The current Intel nehalem and sandy bridge cpu's have an excellent integrated ram controller. It is able to keep the cpu fed with data from any speed ram.
The difference in real application performance or FPS between the fastest and slowest ram is on the order of 1-3%.
Synthetic benchmark differences will be impressive, but are largely irrelevant in the real world.
I see no negative with 16gb. No game will use more than 2-3gb, but lots of ram will be used by windows to keep code in ram, ready for instant launch.
Ram is sold in kits for a reason.
Ram from the same vendor and part number can be made up of differing manufacturing components over time.
Some motherboards can be very sensitive to this.
Although, I think the problem has lessened with the newer Intel chipsets. Still,
it is safer to get what you need in one kit.
It often turns out that a single kit will be cheaper too.
8gb sticks have come down in price, but are still a bit more expensive per gb than 4gb sticks.
The advantage of 16gb using 2 x 8gb is that the voltage to run two sticks is easier to manage than 4. When oc'ing, this may be an issue, depending on the motherboard.
2 x 8gb also gives you an option to go to 32gb.
Ram is relatively cheap, so it does not pay to anguish too much about it.
You want documented ram compatibility. If you should ever have a problem, you want supported ram.
Otherwise, you risk a finger pointing battle between the ram and motherboard support sites, claiming "not my problem".
One place to check is your motherboards web site.
Look for the ram QVL list. It lists all of the ram kits that have been tested with that particular motherboard.
Sometimes the QVL list is not updated after the motherboard is released.
For more current info, go to a ram vendor's web site and access their ram selection configurator.
Enter your motherboard, and you will get a list of compatible ram kits.
While today's motherboards are more tolerant of different ram, it makes sense to buy ram that is known to work and is supported.
i have checked with asrock and the ram from gskill is compatible i was thinking 16gb because i dont ever see me using more than 4-6 so 16 seemed pretty overkill for both future proofing and general use
i agree with recon-uk, its inside a haf x on a z77 asrock with a h100 id perfer to just get the ram thats good and looks good then the ram thats great but looks very very cheap even if it isnt
Obviously everyone is entitled to their opinion. I've always been a Performance > Price > Aesthetics kinda guy. You won't find better performing RAM than the 30nm Samsungs right now. If you want to get the prettiest RAM, this thread is kind of pointless. Just buy what you want instead of fishing for people to agree with what you have already picked out.