New Memory Highs: Corsair and OCZ Introduce DDR550

Test Results: Corsair XMS4400 & OCZ PC4400

To test overclocked stability, we used the very demanding Gun Metal 2 - Benchmark 2, which pushes systems with its DX9 routines. To be considered stable for test purposes, Gun Metal, our Quake3 benchmark, UT2003 Demo, Super PI, Halo, and Comanche 4 had to complete without incident. Any of these, and in particular Super PI and Gun Metal, will crash a less-than stable memory configuration.

Corsair XMS4400v1.1 TwinX - 2 x 512Mb Double-Bank
Speed	Memory Timings & Voltage	Quake3 fps	Sandra UNBuffered	Sandra Standard Buffered	Super PI 2M places (time in sec)
400DDR 800FSB	2-3-3-7 2.55V	318.1	INT 2663 FLT 2639	INT 4442 FLT 4445	133
500DDR 1000FSB	2.5-3-4-7 2.65V	390.2	INT 3147 FLT 3228	INT 5549 FLT 5520	108
533DDR 1066FSB	2.5-4-4-7 2.75V	411.9	INT 3345 FLT 3362	INT 5842 FLT 5819	102
550DDR 1100FSB	3-3-4-8 2.75V	422.9	INT 3415 FLT 3529	INT 6054 FLT 6008	98
560DDR 1120FSB	3-3-4-8 2.75V	436.8	INT 3606 FLT 3538	INT 6124 FLT 6101	95

Corsair XMS4400 did not perform any better or reach higher overclocks when using 2.85V for the memory. In fact, performance was often worse or we got a no-boot condition when 2.85V was selected. 2.75V allowed us to get all we could from Corsair's DDR550.

OCZ PC4400 Dual-Channel Kit - 2 x 512Mb Double-Bank
Speed	Memory Timings & Voltage	Quake3 fps	Sandra UNBuffered	Sandra Standard Buffered	Super PI 2M places (time in sec)
400DDR 800FSB	2-3-3-7 2.55V	319.3	INT 2686 FLT 2653	INT 4455 FLT 4422	133
500DDR 1000FSB	2.5-3-4-7 2.65V	387.7	INT 3146 FLT 3246	INT 5516 FLT 5470	108
533DDR 1066FSB	3-3-4-7 2.75V	412.2	INT 3416 FLT 3450	INT 5846 FLT 5888	102
550DDR 1100FSB	3-3-4-8 2.75V	421.9	INT 3446 FLT 3518	INT 6040 FLT 6003	98
571DDR 1142FSB	3-3-4-8 2.75V	438.5	INT 3752 FLT 3642	INT 6231 FLT 6237	94

OCZ PC4400 reached approximately the same overclock at 2.75V that we found with Corsair's DDR550. That is, both reached about DDR560 at 2.75V. The OCZ did not have a problem with 2.85V, however, and continued on to 571DDR. Frankly, neither of these results with DDR550 shows much headroom. 560 and 571 represent just 1.8% to 3.8% over the DDR550 specification. This is much less "reserve" than we normally see with Premium memory.