hp & lenovo and #amd & #intel #memory bus nightmares

lost a few hours yesterday to some hp & lenovo and amd & intel memory bus nightmares started when i tried swapping DDR3 / PC3 / PC3L ram between an HP and two LENOVO notebooks

• HP 255 G2 with AMD A4 memory bus FIXED at 1600Mhz
• Lenovo T410 with Core i5 memory bus ONLY works at 1333Mhz
• Lenovo Z50 with AMD FX7500 memory bus FIXED at 800Mhz

Basically the T41o refused to work with any of the other memory whereas i thought DDR3 ram was downwards compatible.

Actually just looking at my photos maybe PC3L is not downwards compatible with PC3 ?

https://www.flickr.com/photos/osde-info/29597836713/in/datetaken-public/

https://www.flickr.com/photos/osde-info/30206973295/in/datetaken-public/