Asrock 990FX Extreme 9 Memory. Totally Confused.

memory controller is for up to 1866 on thenm chips but this can vary from chip to chip your chip may do that easy and more but it may not amd is not known for a strong memory controllers. most time you should be safe with the 1866

whats on the boards tested memory list under what you want ??? something like these should work

http://www.newegg.com/Product/Product.aspx?Item=N82E16820231528&SortField=0&SummaryType=0&PageSize=10&SelectedRating=-1&VideoOnlyMark=False&IsFeedbackTab=true#scrollFullInfo

ok- I don't blame ya -- its all a gamble with any brand memory board and chip got to work hand in hand and if you get something that's finicky you got issues regardless the brand but you can only do what you feel is best for you

2x8GB - look to the GSkill Snipers or Ripjaws X in 1866/9 or 2133/9, both should be fine

I had memory that did not do so well on one board but worked excellent on another was it the chip was it the board both were 990fx anus and gigabyte [nothing worked well on my last 2 asus boards to be honest ]

Anus! LOL...had to say it. Now that is a typo..........

I don't own the AsRock Extreme9 but the Extreme6. Buying memory for these AsRock boards is very tricky due to the AMD memory controler and AsRock bugged BIOS.

If you're going to have a memory configuration where you use all memory banks, you must take the following into consideration:

http://support.amd.com/PublishingImages/Support/CPU-DDR3/memory-table.png

1.When installing modules of memory of differing speed grades or brand, the memory will always run at the speed of the slowest module installed.
2. The amount of populated memory slots can affect the achievable final memory running speed.
3. Memory design in Single or Dual rank can effect memory speed. Dual rank memory will run slower than a Single Rank memory of equal quality,
4. AsRock BIOS is bugged, If you have memory a SPD profiler with speed higher than maximum memory speed supported by the CPU controller, the AsRock BIOS is going to set that speed. You computer might not boot.

In my personal case, I have 32GB of RAM of 1866Mhz memory - all slot are populated. My memory RAM is Dual Rank which means the controller doesn't officially support speeds higher than 1333MHz. The Asrock 1.40 bios (and all before this one) sets the ram speed to what the SPD tells, which is 1866, It's an unwanted overclock of ~40%.As you can image, the computer doesn't do anything... not even beep.

The Asrock overclock crash guard that supposedly sets a "good" bootable profiles picks the same configuration which means that the computer isn't bootable - or, in layman terms, the guard feature doesn't work.

I've contact Asrock tech support, which claimed this is AMD fault (it's constraint, not a error) and when they acknowledge the problems (after several emails), provided a "custom" build just for me, supposedly compatible with my configuration - but who knows what was in that bios config.It seems that Asrock engineers can't figure out an algorith that fits all basic rules - set the most compatible configuration. When asked to publicly release the fix they refused.

Long story short, my advise is to avoid Asrock if you find similar product from another brand or if you're sure you won't need the tech support.