Need help new ram for system cas4 or 5?

[XeRo_Dark]

Well first off its been around 3.5 years since my last upgrade so buying a new cpu ram mo-bo and vid card. Obviously going to wait it out for video card since its rumored that anytime from now till the 15th-ish for nVidia to release their new 45nm cards (crosses fingers for next week).
aaanyway im at somewhat of a crossroad between getting,

http://www.newegg.com/Product/Product.aspx?Item=N82E16820145034
CORSAIR XMS2 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory, cas 4-4-4-12
or should i save myself initial 22 dollars + ship before rebate with,
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145590
CORSAIR XMS2 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory, cas 5-5-5-12

I guess what im really asking is. Is there really any noticeable difference of 5-5-5-12 and 4-4-4-12, in gaming applications as well as general usage? or would i be better off saving the extra 22 bucks, which could go for something else and getting the cas-5. any suggestions or recommendations would be a great help
thanks,
~me~

 

[BillParrish]

I doubt you will ever feel it. HOWEVER, the cas 4 stuff gives you room to loosen the timings for high FSB overclocks. Most of the Intel cpus have a mulit of 8 or higher so at the memory stock 400MHz FSB x 2, you could get to 3.2GHz cpu speed with an 8 multiplier or 3.6GHz cpu speed with 400x9 and your memory would not even be overclocked.

However if you had (like me) say an E6300 running at a max cpu multiplier of 7 at 470+FSB (940MHz memory speed, these boards do not have memory dividers, only multipliers) the ability to loosen the timings is critical. I have 2 sets of that corsair CAS 4 memory, one from last year and one just bought 3 weeks ago. Both pairs will go to 950MHz memory speed at 5 4 4 12 timings on my gigabyte P965 DQ6 ver 1.

The Cas 5 stuff sould be good to 425MHz (ish) more than that would likely require using Cas 6 timings and you might could tell the difference there, its pretty slow.

Not OCing, save the 22 bucks.
OCing, look at your CPU max multiplier, your reasonable target OC based on the heatsink and board you intend to use and decide. If a gamer and the $22 would let you go for a better video card, or even a better heatsink, the Cas 5 stuff would be the way to go. All that said if you can get the other stuff you want and the wife would spend the $22 on curtains, go with Cas 4.