will address this issue in their 8x00 series of cards, so if this is a deal breaker for you, either buy ATI now or wait for the next generation of cards to roll around.

Keep your eyes peeled for my image quality article in the next week or two where I will discuss this issue more in-depth as well as compare image quality between ATI's Radeon X1000 series and NVIDIA's GeForce 7x00 series. I'll cover all of the various AA and AF modes including Adaptive AA vs. Transparency AA, MultiSampling vs. SuperSampling, High Quality AF, and more. I'll also be examining the performance penalty incurred in a few games with some of these advanced settings to see show image quality in conjunction with playability. After all, who cares if you've got settings that produce the best image quality if the performance is unbearable.

We'd like to thank Directron.com for donating the ASUS A8N-SLI Premium Socket 939 Motherboard which we used for testing.

<< Previous

Page 3 of 16

Next >>

Page 1: Introduction
Page 2: The Card & Bundle
Page 3: The HDR+AA Fiasco
Page 4: Test Setup
Page 5: Benchmarks: Half-Life 2
Page 6: Benchmarks: Splinter Cell Chaos Theory
Page 7: Benchmarks: Quake 4
Page 8: Benchmarks: X3 Reunion Demo
Page 9: Benchmarks: Chronicles of Riddick
Page 10: Benchmarks: F.E.A.R.
Page 11: Benchmarks: Need for Speed Most Wanted
Page 12: Benchmarks: Black & White 2
Page 13: Benchmarks: 3DMark '06
Page 14: Overclocking... and Underclocking?
Page 15: Performance Summary
Page 16: Conclusion

Subscribe to Video Cards [more info]

Add Comment

1 User Comment

1 - Posted by Kurtis on June 8, 2006 - 3:48 pm

I've updated this review. (See conclusion)

Add Comment

To add a comment without being a member, you may omit the password field, but you must enter your name (or nickname) along with your comment. * Denotes required fields.