A64 RAM Frequency Calculator (A64 MemFreq v1.1)

Alot of people probably don't know that A64 RAM dividers aren't clear cut on the calculation of the actual RAM speed.
For insance:

My old Opty 165 system ran at 334HTT x 9 (multi) for 3006Mhz. The RAM divider was set at 166 (5/6). This made for an actual RAM speed of 273Mhz (not 278 as you would logically calculate)
Here is how you figure that out:

Divisor = CPU Clock Speed / (RAM Divider * HTT)
10.8 = 3006Mhz / ( 5/6 * 334Mhz)

Then round the Divisor to the next highest whole number. (not using standard decimal rounding, if it is 9.01 you still round to 10)

So for my example, the Whole number divisor would be 11

Then:

Actual RAM speed = CPU Clock Speed / Whole numbered divisor
273.27Mhz = 3006Mhz / 11



So as you can see, it can be a pain to figure these things out when you are overclocking. I was trying to remember the speed at which my memory was running back then, but I had forgotten how to calculate these dividers so I searched for a calculator....and I found this calculator. It makes things real easy. So I hope this helps someone:

View attachment A64 MemFreq v1.1.zip (10.8 KB)

I have always used these charts
(been in my bookmarks for at least a year)

http://oskarwu.myweb.hinet.net/A64D1.jpg
http://oskarwu.myweb.hinet.net/A64Divider.jpg

Those work, but I find them a little confusing

I first used this:

http://www.deep-powder.net/OC_Guide/advanced/Mechanics/nForce3/Advanced_Overclocking_steps.htm


It's a part of this overclocking guide:
http://www.deep-powder.net/OC_Guide/Mem_Mobo_CPU_Overclocking_Guide.htm

I think to access that page a linked first, you have to click "Advanced version" in the top left....then goto Overclocking Mechanics > 64-bit > Advanced Overclock

Here's the chart from that page:

Yah man.. you on DDR2 now right? And AFAIK the only mobo company that used 1/1 5/6 etc type mentions of ram dividers was DFI. All my other boards (MSI,ASUS, ABIT,JETWAY,AsRock and AOpen) show speed timers (100,133,266,333,400) not dividers to show your speed... so oskar Wus charts work well.. Also not 100% positive... but isnt oskar wu the DFI/abit guy? Just my 2 cents. I only ever remmeber that 10x240 with mem at 333 is 200MHz mem speed that 6/5 i guess....

I've only upgraded to a 939 system in the last month, so this kind of info is invaluable to me. Only yesterday I was trying to figure out why my RAM was running at 204 when calculated was 217

Thanks so much. I wont bother with the program, I'll just remember the formula

Neur0mancer said:

Yah man.. you on DDR2 now right? And AFAIK the only mobo company that used 1/1 5/6 etc type mentions of ram dividers was DFI. All my other boards (MSI,ASUS, ABIT,JETWAY,AsRock and AOpen) show speed timers (100,133,266,333,400) not dividers to show your speed... so oskar Wus charts work well.. Also not 100% positive... but isnt oskar wu the DFI/abit guy? Just my 2 cents. I only ever remmeber that 10x240 with mem at 333 is 200MHz mem speed that 6/5 i guess....

Click to expand...

Well yeah I was on a DFI board...but it works for any type of board. You just use whatever RAM divider is on your board and plug it into the formula.

(100,133,266,333,400)
(1/4,1/3,2/3,5/6,1/1)

And yeah, I beleive Oscar Wu is a DFI designer.