I am trying to upgrade my server's memory for a Dell precision 450 machine. The memory I have now (1GB in two 512 KB sticks) is DDR ECC PC2100 / CAS 2 / 266 MHz (Kingston KVR266x72c2). I want to get two sticks of 1GB each to bring me to 3GB total. It appears buying faster memory will be cheaper due to larger production.
Options I see at newegg are:
KVR266X72C25 which is CAS 2.5 and speed 266 MHz
KVR333X72C25 which is CAS 2.5 and speed 333 MHz
KVR400X72C3A which is CAS 3 and speed 400 MHz
They are all pretty much the same price ~$35 so am just looking for the one which will run best on my system.
My current memory is CAS 2, but there is none sold as CAS 2 in 266 MHz, so I wonder if CAS3 at 400 MHz is actually better latency since it is 400 MHz so 3 cycles is less than 2 cycles at 266 MHz, or is CAS 2.5 at 333 MHz better?