High Speed DDR2: Buffalo and Crucial Deliver 1000+

Crucial PC2-8000 C5: Stock Memory Performance

While the Intel platform does not really allow for easily testing different memory speeds at the same CPU speed, our test Asus motherboard does provide a wide range of memory ratios that match available DDR2 memory. This allows end-users to select the memory ratio that matches their DDR2 memory speed if they wish, or to choose a speed value over or below the rated memory speed. For those reasons, we first tested all of the stock ratios at the fastest stable timings we could achieve at the given ratio. With ratios, processor speed remains constant at 3.46GHz and memory speed is varied by choosing different ratios.

Crucial (Stock Memory Ratios) - 2x1GB Double-Bank
CPU Ratio at 3.47 GHz	Memory Speed	Best Timings (Voltage)	Far Cry (fps)	Sandra Unbuffered	Sandra Buffered	SuperPI 2M Mod 1.5 (seconds)	HL2 Lost Coast (fps)	Quake 4 (fps)
(4:3)	400 DDR2	3-2-2-5 1.8V	60.8	INT 2820 FLT 2827	INT 5519 FLT 5548	88.6	82.6	68.8
(1:1)	533 DDR2	3-2-3-8 2.0V	61.4	INT 3494 FLT 3521	INT 6459 FLT 6467	86.2	87.9	73.4
(4:5)	667 DDR2	3-3-3-10 2.1V	62.2	INT 3961 FLT 4004	INT 6571 FLT 6565	85.5	88.7	75.7
(2:3)	800 DDR2	4-3-4-11 2.1V	62.6	INT 4211 FLT 4252	INT 6722 FLT 6702	84.9	89.5	76.5
(1:2)	1067 DDR2	4-4-5-14 2.35V	65.7	INT 4560 FLT 4632	INT 6836 FLT 6843	83.9	91.6	79.6
(3:5) OC 300x13	1000 DDR2* *Rated Speed	4-3-4-12 2.2V	73.3	INT 4989 FLT 5064	INT 7671 FLT 7658	74.9	101.3	87.8
Highest Mem Speed (1:2) OC 271x13	1084 DDR2	5-4-5-15 2.35V	66.2	INT 4521 FLT 4587	INT 6905 FLT 6898	83	91.8	80.3

Since the Crucial Ballistix is also rated at DDR2-1000, the 1000 speed was tested for performance. To achieve that speed the 889 memory speed was selected at the standard 1066 FSB (266 setting quad pumped). The FSB was then overclocked to 300 (1200 FSB) resulting in a memory speed of DDR2-1000. The Ballistix performed much better than the rated timings of 5-5-5-15. The Ballistix memory was completely stable at DDR2-1000 at 4-3-4-12 timings. This matches the best memory timings we have found with DDR2-1000 as the timings are the same as OCZ EL PC2-8000 XTC.

While the Crucial generally matched the wide memory speed range of OCZ EL, the required memory timings at most memory speeds were a bit slower than those required by OCZ. This resulted in performance that was slightly slower than OCZ at most speeds. While Crucial, Buffalo, and OCZ all use the same Micron memory chips, each manufacturer "speed-bins" the chips using their own internal procedures. They also choose the PCB to use with the memory chips, and program the SPD for best performance. These additional steps result in some differences in performance with a given chip such as you are seeing in this review. Apparently OCZ squeezes a bit more performance out of these chips, although the performance advantage for OCZ is small.

The Crucial PC2-8000 topped out at DDR2-1084, which is slightly below DDR2-1100 achieved with the Buffalo and OCZ. However, the slower memory timings required at the top of the performance range make the speed around 800 to 1000 the best-performing range with any of these three DDR2-1000 rated memories. In that range the Crucial Ballistix is very competitive.

At the rated speed of DDR2-1000 the CPU is running at 13x300 or a 1200FSB. The CPU overclock and higher bus speed certainly contribute to the higher performance at DDR2-1000. Comparing non-overclocked CPU and bus speeds, the memory performance curve is linear, generally improving as speed increases. Where faster memory timings are possible (lower memory timing settings) there is a comparable improvement in memory performance.