AGP Aperture Size Examined Print E-mail
Written by Kayron James Mercieca and Dan Kennedy
Wednesday, August 28, 2002
Article Index
AGP Aperture Size Examined
Benchmarks
Conclusion

Introduction


Tweak3D prides itself in being one of the few sites online that never says, “Enough is enough.” Our PCs are never fast enough, and we always question how we can make them even faster. We always say, “Hey, what does this setting do?”, or “Hmm, I wonder if my house will burn down if I turn the speed up a little bit.” No, we don’t think there’s such a thing as too much computing power, and our video cards are no exception.

Video cards offer so many features these days that it’s often easy to overlook a couple. Sometimes we might miss important features that are right in front of our eyes, and this is where we came up with the idea to tweak that golden nugget in our BIOS setup, the “AGP Aperture Size”, which from here on out, we’ll refer to as “AAS”.

The Confusion and Mystery Behind AGP Aperture Size

There are many rules of thumb regarding this setting (that we admit, we’re guilty at times of encouraging). But at one point, someone at Tweak3D said, “has anyone tested this recently?” and a silence fell across the lab.
The reason for writing this guide is that many people still ignore the importance of AAS or set it incorrectly. Generally measured in megabytes (MB), AAS is the amount of system memory (RAM) shared with an AGP graphics card in order for it to have more memory to process textures and other visual data.

Some people think that the more RAM you share with the graphics card, the larger the performance boost. In some cases, this might be true. In others, it might result in a performance drop. There are two common outcomes from setting the AAS too high: (1) If you share too much RAM with your graphics card and an application takes advantage of that, you will have less RAM for other functions of the software, and possibly for background applications. (2) If the graphics card does not utilize the memory, it is not taken from system memory. In this case, there are no problems with AAS sucking all of your system RAM, despite its setting in the BIOS configuration utility. The latter is the most common case, since most people have enough memory now to compensate for a high AAS, and most applications would not take all of the memory anyway.

We decided to test the actual performance of the different AAS values to see if (other than available system memory), it affected performance and system stability.

 The AAS setting is located in your BIOS setup from your motherboard. To access it, while booting up your computer, press the designated key for setup (usually Delete). Here, you will find motherboard settings, including the “AGP Aperture Size”. Warning, changing settings without knowing what they are may cause damage to your system, minor or severe.

 

Testing Equipment and Settings

Note each benchmark was run twice, once with a 32MB SDR (Single Data Rate) memory card and the second time with a 64MB DDR (Double Data Rate) memory card. The goal here was to see the results on different memory types and to compare old and new video chips. Here are the details of each card:
32MB SDR Card: Elsa Erazor III Pro 32MB SDR AGP
64MB DDR Card: Leadtek WinFast GeForce3 Ti500 TD 64MB DDR AGP

The rest of the system was kept constant and so, producing a fair test:

CPU: AMD Athlon 1200MHz (266MHz FSB)
Motherboard: Epox EP-8KTA3+
RAM: 512MB 133MHz SDR SDRAM
Screen Refresh Rate: 75Hz
AGP Mode: X4
AGP Fastwrites: Enabled

This test was not conducted to compare these two graphics cards. All settings were kept constant for each graphics card in order to achieve a fair setting for each type of card. However, due to limitations in the TNT2 Pro’s feature set, some settings had to differ.

3DMark 2001 settings (TNT2 Pro):
Resolution and Colour Depth: 1024x768x32bpp
Anti-aliasing: None
Frame Buffer: Triple
Texture Format: 32 bit
Z-Buffer Depth: 24 bit
Rendering Pipeline: D3D Software T&L

3DMark 2001 settings (GeForce3 Ti500):
Resolution and Colour Depth: 1024x768x32bpp
Anti-aliasing: 4 samples
Frame Buffer: Triple
Texture Format: Compressed
Z-Buffer Depth: 24 bit
Rendering Pipeline: D3D Hardware T&L

We also tested “Z II – Steel Soldiers”.

Z II - Steel Soldiers settings (TNT2 Pro):
Resolution and Colour Depth: 1024x768x32bpp
Texture Format: 32 bit
Details Enabled: All (except anti-aliasing – hardware limitation) including mip-mapping, lightmap lighting, etc.

Z II - Steel Soldiers settings (GeForce3 Ti500):
Resolution and Colour Depth: 1024x768x32bpp
Texture Format: 32 bit
Details Enabled: All available details

  


Last Updated ( Monday, May 08, 2006 at 12:00AM )