Graphics aperture size....

[GSXdan]

What is this exactly and what should it be set at? I have a Radeon 9500 Pro(128mb DDR) and the aperture size is set at 64mb.

thanks ^dan

[avx]

Graphics Aperture: Pertains to any computer device or program that makes a computer capable of displaying and manipulating pictures. For example, laser printers and plotters are graphics devices because they permit the computer to output pictures. A graphics monitor is a display monitor that can display pictures. A graphics board (or graphics card) is a printed circuit board that, when installed in a computer, permits the computer to display pictures.
Many software applications include graphics components. Such programs are said to support graphics. For example, certain word processors support graphics because they let you draw or import pictures. All CAD/CAM systems support graphics. Some database management systems and spreadsheet programs support graphics because they let you display data in the form of graphs and charts. Such applications are often referred to as business graphics.

What should it be set at: The aperture is a portion of the PCI memory address range dedicated as graphics memory address space. Host cycles that hit the aperture range are forwarded to the AGP without need for translation. This size also determines the maximum amount of system RAM that can be allocated to the graphics card for texture storage.

AGP Aperture size is set by the formula : maximum usable AGP memory size x 2 plus 12MB. That means that usable AGP memory size is less than half of the AGP aperture size. That's because the system needs AGP memory (uncached) plus an equal amount of write combined memory area and an additional 12MB for virtual addressing. This is address space, not physical memory used. The physical memory is allocated and released as needed only when Direct3D makes a "create non-local surface" call.

Win95 (with VGARTD.VXD) and Win98 use a "waterfall effect". Surfaces are created first in local memory. When that memory is full, surface creation spills over into AGP memory and then system memory. So, memory usage is automatically optimized for each application. AGP and system memory are not used unless absolutely necessary.

The size of the aperture does not correspond to performance so increasing it to gargantuan proportions will not improve performance. Many graphics card, however, will require a larger than 8MB AGP aperture size to work properly so you will need to set a minimum of 16MB for the AGP aperture size. Even then, you should set the aperture size at a higher setting so that it will be large enough to accommodate any texture storage requirements that your games/applications may have.

At the moment, the rule of the thumb is an AGP aperture size of about 64MB to 128MB. Increasing the AGP aperture size beyond 128MB wouldn't really hurt performance but it would still be best to keep the aperture size to about 64MB-128MB so that the GART table won't be too large. As the amount of onboard RAM increases and texture compression becomes commonplace, there's less of a need for the AGP aperture size to increase beyond 64MB. So, it's recommended that you set the AGP Aperture Size as 64MB or at most, 128MB."

I found the definition using www.webopedia.com and this article at http://www.experts-exchange.com/Hard..._20031947.html

Hope that helps you understand it, helped me some too thanks

avx

[glc]

A rougher rule of thumb is set it to 1/2 of your installed system memory or 128mb, whichever is less.

[GSXdan]

I found that increasing it to 128mb decreased my performance. with - check specs - and aperture size set to 128mb, gameplay lagged a few times, but when i changed it back to 64mb it was fine...

thanks for the info ^dan

[Force Flow]

Here's a discussion on the same topic that we were having over in the hardware forum: http://forum.pcmech.com/showthread.p...threadid=54950