System setup and notes
Hardware and Software
Test Platforms
| System | Intel Pentium System | |
| Processor | Pentium Extreme Edition 955 @ 965 speed (Presler core) | |
| Mainboard | ASUS P5WD2-E Premium | |
| Memory | 1GByte (2x512MB) Generic PC4300 1GByte (2x512MByte) Corsair XMS2-5400UL 1GByte (2x512MByte) Corsair TWIN2X1024-8500 |
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| Timings | 5-5-5-15 @ DDR2-533 3-2-2-8 @ DDR2-667 5-5-5-15 @ DDR2-1066 (both single- and dual-channel) |
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| BIOS Version | BIOS 0302 (17/1/2006) | |
| Disk Drive | 160GB Western Digital PATA | |
| Graphics Card | ATI RADEON X1800 XL 256MB PCIe, CATALYST 6.2 set | |
| Operating System | Windows XP Professional, SP2 32-bit | |
| Mainboard Software | Intel INF Update Utility 7.2.2.1006 | |
Benchmark Software
Memtest86+ v1.65
ScienceMark 2.0 (21st March 2005)
DivX 6.1 encoding test. 1700kbps, Insane Quality, 416MB DV file
DOOM 3 v1282 - 1024x768 Medium Quality
Far Cry v1.33 - 1024x768 High Quality
Notes
The reason to choose ASUS' P5WD2-E Premium motherboard lies with its excellent BIOS. You are able to select a number of memory ratios when using a 1066MHz FSB CPU, as shown below.
So, without having to overclock the CPU any, we were able to run the TWIN2X1024-8500 pack at its rated frequency. Further options allowed us to toggle latencies and voltages, as well.
Our test is to see if these modules' ultra-high speed impacts positively on performance when compared to lower-rated memory.
To this end, we decided to benchmark the TWIN2X1024-8500 set against Corsair's own TWIN2X1024-5400UL set, rated to run at DDR2-667 speeds with extra-low 3-2-2-8 latencies. We also added in a pack of generic RAM that used the '8500's latencies but at half the speed. Noted earlier, this set provides enough bandwidth in single-channel mode to satiate the Intel Pentium Extreme Edition's memory requirement, so what benefit, if any, does dual-channel operation bring? That's the question we'll attempt to answer.
Summing up, and considering that we can run any of the above speeds without having to change the CPU's speed in any way, we ran the following settings:
Intel Pentium Extreme Edition 955 @ 965 (3.74GHz) - 1068.5MHz FSB - Corsair TWIN2X1024-8500 @ 1068.5MHz - 5-5-5-15 latencies - dual channel.
Intel Pentium Extreme Edition 955 @ 965 (3.74GHz) - 1068.5MHz FSB - Corsair TWIN2X1024-8500 @ 1068.5MHz - 5-5-5-15 latencies - single channel.
Intel Pentium Extreme Edition 955 @ 965 (3.74GHz) - 1068.5MHz FSB - Corsair TWIN2X1024-5400UL @ 667.8MHz - 3-2-2-8 latencies - dual channel.
Intel Pentium Extreme Edition 955 @ 965 (3.74GHz) - 1068.5MHz FSB - Generic DDR2 @ 534.2MHz - 5-5-5-15 latencies - dual channel.
No problems in getting the modules up to speed. An error-free 30-minute Memtest86+ v1.65v bashing ensured basic stability at the prescribed frequencies and timings.
There's no JEDEC standard that covers DDR2 memory operating at >PC6400 speeds, so Corsair programs in the SPD table to reflect this.
