Actual Speed CPU is running at?

[realelectronics]

I installed an Intel SL95V 3.4 Pentium D in my desktop and the computer starts up fine but when I run CPU-Z
it recognizes the CPU correctly but it reports it running at 2394.1 MHz with a multiplier of 12 and bus speed of 199.5 MHz.
Also, Speccy reports each core as as 2.4 GHz with a multiplier of 12

I ran Intel Processor ID Utility it reports the expected speed as 3.4 GHz and each core as 3.4GHz

Also, I used x86test from Ultimate Boot CD which runs on system startup. It reports the speed as 3.3915 GHz (17.0 x 199.50 MHz).

So I am confused about what speed it is really running at.
My PC is a Dell Dimension E510 Dell DM051 series Service Tag 64NMMB1 Dell BIOS A07 1/8/07 Intel Chipset 945G Express. The main board is 0HJ054

The system is running XP Pro 32 bit SP 3.

Any ideas what is going on? Does it have anything to do with XP?

[David (PassMark)]

None of the software nor hardware you mention is developed nor supported by us. So maybe you might want to contact the developers of the respective software?

Maybe you are just seeing Intel "SpeedStep" dropping the clock speed under light load.