Comparing 4 Corsair RAM models

[trey21]

I am looking to build a computer: Intel i7 920, Asus p6t deluxe v2.

Which RAM would work best for durability, speed, multitasking? I have read on these forums Corsair was one of the best, so that's why I'm comparing these that others advised. I just cannot tell the difference between them.

CORSAIR XMS3 Model TR3X6G1600C9 $131
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145222

CORSAIR XMS3 Model TR3X6G1600C8 G $140
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145236

CORSAIR XMS3 Model TR3X6G1600C7 G $155
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145242

CORSAIR DOMINATOR Model TR3X6G1600C8D $215
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145224

They all look the same, but what is the difference between 7-7-7-20, 8-8-8-24 and 9-9-9-24 timing?

Any advice would be helpful and appreciated.
Thanks.

 

[JackNaylorPE]

Lower numbers = faster

http://en.wikipedia.org/wiki/CAS_latency

 

[trey21]

Why is the
CORSAIR DOMINATOR slower (8-8-8-24) but more expensive than the CORSAIR XMS3 (7-7-7-20)?

Are these two good ones to be comparing?

 

[Mongox]

Why? Because it's slower and more expensive. LOL... Often, the slower RAM is an older design than the faster. And don't believe marketing, just because it has a fancier name or heat-spreaders, doesn't mean it's better RAM. Heck, I love Coke and hate Pepsi, but buy Sam's Cola because it tastes like Coke and costs less than half as much.

You seem committed to Corsair RAM, any reason for that? Or were you just trying to reduce your choices to something reasonable?

BTW, your choices all require no more than 1.65V - which is good, must not be higher. 1.5V would be better, usually means better RAM and newer design.

One thing is to consider whether you really need 1600 speed RAM. Here's an article by Tom's to read - might skip to the last page Conclusions.
http://www.tomshardware.com/reviews/memory-scaling-i7,2325.html

The fact is, that when you consider choosing a 3.0 GHz CPU vs a 2.0 GHz CPU, you can figure that the 3.0 one is basically 50% faster than the 2.0. The same is not true for RAM. 1500MHz RAM is NOT 50% faster in operation than 1000MHz RAM. This is because of factors like the Latency, the CL=8 or 8-8-8-24 type numbers. Those numbers represent delays in the processing of info and increase as the speed of the RAM increases. So that there's really no measurable difference between 1600 @ 8 and 1333 @ 7 or 1066 @ 6. This is the short version of this topic and some will argue points of it, but it's valid.

What there is a difference in is when you compare a single speed of RAM with different CLs. So that 1600 @ 8 is indeed faster than 1600 @ 9.

I would normally recommend some good fast timing 1333MHz RAM. Consider that I use RAM rated at 1100 speed, but use it at 800 because the timings are much better at that speed.

In line with that, I'd recommend one of these, by Corsair and G.Skill
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145250
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231230