E6300 upgrade to E6600 freq question

[raster43]

I have a Compaq/HP DC7700 workstation that came stock with an E6300, 1.86ghz, 2mb, 1066fsb. Compaq oem heatsink, not Intel. 2 gb ram. Win XP 32bit. So, no Oc'ing here.

My question is more out of curiousity , not a problem. When I ran the cpu test only, on the e6300, the "effective" frequency was shown as 1.861, running the test w/2 processes. As I would expect.

2 days ago, when I installed the E6600, 2.4ghz, 4mb, 1066, I then repeated the test. As expected, the test results were about 22% better on average. However, the frequency was shown as 1.593 . Reason for this ? BTW Real Temp and Intel's TAT(1.600) show this as well. Yet, Intel's CPUID shows it as 2.4 !

Now, if I rerun the test with the processes set to 4, then Performance test shows the freq as 2.393. All other test results the same. BTW, even control panel's #, in system info, was displaying 1.593 until today, when it jumped up to 2.4.

Lastly, the e6300 core temps @idle were ~35 d C (using Intel's TAT).
The new e660 measures ~18 d C ! Now granted I used Arctic's Ceramique thermal paste on the install vs whatever HP uses as paste. But that's some big drop. I also tested the sensors, using Real Temp, and they are fine. Any ideas why such a low core temp ? ( ambient room temp ~ 62 D FH)

Lastly, If I run a 100% workload test, under TAT, the freq then displays 2.4 and temp 32 d C.

Thanks to any insight to all of this and Happy Thanksgiving to all !

Here's 2 screenies of a test I just did, using 2 processes, and the eff freq is 2.93 very bizarre. Test results typical for this cpu? :

[David (PassMark)]

The low Mhz speed was probalby the CPU throttling back (to save power, and generate less heat) under light load.

[raster43]

Thanks for the response, which makes sense. However, was the e6300 not capable of this ?

[David (PassMark)]

It would think that in theory the E6300 could throttle back. Back given it is already running so slowly the crietia for thottling are probalby different (e.g. maybe just on overheating). You would need to do some deep reading of the Intel technical documents to know the full story.

[raster43]

It would think that in theory the E6300 could throttle back. Back given it is already running so slowly the crietia for thottling are probalby different (e.g. maybe just on overheating). .

Thanks ! That makes sense, plus, I would think, the additional 2mb of L2 cache.

Edit : Great program BTW !!