PXD38G1866ELK (Viper Xtreme PC3-15000, 1866MHz, Division 2)
ASUS Sabertooth Z77
Intel i5 3570K
Under automatic settings, the motherboard sets the DRAM frequency to 1333 MHz. This seems to be consistent with what ASUS AISuite and CPU-Z thinks the RAM's maximum bandwidth is (AISuite shows 667, CPU-Z shows PC3-10700 (6677 MHz).
If I force the RAM to run at 1866 via Manual or XMP, CPU-Z shows the following:
DRAM Frequency 933.4 MHz
However, both AISuite and CPU-Z both still show maximum bandwidth of 667MHz (PC3-10700). Also, under Manual set to 1866 and XMP, performance is noticeably slower than Automatic at 1333 (1:5, 9-9-9-24-2T) while running the same applications, and occasionally my computer will blue screen. Using different RAM Slots seems to have no impact on the results displayed.
How can I get my memory to perform at its listed specs?