RAM Advice

http://www.newegg.com/Product/Produ...mpareItemList=N82E16820231116,N82E16820231130

I will be buying one of these 2 sets of RAM to upgrade the RAM in my laptop. Why is one more expensive then the other? The only difference I see is the CAS Latency. What is the difference between a CL of 5 and a CL of 4? I know a lower CL is better, but what is the difference between 4 and 5?

 

If i rem. the CAS Latency is the time in nano seconds it takes the RAM to locate a specific address or something like that... So in general, as you said, the lower the better...

I would personally choose 4 over 5, but it depends what you will be doing since you might not really notice the difference ...

 

I am not going to explain other than simple terms because that is all I can do. If it takes 4 cycles to get to the needed info vs 5 cycles the diff is, CL5 is 25% more than CL4. So you have 667 cycles/s if that was all that mattered (not that simple but best I can do) the CL5 would be 25% slower retrieving info.

To give an example 667Mhz is 25% faster than 533Mhz but 677Mhz CL5 and 533Mhz CL4 have about the same actual bandwidth because the faster speed is offset by the delay in getting the requested info. Both you are looking at are good but the CL4 will be about 20% faster (actual bandwidth), I think it is worth it.

 

I'm a hardcore user, so I'll probably go with 4, but I wanted to be sure that it'd be worth the extra cash.

 

The core 2 duo processors aren't memory latency dependent, so the difference between CL4 and CL5 won't be much,maybe not even noticeable.

 

Either way, I want to match the FSB of the processor with the clock speed of the RAM. (both at 667MHz)

Thanks for the help guys!

 

In the case of the new Santa Rosa chipsets, the FSB of the memory has a max of 667MHz, while the FSB of the CPU is 800MHz. If you purchase 800MHz RAM, it will be a waste of money.

 

biohzrd, amen