Hyperx hx426c15fb4 is a 512m x 64 bit 4gb ddr4 2666 cl15 sdram synchronous dram 1rx8 memory module based on eight 512m x 8 bit fbga components per module each module kit supports intelreg extreme memory profiles intelreg xmp 20 each module has been tested to run at ddr4 2666 at a low latency timing of 15 17 17 at 12v specifications clidd 15 cycles row cycle time trcmin 45nsmin refresh to activerefresh command time trfcmin 260nsmin row active time trasmin