Intel DDR2 Divider Options

[Apoptosis]

When playing around on the ABIT AA8XE Fatal1ty Motherboard I wanted to try some memory setting and see what the performance would be like. I was running the 3.46GHz 1066FSB Extreme Edition processor on the ABIT board with the lastest Bios version (11).

Since our processor was running at a strap of 1066 the memory divider is set to 1:1 thus giving us 266x2 which would be DDR2 533MHz.

Since memory isn't holding these board back why should we be stuck with 533Mhz memory on this gamers board? By changing the northbridge strap to 800MHz we got more memory dividers to use. The most interesting is the DDR533 divider becase it is set to 3:4. Keeping our FSB the same (266MHz) we just changed the northbridge strap and the memory divider. (although both show DDR2 533 in the bios).

Let's get to some numbers...

Using Corsair DDR2 PC-5400 we used the following settings:
DDR2 533 @ 3-3-3-8 timings
DDR2 720 @ 4-4-4-12 timings

3.46GHz w/1066 strap and 533MHz memory divider (1:1)

Memory Write: 7252 MB/s
Memory Read: 2253 MB/s
Memory Latency: 78.3ns

3.46GHz w/800 strap and 533Mhz memory divider (3:4)

Memory Write: 7856 MB/s
Memory Read: 2665 MB/s
Memory Latency: 70.7ns

As you can see by just simply changing the memory divider and northbridge strap that is found in the BIOS you can raise your increase your memory bandwidth even with looser timings!

[infinitevalence]

i dont know what is about you memory and straps but all i can say is ummmmmm...

[Apoptosis]

Maybe this image i just tossed together will help you understand what I am doing. I am changing the strap to get new memory divider ratios!
Under the 800 strap there is a DDR600 option which is 2:3, but it fails to work on the ABIT AA8XE Fatal1ty board thus far.

[Illuminati]

I noticed the 2:3 memory divider on the ASUS P5GD2 Premium was causing random restarts while booting, too... seems like that is the divider to fix on these 915/925 boards.