64Bit vs 32bit CPU numbers... very different

[pv9685]

So, this is one of those important questions... The 32bit and 64bit numbers are not the same - my CPU will get 2700-2800 on a 32bit OS, or in a 64bit OS using the 32bit program. Under a 64 bit OS with the 64 bit program it gets around 3600. Which is more likely to be acurrate? Whenb I view the CPU ratings list, is it just a mix of the two?

Perhaps this is why I have noticed that older AMD Athlog 64 X2 CPUs are getting faster and faster - a CPU that was once in the 800-900 range is now 1200-1300! hmmm...

So is this likely to be a) the fact that it would be impossible to make the two tests produce exactly the same numbers; b) the fact that CPU's may be better optimized for one set of instructions vs the other; or c) both?

[David (PassMark)]

Identical high level operations are performed in both the 32bit and 64bit software.

But the 64bit CPU running 64bit native code does some of them more efficiently.

See this old post for an explanation of why 64bit can be quicker when you have native 64bit code.
Comparing 64bit and 32bit CPU benchmark results

The numbers in the benchmark charts are a mix of 32bit and 64bit.

CPUs themselves won't get faster over time. But the certainly more and more people are switching to 64bit operating systems. Which will lift the results of 64bit capable CPUs compared to 32bit only CPUs.