AGP Aperture Size Question

[StormbringerGT]

Hello, I am troubleshooting some problems on my PC. When going through my bios I noticed that the AGP aperture size was set to 64mb. I have a Radeon 9800 XT which has 256mb. My question is. Does this matter? I should I set my AGP Aperture to 256mb? There is an option to. If anyone knows more about this than me please help! Thanks!

David

[StormbringerGT]

Whoops one more newbie question. My SDRAM Frequency is defaulted at 266MHz. But it can go up to 400Mhz. Should I? I mean my Actual DDR is 400MHz. Does my SDRAM and my actual DDR Ram have anything in common? And what is SDRAM? Sorry I got to learn somewhere and sometimes! Thanks!

David

[Killer_Typo]

No one actually really knows what the AGP aperture size is for. My dad used to write device drivers for video/sound card and says that most all drivers are written to ignore it, and it doesnt matter what size you set it to. as to your sdram frequency. i dont know because i dont often mess with that sort of thing. but im guessing its set to be as fast as the comp can handle???

[StormbringerGT]

Okay that helps. So I guess I am cool with the AGP size. However I just read something. The bios states, SDRAM Frequency is defaulted 266, but can go up to 400. However I do not have SDRAM, I have DDR, which actually is 400mhz. I am a little confused by this...

[Catweazle]

What processor do you have? You should have your RAM set to operate at the speed which will have it synchronised with your front side bus, to ensure best performance.

And with modern display cards, AGP aperture size does not matter, because the cards have no need to access system RAM for calculating textures etc. anyway. Quite a few recent motherboards don't even have the setting anymore.

[StormbringerGT]

Thanks Catweazle. I have an intel D865perl Motherboard and an intel Pentium 4 2.6 Hyper threading processor. Well my front side bus is 800Mhz. My bios defaults my SDRAM at 266 Mhz. However it can go as high as 400Mhz.

[Catweazle]

Unfortunately Intel don't seem to see fit to make the motherboard manual available for download, so I can't give specific instructions, but if your front side bus speed is 800MHz, and BIOS setup allows you to, then you should manually set that RAM to operate at 400MHz. It'll be synchronised and more efficient that way.

[StormbringerGT]

Thanks I'll take your advice, I am not sure what harm it can do. I always thought defaults were just safe bests. I do not why it would default the SDRAM so low. Thanks!

[Catweazle]

It'll have something to do with the default settings for BIOS on that motherboard, or if they've been changed, it'll be the result of the changes made. As I said earlier, without access to the motherboard manual, I've no way of telling what the default settings are supposed to be for it.

By the way, just to clear up any confusion about SDRAM and DDR RAM you might have, here's an explanation:

SDRAM stands for Synchronous Dynamic Random Access Memory and is the most common form of memory module used for personal computers. It comes in two main varieties. What we know as SDRAM can operate at speeds of up to 133MHz, can synchronise itself with the processors front side bus timing, and is packaged in 168 pin modules.

As processor speeds increased, standard SDRAM modules became a limitation on system performance, and a newer standard of packaging was developed which allows for higher speeds of operation. DDR SDRAM stands for Double Data Rate Synchronous Dynamic Random Access Memory, is packaged in 184 pin modules and has the capability of processing two instructions per clock cycle.

But at its heart, DDR is still SDRAM, which is why you see mention of SDRAM in the BIOS POST screens, and in BIOS Setup. The fact that it is processing two bits of information per clock cycle is why, in many BIOS Setup menus, you need to set the value to half of what you actually want to achieve.

[StormbringerGT]

Thanks for clearing that up! Now if only I could fix my other problem in my other post....Thanks for your help catweazle and killer_typo!