OCZ VX Revisited: DDR Updates on DFI nForce4

Test Results: OCZ EL PC4000 VX Gold

OCZ EL PC4000 VX Gold (DDR500) - 2x512Mb Double-Bank
CPU Ratio at 2.4GHz	Memory Speed	Memory Timings & Voltage	Quake3 fps	Sandra UNBuffered	Sandra Standard Buffered	Super PI 2M places (time in sec)	Wolfenstein - Radar - Enemy Territory fps
12x200	400DDR (Stock V)	2-3-2-6 2.6V 1T (Stock V)	567.4	INT 2852 FLT 3000	INT 6128 FLT 6082	81	119.2
12x200	400DDR	2-2-2-6 3.0V 1T	572.8	INT 2918 FLT 3070	INT 6154 FLT 6100	80	120.2
11x218	436DDR	2-2-2-6 3.1V 1T	580.2	INT 3075 FLT 3250	INT 6538 FLT 6465	80	121.4
10x240	480DDR	2-2-2-6 3.2V 1T	600.1	INT 3230 FLT 3402	INT 6804 FLT 6726	78	123.5
9x267	533DDR	2-2-2-6 3.5V 1T	601.5	INT 3479 FLT 3670	INT 7140 FLT 7054	77	124.8
10x250	Rated Speed 500DDR	2-2-2-6 3.2V 1T	612.2	INT 3364 FLT 3557	INT 7093 FLT 7009	75	128.4
10x267 (2.67 GHz)	Highest CPU/Mem Performance	2-2-2-6 3.5V 1T	645.0	INT 3465 FLT 3630	INT 7552 FLT 7460	71	135.7

The top row of Performance results at 2.6V is included as a performance baseline. While VX cannot achieve 2-2-2 timings at stock voltage at DDR400, it can be coaxed easily into 2-2-2 performance at DDR400 with more voltage. With these modules, we reached an extremely stable DDR400 2-2-2-6 at 3.0V. We then maintained 2-2-2-6 timings all the way to DDR538, which required 3.6V for complete stability. The voltage requirements from 3.0 to 3.6 volts were very linear to Memory Speed.

The important results here are rows 2 to 6, where CPU speed is kept at 2.4GHZ and only the Memory Speed is varied. The performance differences you see in that range are a result of Memory Speed and timings only. In the case of VX, where memory timings also remain constant, the true impact of just memory speed can be clearly seen. It is not a huge difference in real-world benchmarks, but the increase is real nonetheless.

However, speed from 400 to 533 is not the only thing that is important with OCZ VX. Please take a look at VX performance in our later performance comparisons. Look at each of these speeds comparing VX to the best AMD TCCD and other memory that we have tested and you will see something very interesting. VX is faster at every speed than competing memory that we have tested. This means all 2-2-2 is not created equal, as VX is faster at every speed than the competition at 2-2-2.