Chaintech VNF3-250 Memory Divider Question

monkeymanxe

Junior Member
Aug 27, 2004
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I just picked up an AMD 64 3000+ and a Chaintech VNF3-250. Right now I still have ddr266 ram from my old machine but am looking at getting some new ram. I have the FSB set to 240 and the Ram frequency set at 100mhz right now. I am curoius though, I have seen people posting about using a memory divider(5:6). I havn't been able to find that setting, all I can do is manually set the memory to either run at auto, 100, 133, or 166... also 200 depending on bios revision. I am using the 072904 bios revision. If anybody knows, please let me know.
 

Concillian

Diamond Member
May 26, 2004
3,751
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100 = 1:2
133 = 2:3
166 = 5:6
200 = 1:1

The memory MHz assumes that you are running a 200 MHz FSB speed. At 240 FSB speed you use the divider.

THEN, to find the REAL frequency, you take the clockspeed of the processor and divide by the larges WHOLE number that will have a speed rating BELOW that divisor number.

For example, if you are running 240x9 = 2160 MHz:
1:1 = 2160 / 9 = 240 MHz
5:6 = 200 MHz = 2160 / 11 = 196 MHz actual RAM frequency
2:3 = 160 MHz = 2160 / 14 = 154 MHz actual RAM frequency
1:2 = 120 MHz = 2160 / 18 = 120 MHz actual RAM frequency

This is a side effect of having the memory controller on the processor, the memory controller will work at some ingeter number of cycles of the processor clock speed. This way the memory feeds are always in sync with the processor.

In the case of your processor at 240, all the speeds are exact, as 2400 is evenly divisible by 2, 3, 4, and 6, so your options are exactly 120, 160, 200, and 240.
 

monkeymanxe

Junior Member
Aug 27, 2004
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Actually it's running at 240 x 10. I kinda figured that was the divider, the memory clock. Thanks for the explanation though, that clears up everything. I was looking for something that looked like some kind of ratio or something, that is why I wasn't sure if the memory clock was considdered the divider.
 

Concillian

Diamond Member
May 26, 2004
3,751
8
81
I knew you were at 240x10, but didn't use that as an example, because the 10 multiplier always presents the actual RAM speeds just using the divider. Just wanted to show that the divider isn't the ONLY factor to the RAM speed.

In your case you may want to consider running 9 x 267 FSB:
9x267 = 2403 MHz
1:2 = 133.5 MHz
2403 / 18 = 133.5 MHz

You can run pretty much the same processor speed, but faster RAM speeds.