RAM upgrade - 266 or 533mhz? PC2-4300 or 4200?

I want to upgrade the RAM in a Toshiba Satellite M70 SR3 Laptop.
SIW diagnostic software gives me the following info about the current RAM:
Capacity: 512MB; Type: DDR2 (PC2-4300); Speed: 266Mhz (DDR2 533); Supported Frequencies: 200.0 MHz, 266.7 MHz, 266.7 MHz.

The CPU is an Intel Pentium M 740, and the FSB speed is 532.0 MHz

I've been looking for replacement RAM (2x1GB), but the specs never seem to match exactly.

Is PC2-4300 the same as 4200? I read one forum post that said they're interchangeable. Often the speed on PC2-4300 or 4200 RAM is listed as 533Mhz. Some references say that a listed RAM speed of 266Mhz means an "actual" speed of 533Mhz, which is confusing. Is that what the "DDR2 533" in the specs means?

Will I be able to install 533Mhz RAM? Does the fact that the motherboard FSB is 533 Mhz matter?

Any and all replies welcome.

Thanks

Dave_t0661

 

I tend to trust crucial.com recommendations since they guarantee it will work. For your computer they recommend Pc2-5300 (if I got the model correct). I don't think there would be any compatibility issues since you want to buy two modules.

Let's wait and see if a memory person comes along to explain things.

 

You right. DDR 266Mhz means DDR2 533Mhz.

So don't get confuse about that. DDR2 always operate at twice the data rate. That's why they call it DDR2 I believe.

Your Laptop uses DDR2, So go with any of them called PC2...