Question about CPU Speed

Five and a half years ago, someone built me a barebones PC. It has an EliteGroup P6SET-ML motherboard with onboard audio and video and 32 KB primary memory cache and 128 KB secondary memory cache. The CPU/SDRAM bus frequency is 66/66 MHz. It has a 500 MHz PPGA (socket 370) Celeron processor and one stick of PC100 128 MHz SDRAM.

Earlier today I noticed the following in the BIOS & CPU Features Setup:

CPU Internal Core Speed: 233 MHz
CPU/SDRAM Bus Frequeny: 66/66 MHz
CPU Core: Bus Freq.Multiple: 3.5x

Okay, I know that 3.5 times 66 = 231 (close enough to the 233 listed).
But the speed of my processor is 500 MHz! What's going on? Is there a difference between CPU speed and CPU Internal Core Speed?

TIA. (Please be gentle; this is my first post!)

 

I'm pretty sure that there is no difference :-S

However, I don't think there will be a noticeable difference in performance between those two clock speeds

 

If you mean between 231 and 233, I definitely agree! But what about 500?! Shouldn't the value be close to 500? Should I just change the multiplier to 7.5?

 

500MHz is likely an approximation.
Your true clock speed is 233MHz, and your CPU is likely "double-pumped" meaning 2 instructions are sent per clock cycle for an effective clock speed of 466MHz (rounded to 500MHz).

For a better explanation, please see the Overclocking Guide which explains CPU speeds in detail.

 

The more I'm looking into this, the more I'm coming to the conclusion that the system builder set the CPU core speed at too low a level in the BIOS. I looked at that page you listed and also found http://www.directron.com/fsbguide.html (especially Part IV) and see no evidence that the Celeron-A (aka Mendocino) is double-pumped.

Still, I don't get why once I'm in Windows and measure the CPU speed there, it's either at or near 500 MHz.