Patriot Viper Blackout PC4-32000 4000Mhz 16GB (2 x 8GB Samsung Bdie), Selling Due To Upgrade, Does Tight timings, But XMP/DOCP Most Likely Not  Possible If On AMD  AS rare For Memory Controller On Cpu To Support Past 3800mhz, and so manual timings and speed are needed (Had Ran at 3800mhz cl16 for the past year), SO DON'T BID IF ON AMD IF YOU WANT TO GET THESE TO WORK WITHOUT TINKERING WITH TIMINGS.