NVIDIA nForce4 Ultra: Biostar's Performance Surprise

FSB Overclocking Results

Front Side Bus Overclocking Testbed
Processor:	Pentium 4 Smithfield LGA 775 840EE Dual Core 3.2GHz
CPU Voltage:	1.4825V (1.4000V default)
Memory Settings:	3-2-2-8 at 667MHz
Memory Voltage:	2.1V
SPP Voltage:	1.58V
FSB Voltage:	1.40V
Cooling:	Thermaltake Big Typhoon
Power Supply:	OCZ Power Stream 520
Maximum CPU OverClock:	250fsb x 17 (4250MHz) +33%
Maximum FSB OverClock:	255fsb x 16 (4092MHz) +27%

This board is an average overclocker when comparing it to the Intel 975X boards. At these overclock settings, the system was able to complete all of our benchmark test suites three consecutive times and run Prime95 and SuperPI without issue. We lowered the CPU multiplier to 14, but could not overclock past a 252FSB setting. We changed the LDT ratio to several different settings without success. These results continue the pattern in which we see with the nForce4 Intel Edition chipsets not reaching high FSB speeds, but being successful in overclocking the CPU at standard FSB settings.

We installed our 955EE CPU and were able to reach the highest CPU overclock recorded for our sample unit. The board performed flawlessly at this setting and reaching 4.55GHz on air with this chip is impressive. However, all attempts at lowering the multiplier and extending the bus speed past 1180MHz resulted in failure.

Updated 955EE Testing

We flashed the board to the latest bios, NFUIA210.BST, installed our 955EE CPU, and were able to reach a very stable 4.62GHz with air cooling. Our previous attempts at this multiplier resulted in a stable 4.50GHz at a bus speed of 1060MHz. We were able to boot the machine at 4.76GHz but could not complete our benchmark testing.

Memory Stress Testing

Memory stress tests look at the ability of the Biostar TForce4 U 775to operate at the officially supported memory frequencies of 667MHz DDR2, at the best performing memory timings that the Corsair CM2X512A-5400UL revision 1.3 will support.

Biostar TForce4 U 775 Stable DDR667 Timings - 2 DIMMs (2/4 slots populated - 1 Dual-Channel Bank)
Clock Speed:	200MHz (800FSB)
Timing Mode:	667MHz - Default
CAS Latency:	3
RAS to CAS Delay:	2
RAS Precharge:	2
RAS Cycle Time:	8
Command Rate:	1T
Voltage:	2.1V

The Biostar TForce4 was very stable with 2 DDR2 modules in Dual-Channel at the settings of 3-2-2-8 at 2.1V. We will now install all four available memory slots that result in more strenuous requirements on the memory subsystem than testing 2 DDR2 modules on a motherboard.

Biostar TForce4 U 775 Stable DDR667 Timings - 4 DIMMs (4/4 slots populated - 2 Dual-Channel Banks)
Clock Speed:	200MHz (800FSB)
Timing Mode:	667MHz - Default
CAS Latency:	3
RAS to CAS Delay:	3
RAS Precharge:	3
RAS Cycle Time:	8
Command Rate:	2T
Voltage:	2.10V

The Biostar TForce4 was completely stable with 4 DDR2 modules in Dual-Channel operation at the settings of 3-3-3-8, but required the command rate to be increased to 2T. We tried several combinations of memory settings at the 3-2-2-8 settings, but the board was not stable enough to complete our test suite.