Kingston KHX8500D2K2/4GR 4GB 2GB 256M x 64-Bit x 2 PC2-8500 CL5 240-Pin DIMM Kit Power supply : Vdd: 1.8V  0.1V, Vddq: 1.8V  0.1V, Double-data-rate architecture; two data transfers per clock cycle Bidirectional data strobe(DQS), Differential clock inputs(CK and CK), DLL aligns DQ and DQS transition with CK transition Programmable Read latency 5 (clock), Burst Length: 4, 8 (Interleave/nibble sequential), Programmable Burst type (sequential and interleave) Timing Reference: 5-5-5-15 at +2.3V, Edge aligned data output, center aligned data input , Auto and Self refresh, 7.8us refresh interval (8K/64ms refresh) Serial presence detect with EEPROM, High Performance Heat Spreader, PCB : Height 1.180-Inch (30.00mm), double sided component