[fcui21]

My BIOS settings indicate my CPU Speed is 3.0GhZ but the clock speed shows 266MHz (max). What is the difference between the two and how can I make sure I have reached the maximum speed for my CPU? I have an intel Pentium 4 (Northwood) model SL6WK which has a FSB of 800MHz. Also, separate topic but related...DDR in BIOS settings shows 333MHz...I have a DDR2 PC5300 memory type.

[peterhuang913]

The speed for the SL6WK is 3.0GHz. It is suppose to run at 800MHz FSB. Dunno about the 266. Download and run CPU-Z. Take a screenshot and post it here.

DDR2 PC5300 is also known as DDR2-667. It has an I/O bus clock of 333MHz, which is correct with what you're showing us.

[Blind_Arrow]

266MHz is the speed of the bus, as Intel are Quad Pumped, so effectively makes 266X4 = ~1066MHz which maximum (theoretical) your processor can have. but, yours is Northwood, and they had 200Mhz (200Mhz x 4 = 800Mhz FSB). your motherboard has capability of speeds up to 1066MHz (266 x 4) as told before.

now CPU speeds are calculated by the Clock and Multiplier, like in your case, your CPU is showing 3GHz (3000/200 = 15) or 200Mhz (FSB) x 15 (Multiplier) = 3000Mhz / 3Ghz

Understood!