Thinkpads Forum

Is there any actual benefit of having PC2700 instead of PC2100 in a T40p?

Does the ram run at asynchronous speed to the FSB in T4x's ?

ie: Does the ram run at 133Mhz when PC2100 is detected, and 166Mhz is PC2700 is detected, while the FSB remains 100Mhz.


Also, if you put PC2700 in a T40, while it be recognized and run at PC2700 speeds, or will it run at PC2100?


Thanks for your help!

My 2378FVU comes with a factory PC2700 256MB. I put another stick of 1GB PC 2700, and both sticks run asynchronously to FSB as 167MHz vs 100Mhz @ a timing of 2.5-3-3-8

macmac wrote:Is there any actual benefit of having PC2700 instead of PC2100 in a T40p?

Does the ram run at asynchronous speed to the FSB in T4x's ?

ie: Does the ram run at 133Mhz when PC2100 is detected, and 166Mhz is PC2700 is detected, while the FSB remains 100Mhz.


Also, if you put PC2700 in a T40, while it be recognized and run at PC2700 speeds, or will it run at PC2100?


Thanks for your help!

Actually this was something that I was concerned about.

There was a review a while ago when Athlon had 333 MHz FSB and when they used DDR400 RAM the performance actually decreased due to asynchronous nature b/w RAm and FSB.


However, I guess that both PC2100 and PC2700 are a synchronous PC2700 will still run faster

Now I'm curious as to whether I can replace my T40p's PC2100 with PC2700 in hopes of having it run at 166Mhz.

Don't see why, at most with a bios flash, the T40's couldn't support running ram at full PC2700 speed, unless IBM has purposely prevented this from occuring.