Tweak3D - Your Freakin' Tweakin' Source!
16-bit vs. 32-bit rendering

Posted: June 25, 1999
Written by: Dan "Tweak Monkey" Kennedy

This short article was only written to demonstrate the worth of 32-bit rendering. Is the image quality difference while using 32-bit color worth the massive performance hit? Read on to find out...

Note: Images may suffer slightly from compression. Click all thumbnails for a 1024x768 screenshot. All descriptions are my opinions only!

Test System:
  • Pentium II 450 CPU
  • ABIT BX6 motherboard
  • Creative Labs Sound Blaster Live! OEM
  • 128 MB PC100 SDRAM
  • TNT2 Ultra reference board using Detonator drivers v1.88
  • All settings on high
  • All default effects (e.g. dynamic lighting) enabled
  • Resolution at 1024x768


Q3Test supports 32-bit color among tons of other options, so it is a good program to use for screenshot comparisons. For each image, there is a 16-bit, a 32-bit, and a split (16-bit on the left, 32-bit on the right) version. For the best comparison, I suggest viewing the split image. It's also helpful to view each image separately to analyze differences. This is not considered an official 16-bit vs. 32-bit rendering comparison, but this is a REAL application of rendering that most people can comprehend.

Q3Test Settings:
  • Default OpenGL
  • Brightness set to 1.20
  • Trilinear filtering enabled
  • For 16-bit: 16-bit texture quality and 16-bit color depth
  • For 32-bit: 32-bit texture quality and 32-bit color depth

Images are split in half. The left side is in 16-bit color, right side in 32-bit color.

Click to enlarge

The most noticeable difference in this image in my opinion is the white ring. Look at it carefully and you should realize that the right (32-bit) side is more clear and better defined. The left (16-bit) side is blurry and fuzzy in comparison.

Click to enlarge

I believe that it's very hard to make any distinction between the two color depths in this picture. There is no real benefit to using 32-bit color in this scene.

Click to enlarge

Although it's rather difficult to see without zooming in (click here to see a zoomed-in portion), there is a major difference between the quad damage "glow" that surrounds the player. On the left, the image is more pixelated and grainy. On the right, it's very smooth. But when not zoomed in, this is very hard to see.

Click to enlarge

The smoke effects are definitely much more impressive when using 32-bit color. Instead of a terrible, grainy green color, the smoke is realistic and smooth. The color looks much better and it separates into layers properly like actual smoke... resembling a cloud. However, this could be a driver issue, and is only really noticeable when you shoot a rocket straight forward without moving.

Click to enlarge

This image shows many benefits of 32-bit color. First and most obvious, the circle of light from the rocket is very clear as opposed to grainy. This creates a smooth sphere of light. There are a few other really obvious differences as well. The rocket looks more smooth and realistic in the 32-bit color image. The side lights (just above the left and right portals) look more like spheres of light with 32-bit color. Nothing to do with color depth: the bouncing pads in the middle have an extra ring of orange (which blinks on and off)... sorry for not realizing that right away.

With Q3Test, the image quality is definitely in the favor of 32-bit rendering. I suggest enabling 32-bit rendering if your video card supports this feature and you have the frame rate to spare. I highly recommend that you use a lower resolution and graphic detail to ensure a high framerate. In fact, if using 32-bit color means the difference between using a certain resolution or not, I recommend keeping 16-bit enabled.

Need for Speed: High Stakes

NFS: High Stakes isn't a game that supports a lot of new hardware features, but it does have 32-bit rendering support, so I decided to test it out. You can enable 32-bit rendering by choosing Options, Graphic Options, Resolution, and selecting 1024x768x32 (or your desired resolution).

NFS: High Stakes settings:
  • All details set to High.
  • For 16-bit: Resolution set to 1024x768x16
  • For 32-bit: Resolution set to 1024x768x32

Click to enlarge

The difference is very hard to see. I personally cannot tell the difference between 16-bit and 32-bit in this picture, except for the textures on the street. The cars and background as well as the extra objects look almost identical.

Click to enlarge

This zoomed-in image of "La Nina" should reveal that there are a few advantages to using 32-bit color with this game. The 32-bit shading is smooth and consistent, unlike the blocky, unorganized 16-bit shading. Also, the window is less cloudy and looks more like actual glass. One other advantage is the smoke that comes from burning up the tires. I tried taking screenshots of this but it was rather difficult. Other than these points, 32-bit color offers few advantages.

With NFS: High Stakes, the 32-bit image quality is slightly noticeable. I do not recommend using it because the performance hit outweighs the visual benefit.


Is there a clear winner between 16-bit and 32-bit rendering? In my opinion, no... not at this time, and there won't be until all games that utilize 32-bit rendering actually offer sufficient graphical improvement to warrant the performance hit. The visual quality is definitely more impressive when playing Q3Test, but not in all areas. Some items in the game clearly look better, while others look almost the same. Are these extra features worth a massive hit to your frame rate? Sure, if you have the performance to spare... but not everyone does.

My P2 450 / TNT2 Ultra system running Q3Test at 1024x768x16bpp has relatively no performance issues: the game runs great. Occasionally the frame rate drops to about 30, but for the most part it stays well over that and runs smooth. However, when using 32-bit color, even 800x600 drops below 30 FPS when there is plenty of action on the screen. And there's no way I'm going to resort to using 640x480x32bpp just to ensure that I'll always have 30 FPS. At this point, 1024x768x16bpp seems much more appealing. When playing a fast paced game like Q3Test, I care much more about the frame rate and resolution than the image quality, and I'm certain that plenty of readers agree with me on this issue.

Also, most games that people are playing in 32-bit color show almost no visual benefit. Many people play Quake2 with 32-bit color even though screenshots and actual play show no real advantage, even with the a large performance hit. Need more games? How about NFS: High Stakes? The visual quality difference is almost negligible. When you're racing and trying to watch every turn, do you look at a waterfall (while driving by, doing 160) and say to yourself "Boy, I sure am glad I lost 20 FPS to make that waterfall slightly prettier"... most likely not.

I'm not saying that everyone should run their games in 16-bit color. In fact, I encourage people to try 32-bit color. There are definitely plenty of games that look great in 32-bit color (Expendable comes to mind). Just make sure to analyze the details yourself, to ensure that you're not suffering through the drudgery of 20 FPS simply because you think 32-bit color looks twice as good as 16-bit color.

Hopefully, developers of software (and hardware) will find a way to improve 32-bit rendering in the future, so that we will have more reasons to use it (and want to use it) with more games. In the meantime, I'll stick to 16-bit color for most of my games. Thanks for reading!

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