What are AGP Fast Writes?

[MisterRaven]

I was having problems with my ATI Radeon 9800np before I disabled AGP Fast Writes, and I was told not only that it should be disabled for ATI cards, but also that it won't affect performance.

My question is this: What exactly are AGP Fast Writes? What do they do? And if they don't affect performance, then what the hell are they doing as an option in my BIOS?

Thanks in advance.

 

[sugarkang]

wow. i was told the exact opposite.
that you'd have to enable them to get kicka55 scores in whatever benchmark.

 

[Mem]

Fast writes allow the process to send certain graphics calls directly to the video card, thus bypassing the system memory and reducing system bandwidth usage. Several popular cards, especially from nVidia, support this option. Recommended setting is enabled if supported, assuming no video related stability problems exist.

For maximum stability fastwrites are best disabled,having fastwrites on can cause stability problems on some systems and even then the speed increase is very small,infact some systems can be slower with fastwrites on.

 

[MisterRaven]

Originally posted by: Mem

Fast writes allow the process to send certain graphics calls directly to the video card, thus bypassing the system memory and reducing system bandwidth usage. Several popular cards, especially from nVidia, support this option. Recommended setting is enabled if supported, assuming no video related stability problems exist.

For maximum stability fastwrites are best disabled,having fastwrites on can cause stability problems on some systems and even then the speed increase is very small,infact some systems can be slower with fastwrites on.

Okay, thanks.

Education feels good.

 

[jiffylube1024]

It's so weird though, Fast Writes works fine one some machines. I had it on for my 9800np on both an IC7 (intel 875P chipset) and A7N8X-X (Nforce2) and had zero problems.

 

[MisterRaven]

Originally posted by: jiffylube1024
It's so weird though, Fast Writes works fine one some machines. I had it on for my 9800np on both an IC7 (intel 875P chipset) and A7N8X-X (Nforce2) and had zero problems.

Hm. That is odd. Here are my specs:

Athlon 1900+
Shuttle AK32A mobo (VIA KT266)
Radeon 9800np
120GB Western Digital Hard Drive with 8 MB of cache
400W Antec PSU
Lite-On 52x32x52

It kindo of bothers me that it runs like hell with fast writes on, but performance is rather kick-ass anyway, so it's not too bad.

 

[BFG10K]

FastWrites speed up rendering speed because they allow the CPU to communicate with the GPU without touching the main memory.

They are fully supported by both ATi and nVidia so if they don't work then it's usually a system problem/configuration issue. Generally non-Intel motherboards tend to form the bulk of the ones that have issues when it's enabled.

 

[dguy6789]

Thats funny, my 9600 pro would crash and not run C&C generals unless i enables fast rights. So it appears that if it does not work right, you have a configuration problem, or your system is not stable.

 

[JBT]

With my old MSI KT3 Ultra 2 Fast writes would kill my machine. With my new A7N8X DLX it works perfectly with them on never tried with it disabled on the new board.

 

[MisterRaven]

I had no problems with fast writes with my old GeForce 4 Ti 4200. . . Oh well, I'll be replacing the motherboard soon anyway.