With 890GX motherboards we are seeing some support for 2000MHz but unfortunately not all can reach that height.  For instance the ASUS M4A89GTD USB3 that OCC used as the base for testing the 2x2GB Mushkin Ridgeback 996902 PC3 16000 is limited to 1800MHz.  In theory, by reducing the total speed of RAM, you should be able to tighten the timings from their default of 7-10-8-27, though as it turns out that was a little optimistic.  The final timings for their testing were 8-8-8-24 so perhaps this kit is not the best choice for those looking to underclock and tighten timings on an AMD board.

“Even after reducing the memory bandwidth by 200MHz for the review, the Mushkin Ridgeback kit managed to perform at a very impressive level. This really showed the additional performance gains by not only higher bandwidth, but also tighter timings. At 1800MHz, this set was still able to use timings of 8-8-8-24 with a command rate of 1T, and did so within the 1.65V requirement.”

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