M55e - MB speed

[chermesh]

Hi,
I would like to add memory to my overburdened M55e and I wonder what's the speed of my MB.
The exact type of my desktop is M55e CTO-9637.
I checked the manual, and it's not specified there.
I tried to find the information in the lenovo site (http://www-307.ibm.com/pc/support/site. ... MIGR-66959 and got thefollowing information:

2GB PC2-4200 (533MHz) DDR2 SDRAM 41X4253 R 1 CTO
512MB PC2-5300 (667MHz) DDR2 SDRAM 41X4255 R 1 CTO
1GB PC2-5300 (667MHz) DDR2 SDRAM 41X4256 R 1 CTO
2GB PC2-5300 (667MHz) DDR2 SDRAM 41X4257 R 1 CTO

So, is it 533MHz or 667MHz? How do I find out?

Ran