DDR RAM and AGP

[gwilks98]

Two questions:

Can anyone tell me what exactly is this DDR RAM I've been hearing about?

When you hear that a mobo has an AGP divider of 1/2, what does that mean?

Thanks,

Wilks

[Goutham]

I'm not too sure what the AGP divider of 1/2 is, but I do know what DDR RAM is.

DDR is high performance ram that sends data on the rising and falling edge of the clock, effectively doubling the data rate. So if you have 100 MHz clock, the DDR would be 200 MHz. I believe that AMD is releasing a board to support DDR RAM next month or so.

[Dave_7]

The AGP bus' native frequency is 66MHz. The motherboard uses an electronic divider to make the AGP bus run at a fraction of the Front Side Bus speed. If the FSB is 100MHz, then the AGP divider will be set at 2/3. If the FSB is 133MHz, then the AGP divider will be set at 1/2. Only recently have boards come out with (real) support for 133MHz FSB. Support.. meaning, among other things, a 1/2 AGP divider. If the FSB is 66MHz, then the divider is set to 1/1.

It's important in overclocking because if you want to run a P3 700 on a 133MHz bus so it will magically become a 933 chip, then you'll want an AGP divider of 1/2 so that you can use your AGP video card. If your board only supports a 1/3 divider, then you will be running your AGP bus at nearly 90MHz... which is a lot. Too much for many video cards to handle.



Off to work,



Dave.

[sbp]

"When you hear that a mobo has an AGP divider of 1/2, what does that mean?" This means the AGP bus which your AGP videocard uses runs at half the speed of the system bus speed. 133Mhz system bus speed means 66Mhz AGP bus speed.

(blatant cut and paste since search engine apparently doesn't work}

DDR is Double Data Rate ram that transfers information on the rising and falling edges of a clock cycle. Basically almost twice the data is being transferred in a clock cycle compared to SDRAM.

Some videocards like the GeForce GTS use this type of ram: http://www.karbosguide.com/module2e.htm#RDRAM

Sharkyextreme preview of AMD DDR chipset: http://www.sharkyextreme.com/hardwar.../tyan_760_ddr/

Tomshardware preview of Micron's DDR chipset. http://www6.tomshardware.com/mainboard/99q4/991216/

Pictures of DDR ram: http://www6.tomshardware.com/busines...13/mp3-02.html

Oh My here's a new link for everyone to look at about DDR ram!

Inquest article about VIA’s Apollo Pro266 DDR Chip Set for Pentium III's: http://www.inqst.com/articles/p3ddr.htm