Clock Spectrum & Aperture Size ?

[chrispy]

Folks,

In the BIOS, there is a setting for Clock Spread Spectrum and AGP Aperture Size.

What are those settings for and how can a wrong setting affect the system ?

Appreciate any enlightenment.

-chrispy

[Mark F]

Clock Spread Spectrum is for testing perposes and should be turn OFF. Generaly a AGP Aperture Size of 1/2 total RAM should work fine. There have been sugestions for setting it to total RAM, but I beleave this is for specific problems/combonnations/etc .

Mark F.

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OH NO, my retractable cup holder swallowed a CD

[gbm]

1. AFAIK, spread spectrum setting causes slight fluctuation of clock period, which makes the system produce less electromagnetic noise and probably slows it down by a fraction of percent.

2. According to common sense, AGP aperture size should be set to 1/2 memory size. According to many experiences, the good setting seems to be equal to main memory size - this in fact yields the REAL aperture size equal to 1/2 mem size.
If someone REALLY knows how this setting works, please enlighten us...

[This message has been edited by gbm (edited 08 November 1999).]

[Agent31]

OK, forgetting common sense for a second, setting the AGP appature to 1/2 of your system memory is not a guarentee for anything, it is however a very good place to start. I have had varying amounts of memory in my system, ranging from 64MB all the way up to 384MB for a very brief period, now, I'm not saying that this is the case for all people, but I cannot get any D3D games to run on my G200 with the AGP appature set to anything other than 64MB.

Now, that said, 64MB is my recommended starting point to anyone who is unsure of what to set. People may argue the technicalities, and I'm more than happy to join in, but 64MB is my recommendation. Let us know how you get on!

Dave

[chrispy]

Thanks for all your enlightenment...my system is running at 128MB and my aperture size is also set to 128MB and I am running fine. I have actually tried setting it to 64MB at one stage and it didn't felt any different.

I am leaving it at 128MB since it is not causing any major problems.

-chrispy