Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
What effect will it have being CL11 as opposed to CL9 ??

If any ?!

In round numbers, the access latency will be 22% longer. If the CAS latency is that much longer, all the other timings will follow suit. With i Core CPUs, CL timings are almost as important as clock speed. For instance, there isn't a significant speed gain going from 1333MHz at CL7 to 1600MHz at CL9. There would be a good speed increase going to 1600MHz at CL7, but to do that you need overclockable RAM with a motherboard BIOS that allows access to timings.
 
It doesn't matter what "brand" of RAM you get, as long as it matches crucial/stock RAM specs, and is a reputable brand, you should be fine. I bought a set of Mushkin RAM for my 2012 MBP that matched the Crucial spec-for-spec. Works perfectly and I saved $60.
 
Wow.

Three years ago it'd have been $700... and for only 8GB...

I'd do full diagnostic testing beforehand, but if it passes 2 or 3 loops and the RAM doesn't get too hot... (I had bought 16GB once and where it was seated got HOT and the test failed during the third loop... a few months later I tried again and, after an exchange, got a set that worked... yippie!)

----------

It doesn't matter what "brand" of RAM you get, as long as it matches crucial/stock RAM specs, and is a reputable brand, you should be fine. I bought a set of Mushkin RAM for my 2012 MBP that matched the Crucial spec-for-spec. Works perfectly and I saved $60.

Back when I did custom PC installs, Mushkin was THE brand to get... I'm sure Mushkin is still top-rated, but PCs are going to be less of a hot commodity in time...

What effect will it have being CL11 as opposed to CL9 ??

If any ?!

Depends on what you use it for. Anything requiring lots of frequent accessing to RAM will have a noticeable impact, but you probably won't see it... database processing, virtual machines, etc, might take a hit, but even then I'd put net quantity of RAM over the latency speed without good reason to make such a decision... benchmark tests would tell the full story, but the differences are rarely that important...
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.