Hyperx hx426c15fbk28 is a kit of two 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 total kit capacity is 8gb 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 tr