can anyone please explain ratios to me?

[CyberGhost]

is this example:

P4 2.4C 3.6GHz FSB 300MHz Abit IS7 Kingston HyperX 3500 2x256Mb 2-5-2-2 (5:4 ratio)

what is this 2-5-2-2 (5:4 ratio) thing?

what's it good for? and how calc it?

[elmers]

Memory latency?

[duramax]

for the best information regarding cpu ratios and the like try:

www.overclockers.com

Very informative, but kinda difficult to navigate if your a newbie.

Good luck!

DuraMax

[joker_927]

5:4 means that for every 5 mhz his CPU FSB is, his memory is only 4 mhz. I think

Intel's FSB is wierd. That states 300mhz FSB. That would mean a full FSB of 1200mhz! Weird.

My CPU:Memory ratio is 100% (1:1). I have my FSB set to 200mhz, and my memory is running at 200mhz also.

[davidamarkley]

The serires of numbers (2-5-2-2) refers to the memory timing. The lower the better normally.

Here's a breakdown of what I believe the numbers mean:

2-5-2-2

2 = CAS latency
5 = RAS precharge
2 = RAS to CAS delay
2 = RAS active to precharge

These numbers indicate the amount of milliseconds for each operation. Therefore, the lower the numbers, the faster the memory can perform. Also, the lower the numbers the better the overclocking potential of that stick of memory.

HTH,

David

[John Prophet]

uhh. I think it goes like this.

Thats the divider ratio between fsb and ram speed.

In that example the fsb is 300 mhz so with a 5:4 ratio the RAM speed is 240mhz.

The deal is that when you overclock your fsb you are also overclocking your RAM....so they use the dividers to allow the fsb to be increased but to divide it back down for the ram cuz the ram is being the speed limitation.

1:1 obviously means the fsb and ram are running the same speed.

5:4 means the ram is running 4/5ths as fast as the cpu

3:2 means the ram is running at 2/3rds the cpu speed.


Here is a paragraph from an article
" There is also, usually, a CPU Frequency to RAM Frequency ratio available. Common ratios available are, but not limited to, 3:4, 4:3, and 4:5. They are applied in the order in which they appear. For example, if the ratio was set to 4:5 with a CPU Frequency of 133 MHz, the resulting RAM Frequency would be 166 MHz. (133 multiplied by 5, all divided by 4). It is advised you keep the CPU Frequency: Ram Frequency ratio to a 1:1 ratio while you are in the testing phase. They can be adjusted later just as easily once you know the limits of your machine. Next stepping up to the plate is the CPU. "

The article was here http://www.extensiontech.net/article...guidept1.shtml

and here is a link where some peeps discuss it also http://forums.extremeoverclocking.co...d/t-63354.html

A motherboard article where they discuss the various divider ratios available on the particular motherboard http://www.neoseeker.com/Articles/Ha...i648max/2.html

JP

[tgxiii]

You can learn more about memory latency here:

http://www.corsairmemory.com/memory_...707/index.html

I posted this a while ago in this thread:

http://www.techimo.com/forum/showthr...corsair+memory

[Gait_Keeper]

Very great info here!!!!

I've learned more from this thread than 6 months of college

ok, ok I never went to college( enrolled ), unless there was a party there ( still didn't enroll, just partied )

[CyberGhost]

Thanks you for the lesson guys!, that question was bugging me sometime