CPU Speed Not As Specified

[William Zeng]

I added a new 64m bytes PC100 RAM to my 133MHz system using a Pentium III
533MHz CPU runing at 133MHZ at 4 times clock ratio. In order to make it
compatible with the system and the existing PC133 RAM, I have to ajust the
frequency of the system to 100MHz. I hope to run the CPU at similar speed as
specified, so I adjusted the clock ratio to 5 to make the CPU speed as
500MHz. These adjustments are all OK in BIOS setup and the newly added RAM
does work well with the system. However, when I started up my Windows XP
Professional, I found the CPU speed changed to 400MHz, that means it runs on
the ajusted system frequency (100MHz) at the old clock ratio of 4 times. Any
one can tell me how this happens and how to make a higher CPU Speed while
the system frequency is turned down.

Thanks.

William

 

[GHalleck]

I added a new 64m bytes PC100 RAM to my 133MHz system using a Pentium III
533MHz CPU runing at 133MHZ at 4 times clock ratio. In order to make it
compatible with the system and the existing PC133 RAM, I have to ajust the
frequency of the system to 100MHz. I hope to run the CPU at similar speed as
specified, so I adjusted the clock ratio to 5 to make the CPU speed as
500MHz. These adjustments are all OK in BIOS setup and the newly added RAM
does work well with the system. However, when I started up my Windows XP
Professional, I found the CPU speed changed to 400MHz, that means it runs on
the ajusted system frequency (100MHz) at the old clock ratio of 4 times. Any
one can tell me how this happens and how to make a higher CPU Speed while
the system frequency is turned down.

Thanks.

William

The Intel P3 processors are multiplier-locked. It does
not matter what is the setting for the multiplier in the
motherboard. With the FSB running at 100 MHz and the P3
multiplier locked at 4.0, the resulting speed is 400 MHz.
To run at 533 MHz, remove the PC100 RAM and replace with
PC133 (or faster) compatible RAM (4.0 times 133 MHz yields
533 MHz.)

 

[Mike]

You will probably find that if you had just installed the RAM without
changing any settings, that it would have run perfectly well.. the only
difference would have been that all of the RAM would have operated at
100mhz.. reset to original settings and try it..

 

[William Zeng]

Thanks, GHalleck. I believe what you said is true.

William