Intel D975XBX: Intel brings their Bad-Axe to Market

FSB Overclocking Results

Front Side Bus Overclocking Testbed
Processor:	Pentium 4 Smithfield LGA 775 840EE Dual Core 3.2GHz
CPU Voltage:	1.5125V (1.4000V default)
Memory Settings:	3-2-2-8 at 667MHz
Memory Voltage:	2.2V
MCH Voltage:	1.60V
ICH Voltage:	Default
Cooling:	Thermaltake Big Typhoon
Power Supply:	OCZ Power Stream 520
Maximum CPU OverClock:	200fsb x 20 (4000MHz) +25%
Maximum FSB OverClock:	260fsb x 15 (3900MHz) +30%

This board is a decent overclocker considering the limited settings available in the BIOS. 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 were able to overclock the FSB to 260 at the 16x multiplier, which resulted in CPU operation of 4160MHz, but we could not complete our test suite. We also were able to raise the CPU multiplier to 21 at the 200 FSB setting, which resulted in the CPU operation of 4200MHz, but it could not run any tests reliably.

We tried two other boards, but we did not have success in increasing the CPU multiplier past 20 or utilizing a combination of the CPU multiplier and the FSB frequency override setting past the reported numbers. Even though this particular CPU has reached 4.4GHz, we could not pass the 4.0GHz mark and maintain stability or complete our test suite. We will be receiving a retail board shortly and will re-examine the overclocking ability of the board with our 840EE, 950D, and 955EE processors.

Memory Stress Testing

Memory stress tests look at the ability of the Intel D975XBX to 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.

Intel D975XBX 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
Voltage:	2.1V

The Intel D975XBX 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 are usually more strenuous on the memory subsystem than testing 2 DDR2 modules on a motherboard.

Intel D975XBX 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:	2
RAS Precharge:	3
RAS Cycle Time:	8
Voltage:	2.2V

The Intel D975XBX was completely stable with 4 DDR2 modules in Dual-Channel at the settings of 4-2-3-8 and needed the voltage increased to 2.2V. We tried several combinations of memory settings at the CAS Latency of 3, but the board was not stable enough to complete our test suite. This is the first i975x board that we have tested that did not allow a CAS Latency of 3 in our testing with 4 DDR2 modules.