32 vs 64 bit performance

Question

Trying to compare the performance results of 32 vs 64 bit.
The performance of 64 bit is slower compared to 32 bit, the difference is atleast twice.

Any reasons why it could be so? Any directions or pointers?

The db is MS SQL server 2008 on Windows Server 2008 Standard, SP1.
The middlewares are COM servers.
performance testing is done using VSTS.

32 bit Server:
OS : Windows Server 2008 Standard, SP2 (32-bit)
Processor : Intel Xeon CPU 5110 @ 1.60 GHz 1.60 GHz
Number of processors: 2
Memory(RAM) : 4.0 GB

64 bit server:
OS : Windows Server 2008 R2 Standard, SP1 (64-bit)
Processor : Intel (R) Xeon (R) CPU 5110 @ 1.60 GHz 1.60 GHz
Number of processors: 2
Memory(RAM) : 4.0 GB

Thanks,

Saleem

Answer 1

the difference is atleast twice -? Can  you post the difference figures as well?

Answer 2

For a 64bit System you need a lot of more Memory