Does RAM support limit the types of RAM that can be installed even if FSB indicates otherwise?

Question

I'm thinking of upgrading the memory on my Toshiba Satellite A10 series laptop (psa10a-012nx). It currently houses PC2100 RAMs, but I'm wondering if I can improve the performance of my laptop by upgrading to PC2700 RAM. On reading the laptop's user manual, I noticed that it indicates that I should be using PC2100 DDR266 RAMs and yet the FSB is 400 Mhz. I did an analysis of the machine using the PC Wizard software and found the following information below.

NorthBridge Information :  
Architecture     : HUB 
Manufacturer     : Intel (Toshiba America Information Systems) 
Codename         : Montara 
Revision         : A1 
Bus Speed        : 99.8MHz 
FSB Frequency    : 399MHz (QDR) 
FSB max. Support : 400MHz 
RAM max. Support : DDR (266MHz)

According to the PC Wizard details, I think the machine's FSB speed is capable of handling higher speed RAM such as PC2700 DDR-333, but the machine's maximum possible support for RAM is 266MHz. I was under the impression that the FSB determines the data transfer rate of the RAM I can install, but based on the information from the user manual and PC Wizard previously mentioned, upgrading to a higer data transfer rate RAM, i.e. PC2700 DDR-333, would not give me more performance benefit over a PC2100 DDR266 RAM. Is that correct?

Answer 1

RAM clock and FSB are two different things. You can install the faster memory, but if the motherboard only supports DDR266, you will not see any benefit from it.