should be ok, but on that page you linked, there is the memory QVL, that would be step 1 to see if maybe there has been 8gb per stick tested. Not that it matters to me overall, but why 16gb total memory, are you even using 8gb? why not 4x4gb will still give you total of 16gb, and also, again not sure what cpu you are using etc, but why not go for the ddr3 1600 speed if it will support it, not much price difference, and from a performance standpoint, 1600 speed is worth it(I am assuming you do "work" with it and not just gaming)
It is running XenServer, with two CentOS vm's one, solely for teamspeak, the other Minecraft. I will need all 16 gigs of ram
The cpu is: AMD Athlon 2 x4 640.
The spec's didn't say anything about 1600, although it does say 1866 Overclocked.
Well, if it says 1866 overclocked, then the likely hood is that 1600 @ 16gb will work just fine as well.
It does help to have the new C3 stepping as they do not seem to mind it as much, but offically, AM3 cpu like that Athlon II x4 640 and my Phenom II x4 955BE support ddr3 1333 as default "max" speed, to use ddr3 1600 or higher it is considered "overclocking" usually if its not playing nice, it just takes a couple minutes to fine tune the cpu/nb-memory controller a bit faster so it can "talk" to the 1600 or better speed memory without issue.
But it does help, especially for things like VM running servers etc, they usually need as fast access to the cpu/memory as possible, less on raw speed, and having higher clocked memory, and a higher clocked memory controller will help alot.
I wouldn`t go with that one you pointed out in second link, its timing is very high which is not good for performance reasons, not to mention, looks like a very large heatspreader.
You want something that uses 9,9,924 or lower timing e.g first number is CL lower the better. You also want to get something with as low voltage as possible, which for now is 1.35v or 1.5v, it helps for stability when overclocking and usually has a better chance to hit a higher speed, not always mind you.
only an example in the link above to show the speed/pricing/voltage/heatspreader height.
The other thing to take note of, just because its not in the QVL does not mean it will not work, its just memory they have tested to comply and list it as such is all, not to mention, they usually stop updating the QVL a few months after the boards release.
You can always email one of the memory makers as most of them are quite helpfull, I use Gskill cause in my experience, they and corsair are very very helpfull.
I would ask them directly if they recomend using or know if the 2x8 or 4x4 sets will work as they should. Its much easier to drive 2 sticks then 4 sticks, but there have been known issues with driving alot of memory all at once on certain motherboards.
There is also the side, that you may need to declock the memory as it may not run at its full speed e.g 16gb total may need to run at max 1333 speed. I do not know. I use 8gb and I am happy, I can run mine at 1866 as well, which for my chip, is not usual.
But yeh 4x4 is more likely to work then 2x8 sticks, but, the cpu you are using may have trouble driving 16gb to begin with, considering, it probably was not designed with what you have in mind
I would send email to Gskill, Corsair, Geil, Patriot more then likely they can give you a much straighter answer then I can lol