I’ve had a Qnap TS 469L for a while now, the standard 1GB physical RAM has always hovered around 80% used with a 400-500Mb Swap file in use, in order to try and speed up the responsiveness of the unit I looked into upgrading the RAM from 1GB to 3GB for the claimed 48% improvement in speed.
The best price I could find for official Qnap ram was £89. this was a bit expensive for me so I looked into alternatives. Kingston 2GB DDR3 KVR1333D3S8S9/2G appeared to have worked so I purchased a stick from eBay
The upgrade is really easy to do, just remove 3 screws, slide the cover off, pop in the new ram into the slot and turn it on. http://www.qnap.com/index.php?sn=4605 On powering up with the Kingston RAM installed all I got was the HDD lights flashing slowly red, I removed the Kingston RAM and lucky no damage had been done and every thing power back up fine.
After a bit of digging on Google if found a blog by Cyconet who had also experienced problems with the kingston RAM it turns out there are 2 different designs of ram it seems essentially that the module has a 8-chip design. The Kingston module has only 8 memory chips, but the design is a 16 chip chip both using the same part number and only the 8 chip version works with the Qnap NAS, so I ordered a Samsung M471B5773DH0-CH9
Once fitted the Samsung M471B5773DH0-CH9 worked perfectly, with a noticeable speed increase.