T61p RAM upgrade: PC6400 CL6? Or PC5300 CL5 ?

[hellosailor]

I was going to order 2x2GB RAM to upgrade my T61P (from 2x1GB) but as usual it isn't so easy. I see Newegg sells only PC5300 CL5, but Crucial also offers--and suggests--PC6400 CL6.

On the one hand 6400 is faster than 5300 but on the other hand CL5 is supposed to be about as much faster than CL6.

In practical terms, in these machines, which one will be faster? Or preferable at all? Price is the same on both.

[ZaZ]

I doubt it makes a noticeable difference either way. The T61 uses PC5300 officially.

[hellosailor]

I wonder if slower ram using fewer clock cycles translates into lower power consumption?