Can someone help me with calculating speeds and frequencies?

hi guys,

for ages ive wanted to know the formula for the following;

finding out ram freq from the fsb and fsb ratio setting

finding out GPU mem bandwidth from only knowing the freq

if you know this would help - thanks

i found out this one - for ram bandwidth - i think its - ram speed*8/1000 : 1066*8 = 8528 / 1000 - 8.5Gbps

it works for DDR2 and DDR3 - but i cant seem to find out how to calculate GPU mem bandwidth!

The actual ram frequency is pretty easy. It goes like this, you have your baseclock which we will say like for my I5 750 is 133mhz. If I have DDR3 1333 running at that frequency then I have a frequency ratio of 2:10 or a frequency multiplier of 5 giving 665 operating mhz. Now since its Double Data Rate (DDR) you take that 665 and you double that and it gives you 1330 (close enough to 1333) effective mhz on your ram. This is a crude representation but its basically like this;

Baseclock * ratio * 2(DDR) = Effective mhz.

As for the GPU mem bandwidth im not too sure. I believe your on the right track though, some googling would help you alot there.

that doesnt work 4 me im still using fsb!

For you it would be (FSB FREQ x 2)/ratio = MEM Clock Rate

For DDR2-1000 on 1:1 ratio:
(FSB x 2)/ratio = MEM Clock Rate
(500 x 2)/1 = 1000MHz

Using a 3:4 ratio it would be:
(500 x 2)/.75 = 1333 MHz

Check out this post by graysky. It has some formulas in it to figure out what you're asking for. http://www.overclockers.com/forums/showthread.php?t=515316

cheers that works