FSB/OC side effects

[nugz45]

So I finally started to OC my Q6600/Thermalright 120 extreme, and have been quite pleased with the results. Just broke 13k on 3dmark06! Woohoo! (I have only got it up to 2.8 so far out of fear of hurting my baby.) My temps are looking good though...33 idle 50 under Prime95 w/ small FFTs, which keeps me optimistic that maybe OC isnt so risky these days.

I have read a lot about it lately, but am still a little lost in when it comes to how the FSB relates to RAM and all that. I know what the FSB actually does and all that, but I'm a little in the dark about how it puts more stress on the RAM.

My question is after I OC'ed to 2.8 from 2.4, my Vista Index for my RAM jumped up by 0.4. My RAM was at 5.4, and when jumping from 2.6 to 2.8 it went up.

So my question is should I also be keeping an eye on my RAM to make sure I dont fry that as well? Are my RAM temps rising? How can I monitor this? Not much of a risk taker, but i decided to give this whole OC thing a try...it looked fun. Keep me safe guys.


tl;dr - Will increasing my FSB too much negatively affect my RAM, possibly before I noctice instability in my CPU stress test?

 

[Nenu]

If you have decent airflow and dont increase the memories voltage beyond manufacturers specs, you shouldnt have a heat problem.
A rough guide to see if its getting hot, hold your finger on a stick.
If you feel the need to remove your finger or its getting near that temp, its too hot.
The faster you clock your memory the more temperature will rise and the more prone to error it will become. ie you can maintain a lower speed at a high temperature that would fail at higher speed.


The FSB is like a base number on which the speeds of the CPU and memory are multiplied up from.

The CPU uses its multiplier x FSB to get it speed.

Memory uses the memory divider x FSB to get its speed.
The divider is often like 1:2, 2:3, 3:2 etc, but sometimes its presented as an actual memory speed like 800, 666.
As the memory is likely to be rated for 200MHz FSB at say DDR2-800, you know that it will run at 4x the FSB speed.

So if you overclock to say a 300FSB, that same memory will run at 1200 unless you change the memory divider to slow it down. In this case you want approximately 2/3 of the speed you need to change the current divider so its about 2/3 of what it was (or set memory speed to near DDR2-533).
As the memory will probably overclock a bit, you might get away with a slightly higher divider (than divider *2/3) or DDR666.
(note: often a divider is represented by say for example 3:2 in the CMOS, not 2:3. If you get it wrong you will probably have to reset the CMOS to recover but there shouldnt be any damage)

Yes overclocking the FSB can stress the motherboard, CPU and Ram.
To find the limit of the motherboard, set the memory and cpu to very slow speeds and test the max FSB that is stable.
That way you know if you are below that FSB, any failure is down to the speed of what you are testing.