915 Motherboard Roundup: Socket 775 for the Rest of Us

MSI 915P Neo2 Platinum: Overclocking and Stress Testing

FSB Overclocking Results

MSI added the Intel Speedstep feature to the version 1.5 BIOS. This allows Prescott processors to run at either their stock ratio or at a reduced 14X ratio for cooler operation or FSB overclocking.

Front Side Bus Overclocking Testbed
Processor:	Pentium 4 Prescott LGA 775 560 ES (2.8GHz-3.6GHz)
CPU Voltage:	1.425V (1.3875V default)
Cooling:	Thermaltake Jungle 502
Power Supply:	OCZ Power Stream 520
Maximum CPU OverClock:	223x18 (4014MHz) +12%
Maximum FSB OC:	285FSBx14 (+43%) 258x14 on Auto PCIe (+29%)

Overclocking on the MSI 915P is an interesting experience. Using the Auto PCIe setting, we reached a maximum FSB overclock of 258x14 or 15, which is very similar to results found on the Abit AG8. The MSI has additional adjustments for PCI Express and PCI frequencies, however, that are not available in the same type and ranges on other 915P boards. By fixing PCI speed and setting PCIe to a fixed frequency of 120 (the maximum that the SATA drives could handle), we reached a stable overclock of 285x14 (3990) or +45% on the MSI. You can reach just about any overclock that might work on the MSI by manipulating PCIe and PCI frequencies, but it requires a bit more work that the elegant Asus algorithms that are of part of the Asus "Auto PCIe" choice in BIOS.

Working at the stock 18X ratio, an overclock of +12% is possible, raising the 3.6GHz Prescott to 4.0Ghz and a very hot heatsink/fan and north bridge heatsink. As we have stated before, any stable long-term overclocks above 3.9GHz on Prescott will require a serious cooling solution with more power than the best air cooling can deliver. For more information on how overclocks can be managed on the 915/925X, please check Breaking Intel's Overclock Lock: The REAL Story.

Memory Stress Test Results:

MSI designed the 915P Neo2 Platinum to use DDR2 memory. The memory stress test measures the ability of the MSI to operate at its officially supported memory frequency (533MHz DDR2) at the best performing memory timings that Crucial/Micron PC2-4300U will support. Memory stress testing was conducted by running DDR2 at 533MHz (stock 3:4 ratio) with 2 DIMM slots operating in Dual-Channel mode.

Stable DDR533 Timings - 2 DIMMs (2/4 DIMMs - 1 Dual-Channel Bank)
Clock Speed:	266MHz
Timing Mode:	3:4 (200:266 - Default)
CAS Latency:	3.0
Bank Interleave:	Auto
RAS to CAS Delay:	3
RAS Precharge:	3
Cycle Time (tRAS):	10*
Command Rate:	N/A

*SPD (Auto) timings for DDR2 are normally 4-4-4-12 at DDR2-533. A tRAS setting of 12 is normal. We ran a series of tests to measure memory bandwidth, and found that the tRAS setting made very little difference in the performance of DDR2. The most effective range of tRAS was 8 to 13 for DDR2 on the 925X chipset, so a tRAS of 10 was chosen for benchmarking.

The MSI 915P Neo2 Platinum was completely stable with 2 DIMMs in Dual-Channel at the DDR2 settings of 3-3-3-10 at 1.8V default voltage. These are much faster settings than the DDR2 SPD and rated timings of 4-4-4-12.

Filling all four available memory slots is more strenuous on the memory subsystem than testing 2 DDR2 modules on a motherboard.

Stable DDR533 Timings - 4 DIMMs (4/4 DIMMs - 2 Dual-Channel Banks)
Clock Speed:	266MHz
Timing Mode:	3:4 (200:266 - Default)
CAS Latency:	3.0
Bank Interleave:	Auto
RAS to CAS Delay:	3
RAS Precharge:	3
Cycle Time (tRAS):	10
Command Rate:	N/A

The MSI 915P was the only motherboard in the roundup that was also completely stable at the same 3-3-3-10 memory timings with 4 DIMMs at 1.8V. We did find that an increase in voltage to 1.9V improved stability of 4 DIMMs in the MSI when running Super Pi.