Intel Motherboards: Can a Diamond beat a Royal Flush?

MSI P4N Diamond: Overclocking

Front Side Bus Overclocking Testbed
Processor:	Pentium 4 Prescott LGA 775 840EE Dual Core 3.2GHz
CPU Voltage:	1.4V (1.350V default)
Cooling:	Intel Stock Cooler
Power Supply:	OCZ Power Stream 520
Maximum CPU OverClock	238FSB x1 6 (3808MHz) +19%
Maximum FSB OC:	0FSB x 14 (0MHz)

With a stock multiplier, the P4N Diamond reached an overclock of 238x16 or 3808MHz. Unfortunately, once we changed the multiplier, the system would disable the second core. We tested several BIOS versions from MSI, but the results remained the same. This only reinforced our findings that the nForce4 SLI Intel Edition chipset did not fully support the entire Pentium D processor lineup. To further check, we tried the Intel Pentium D 820, a low-cost dual-core dual-core Intel processor very popular with overclockers. The MSI board would not run the 820 in dual-core mode, switching it to single core operation only.

We sent our test findings to both MSI and NVIDIA for resolution. NVIDIA responded and stated both issues are a known limitation in the current NVIDIA chipset for Intel SLI and will be fixed in future product releases. NVIDIA added that the Intel Pentium D 820 was not released when the NVIDIA Intel SLI package was designed and they did not validate the chipset. They did not believe at the time it was likely buyers of a top-end board with the NVIDIA nforce4 Intel Edition SLI chipset would use it with a value dual-core processor like the 820. However, the Pentium D 820 problem will also be fixed in future NVIDIA chipset revisions.

While we were able to reach these OC levels with the Intel HSF, the long-term stability of the system at these speeds is very suspect. After running several tests, the system began throttling, alternating between stock speed and reduced speed due to overheating. There is no doubt that the CPU can do these speeds or better, but it will require an alternative cooling system.

Memory Stress Testing

Memory stress tests look at the ability of the MSI P4N Diamond to operate at the officially supported memory frequencies of 533MHz and 667MHz DDR2, at the best performing memory timings that the Patriot Extreme Performance PEP21G5600+XBL will support.

MSI P4N Diamond Stable DDR533 Timings - 2 DIMMs (2/4 slots populated - 1 Dual-Channel Bank)
Clock Speed:	200MHz (800FSB)
Timing Mode:	533MHz - Default
CAS Latency:	3
RAS to CAS Delay:	2
RAS Precharge:	2
RAS Cycle Time:	4
Voltage:	1.8V
Command Rate:	1

The MSI P4N Diamond was completely stable with 2 DDR2 modules in Dual-Channel at the settings of 3-2-2-4 at 1.8V.

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

MSI P4N Diamond Stable DDR533 Timings - 4 DIMMs (4/4 slots populated - 2 Dual-Channel Banks)
Clock Speed:	200MHz (800FSB)
Timing Mode:	533MHz - Default
CAS Latency:	3
RAS to CAS Delay:	2
RAS Precharge:	2
RAS Cycle Time:	4
Voltage:	1.95V
Command Rate:	1

The MSI P4N Diamond was completely stable with 4 DDR2 modules in Dual-Channel at the settings of 3-2-2-4, but the voltage had to be increased to 1.95V.

We will now increase the memory frequencies to 667MHZ to see what effect this change has on the memory timings and stability of the board.

MSI P4N Diamond Stable DDR677 Timings - 2 DIMMs (2/4 slots populated - 1 Dual-Channel Bank)
Clock Speed:	200MHz (800FSB)
Timing Mode:	667MHz - Default
CAS Latency:	4
RAS to CAS Delay:	3
RAS Precharge:	3
RAS Cycle Time:	8
Voltage:	1.9V
Command Rate:	1

The MSI P4N Diamond was completely stable with 2 DDR2 modules in Dual-Channel at the settings of 4-3-3-8 at 1.9V and leaving the Command Rate at 1.

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

MSI P4N Diamond Stable DDR667 Timings - 4 DIMMs (4/4 slots populated - 2 Dual-Channel Banks)
Clock Speed:	200MHz (800FSB)
Timing Mode:	667MHz - Default
CAS Latency:	4
RAS to CAS Delay:	3
RAS Precharge:	3
RAS Cycle Time:	8
Voltage:	1.9V
Command Rate:	2

The MSI P4N Diamond was completely stable with 4 DDR2 modules in Dual-Channel at the settings of 4-3-3-8 at 1.9V, but the Command Rate had to be switched to 2. This resulted in a 1 to 3% decrease in benchmark scores during testing.