1333 Mhz ram in a MBP with 1066Mhz Fsb

Will 1333Mhz ddr3 ram modules pulled from my early 2011 MPB work in a Mid 2009 13" MBP with 1066Mhz front side bus?

Short answer: no. The reason is that Macs are very fussy about memory and it's always best to use what originally was installed from the factory as to speed and type.

So the long answer seems to be different.

I figured no harm in trying since it was apple ram.

I installed it on Saturday and have been running the macbook hard since then with no apparent issues.

The SPD values must be compatible with the system bios. System information describes the ram as 1333MHz and shows the front side bus at 1.07GHz.

Obviously there won't be a performance uplift due to the "faster" ram specs but there is a nice uplift from doubling the ram in the macbook.

Of course there will not be a 'performance uplift'. Do you expect one? The mobo will run at its speed of 1066MHz and Macs do not have BIOS rather firmware. You will know the problem in a week or two should you get panic attacks, directions in several language to restart.

Certain models act differently with faster or even slower memory modules than the factory stock. If it seems to be running OK, keep an eye on it as Harry said - you may get Kernel Panics. But if not, press on.

On a PC, (depending on the BIOS) you can usually compensate for faster memory by changing CAS and RAS settings. I've done that myself several times, however, with Macs there's no way to compensate which is why we always recommend sticking to the factory spec.