How accurate is System Requirements lab?

System Requirements lab is a website that analyzes your computer and tells whether you can run a specific game or not. For those who use it, I was wondering how accurate it is because some games I choose ex bioshock, say that the minimum processor I should have to run Bioshock would be a 2.4MHz but I have a 1.8MHz processor. It says that my processor is a 1.8MHz but it also states that my processor is rated as a 3.10MHz. So I was wondering if I were to buy bioshock or any game that requires higher then a 1.8MHz processor, would I be able to run it since my processor is rated at a 3.10MHz level according to system requirements lab. I mean they say I meet the processor requirement for Bioshock even though I have a 1.8GHz processor. So basically are system Requirements lab results accurate?

CPU Speed
Recommended: 2.2 GHz
You Have: 1.81 GHz Performance Rated at 3.10 GHz

The above is what the system requirements lab says.

Are you using a dual core or so?
Mine says:
You Have: 2.80 GHz Performance Rated at 5.04 GHz
I am using a Pentium D 2.8Ghz. And I know, it shows 5.04 due to Dual Cores.

nope I don't think so. I have AMD Sempron 3100+ 1.8GHz