Hyper threading option not available in BIOS

Then why do programs say that HT is available? And my order says, 2.4 Ghz processor with HT ?

It says that hyperthreading is available but not enabled in various programs, specifically 3dMark05. When i bought the computer 2 years ago, it said that HT was available.

It turns out that Dell sold me the computer with a 2.4 processor with HT technology, but with a motherboard that doesn't allow it. I need an 800 Mhz FSB to enable HT with my processor. Which is ridiculous, because why would they put HT processors in a computer with a 533 Mhz FSB?

I have no idea.  All I know is that your system can either have a 400 Mhz front side bus, in which case there is not P4 that supports hyperthreading, or a 533 Mhz front side bus, in which case the only CPU that has hyperthreading is the 3.06 Ghz.  There are 2.4 Ghz CPUs that do support hyperthreading, but these will only work in systems with an 800 Mhz front side bus. 

Steve

It was available, but only if you ordered the system with a 3.06 Ghz CPU.  Intel makes the CPU.  Intel says your CPU is not a hyperthreading CPU.

Steve

The P4 2.4 Ghz CPU is not a hyperthreading enabled CPU.  You need a CPU that has hyperthreading before it can be enabled in the BIOS.

See the following:

http://www.intel.com/products/ht/hyperthreading_more.htm

The only 533 Mhz CPU that supports hyperthreading on your system is the 3.06 Ghz CPU.

Steve

you do not have HT.

a) 2.4ghz processors w/ HT are based on the prescott core, which your processor is not (rev d+)
b) these programs are reporting you have HT available because in the northwood core (533mhz), there is a checkbit that is enabled that these programs look at to determine if you have HT or not. Only the 3.06ghz northwood has HT. It was once believed that the lower processors did have HT, just turned off internally by Intel. This has yet to be proven.