I'm new at AMD o/cing. I'm trying to figure out what is what, so far here's what I've learned:

HTT is 200 (default for AMD64 processors)
HT Multiplier or LDT Multiplier is 5 (default for AMD64 processors)

HTT x HT = FSB
200mhz x 5 = 1000mhz (this should never exceed 1000)

CPU Multiplier is 9 default for Winchester
CPU Multiplier x HTT = CPU Clock
9 x 200mhz = 1800mhz (default for AMD64 3000+)

I know that the HTT, HT, CPU Multiplier can be upped. However, I do not understand the memory divider and how it relates mathematically to overclocking. Can someone please explain this and give an example?

Thanks.

So if I'm using a DDR400 ram, which divider should I use? I intend to o/c my CPU up to 2.4ghz (currently at 1.8ghz).

Here's my current rig:
AMD64 3000+ (winchester)
4x256MB HyperX DDR400
Asus A8N-SLI 939pin

UPDATE:
I found out this:
CPU Clock / Memory Divider = Memory Clock
1800 / 9 = 200 (default for DDR400)

Now if I would to up my CPU to 2400mhz,
I take the intended CPU Clock and divide it by the CPU Multiplier of 9 (I will assume that this multiplier is locked),
2400mhz / 9 = 266mhz which is the HTT

With HTT at 266mhz, I would need to reduce my HT Multiplier because at the default of 5, it would exceed the 1000mhz limit (266 x 5 = 1330mhz) and will be unstable.

So I'll reduce the HT Multiplier to 3,
266mhz x 3 = 798mhz (well below the limit)

Now, for the memory divider, I know I should also reduce it because now its currently at 1:1 (HTT:Memory Clock) ratio. Because if I don't,
266:266 would make my memory operate at 266mhz which is too much for a DDR400 RAM (should be 200mhz or below).

Theoritically, I should divide the new CPU Clock by 12 to get this,
2400mhz / 12 = 200mhz (which is the memory clock of my DDR400 i.e. would be stable).

From your example above, I cannot figure out how to get this 12. Anyone?

This post has been edited by ZipD: Feb 27 2006, 03:50 PM

Thanks for the proggie. It's very useful. But since I'm mental, I went to look for more info on the ratios and although I didn't find the formula either (maybe it's very complicated), I found a very useful chart by someone named Oskar from DFI forums (I think most DFI o/cers would know him) here in Extreme Overclocking 's guide (it's right at the end).

From there, I can deduce that in order to achieve 2400mhz on my Winchester, I will need to use the 3:4 ratio. Now this is going to get confusing...

The 3:4 ratio will set the DDR memory clock to 150mhz. If you refer to the chart, at the CPU multiplier of 9 row, I should get what I'm looking for, a 9:12 ratio.

So 266mhz of HTT (base clock) x 3 / 4 = 199.5 i.e. approximately 200mhz of my DDR400.

BUT... I think my mobo doesn't support this particular setting of 150 (3:4) DRAM frequency

So back to the drawing board

I'm using 4 x 256MB Kingston HyperX PC3200 sticks. Here're the timings:



This post has been edited by ZipD: Feb 28 2006, 10:03 AM