Overclocking Genie

Starting Configuration

First I ran the PC on its standard clocked configuration, namely:-

• multiplier: 7x
• FSB: 100 Mhz
• Voltage: 1.65

Being an intel CPU, the processor is locked to the 7x multiplier and the only scope for overclocking come from increasing the FSB beyond spec. The results obtained for this (SiSoft Sandra 2001) were 1877 (MIPS) and 942 (MFLOPS). MIPS are Millions of Instructions Per Second (an integer unit test) and MFLOPS are Millions of Floating Point Operations Per Second (a test of the Floating point unit).

Overclocking

The first setup tried was:

• Multiplier: 7x, FSB 105 Mhz, Voltage 1.65

On these settings the PC successfully passed POST (Power On Self-Test) but windows would not boot. The Voltage (CPU core Voltage) was increased to 1.70V. This principle was followed to its limit with another 0.05V increase when needed for successful booting. The following configurations were succesful:-

• Multiplier: 7x, FSB 105 Mhz, Voltage 1.70
• Multiplier: 7x, FSB 110 Mhz, Voltage 1.70
• Multiplier: 7x, FSB 115 Mhz, Voltage 1.70
• Multiplier: 7x, FSB 120 Mhz, Voltage 1.75 – Unstable!

Results

The following table shows the benchmark results for the different speeds:-

Speed	Multiplier	FSB	Voltage	MIPS	MFLOPS	Difference
700	x7	100	1.65V	1877	942	0%
735	x7	105	1.70V	1979	994	5%
770	x7	110	1.70V	2059	1044	10%
805	x7	115	1.70V	2143	1086	14%
840	x7	120	1.75V	2326	1179	23%

As can be seen, there is a great increase in CPU performance, culminating on the high results for the overclock at 840MHz. Whilst this setting is not fully stable it is likely a fast stable result can be found between an FSB of 115 and 120 to yield a CPU speed increase of approximately 15-20%. This is an impressive result considering the only cooling being applied to the CPU is standard Intel Heatsink and fan supplied with the processor.

10/9/01