Benchmarking configuration/reporting

[autoqs]

Just installed the GigabyteZ68AP-D3 bundle with 4Gb RAM and 2500K overclocked to 4.4Ghz.
Running Windows7 64-bit
However I am getting this in the processor information line from the standard windows System Information box

Processor: Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz 5.8GHz

From a DOS prompt I get:
>wmic cpu get name,CurrentClockSpeed,MaxClockSpeed
Name CurrentClockSpeed MaxClockSpeed
Intel(R) Core(TM) i5-2500K CPU @3.30GHz 4176 5801

Q1
What is this 5.8Ghz about ? Obviously its nothing to do with clock speed ?

CPU-z is almost constantly sitting at
Core Speed = 1604.8MHz
Multiplier = 16x

I have read about SpeedStep and the efect it can have on the reported CPU speed.
Q2.
Is it worth trying to stop SpeedStep when doing benchmarking ?.

However even when running e.g. the 64-bit "performance test" utlity, CPU-z still sits there at around 1600.

Q3 Is CPU-z actually the best thing to be using when running a benchmark ?

Q4. Is there another benchmark utility that I can use which will also allow me to compare results with other similar system builds(processor and mobo) ?

Opinions welcome ....

 

[wazza300]

windows never gets the correct oc speed,best to use other software like cpu-z and aida64 ect,it will give you correct cpu usage at idle/load

 

[j.col]

Not really a benchmark, but you can try Intel burn test,
This will stress test your cpu.
Have cpu-z open at same time, and you will then see the true readings.
Also you should have a gflop score in IBT of 90-120 gflops