Memory Specs And FBS specs.

Can someone pleas help me whith the Memory Spcecs and what they mean And the FBS and what they mean.

Ok i am seaning Memory specs or memory speed like the CAS and other stuff like 2-2-2-2-0-2 What does all of thoes numbers mean. and what does 3:4 and 5:6 mean?

Now when it comes to FBS and memory I only know What things mean with SDRAM you konw where the FBS of the Motherboard is eather 66/100/133 and The motherboard and CUP and memory runes at all the same speed.

But when it comes to DDR SDRAM and RDRAM I am getting lost and i need some explaining. Like Lets say you mother board is running as 133MHZ And you have DDR RAM how can you Memory run at 266 if you FBS is REally 133.

So if some one can explaing how the Memory speed and bandwith works and how it is effected by the FBS for DDRAM and RDRAm i would be thank full.

I am realy REally lost

Thank you all for you help.


I am confused

The FSB is you main bus which drives everything. Your CPU gets the fsb clock and it gets multiplied by the cpu multiplier to give you it's final speed, ie 100Mhz x 16 (P4-1.6) = 1.6Ghz. Your memory gets the same fsb clock, but DDR clocks on the leading edge and the trailing edge of a pulse so it effectively has a multiplier of 2, and the new quad data rate ram will be 4x. So at 133fsb with DDR it's speed is 133x2=266. As you can see, as you change the fsb so the cpu and memory clock speeds change also, so does the PCI clock and the AGP clock. The FSB is the master clock.

The ratio's you are seeing were developed because the CPU's multiplier is locked and the only way to speed it up is to increase the FSB, but that can take other components out of spec to the point that they won't function, or will function erratically. The ratio is a multiplier/divider combination so that if you are at 100 or 133 fsb you can run your memory at it's specified speed. You can also use it to run your memory faster. In the bios you will usually see the actual memory bus speed in light blue based on the fsb and the clock ratio, it sometimes also has a x2 after it. So if you have pc2100 (DDR266) memory on a 100Mhz fsb then the ratio should be set to 4:3 (ie 100 x 4/3 = 133 x 2 = 266) which gives you your memory speed.

Okay so far ????

The numbers you see such as 2-2-2 and 2.6-3-3 refer to the internal timings of the memory and have to do with latency and address strobing (clocking). Older bios adjustments were limited but the newer bios's really allow you to tweak a memories performance - this takes time and patience and a benchmarking tool such as SiSoft Sandra. Quick settings can usually be found in the new bios's by setting the timings to Normal, Fast and Turbo.
The setting that makes the most difference is the CAS (column address strobe) and if you can go from CAS3 to CAS2 quite an improvement in memory bandwidth can be realized - it will take aproximately and increase in fsb of 15~20 mhz on SDR to be equaly to a change in CAS from 3 to 2. Depending on your motherboards bios you can usually get onto the Advanced Memory Timings and see all those timings and even adjust them - but be aware that if you push it too far you will probably have to clear your cmos to get your computer to boot back up.

SiSoft Sandra will give you the specs and settings of your memory in it's sytem info. There are other explanations on the web that go into far more detail than I have, Adrian Rojak's site has an excellent in-depth explanation along with many other articles which can be found here :- http://www.rojakpot.com/

Hope that helps and wasn't too boring.

I love you Limey

I was exactly wondering the same thing, but hadn't done anything about it (i.e. search/ask/whatever)


Thanks!

Thank you alot man that helped. I am slow learnder and simple things sometime do click. I am trying to studdy to pass my A+Certification Test and on the side i am trying to learn how FSB and overcloking works. Hehe.

No you info was not boring. I will check out the Website you gave me.

Once agin Thank you.

Thank you both for your praise, I'm only too glad to be of help, and I'd like to add my "Welcome to Overclockers" to any other weclomes you have already received.

Thank you once agin.