Dual Xeon vs Core2 6400 @ 2.13GHz

[Erudition]

Hi Admin!

I performed the test on a dual Xeon 3.0Ghz (single core, with hyperthreading), used latest version of software:
CPU - Integer Math: 180.9
CPU - Floating Point Math: 534.3
CPU - Find Prime Numbers: 177.3
CPU - Multimedia Instructions: 0.7
CPU - Compression: 2504.5
CPU - Encryption: 10.2
CPU - Physics: 66.2
CPU - String Sorting: 1122.7
CPU Mark: 951.1
Number of CPU: 2
Cores per CPU: 1
CPU Type: Intel Xeon 3.00GHz
CPU1 Speed: 3000.1 MHz
CPU2 Speed:
Cache size: 1024KB

Then I performed the test on a Core2 6400 @ 2.13GHz (dual core no hyperthreading)
CPU - Integer Math: 191.2
CPU - Floating Point Math: 518.4
CPU - Find Prime Numbers: 431.5
CPU - Multimedia Instructions: 3.6
CPU - Compression: 2341.8
CPU - Encryption: 6.7
CPU - Physics: 88.4
CPU - String Sorting: 1214.0
CPU Mark: 1268.8
Number of CPU: 1
Cores per CPU: 2
CPU Type: Intel Core2 6400 @ 2.13GHz
CPU Speed: 2131.1 MHz
Cache size: 2048KB

Why the small difference in CPU performance?
Thanks!

[David (PassMark)]

The Xeon is an older CPU, but you have 2 of them at higher clock speed.

But desipte the have twice as many CPUs at a higher clock speed the Core 2 was 27% faster than the dual Xeon. Which I think is about normal. The newer Core 2 are significantly quicker. What were you expecting?

Are you running the same O/S on both machines (32bit vs 64bit)?

[Erudition]

I am running both on XP SP3- 32-bit.
I actually didn't expect the 6400 to outrun the Xeons, due to clockspeed and HyperThread support in the Xeons.

[David (PassMark)]

I am guessing these are probalby the 90mn Nocona Xeons from 2004 with 1MB cache. Now ~6 years old. These were based on the Netburst microarchitecture, first released in the year 2000. They had a long pipeline will allowed high clock speeds, but were inefficient (by todays standards).

The Core microarchitecture, released in July 2006. (Which has since been replaced by the Nehalem microarchitecture of the Core i7's).

So the Nocona Xeons are now pretty old, hot and slow, compared with current CPUs.