Thinkpads Forum

I want to add 8GB memory to my W520. I found a good deal on the Kingston KAS-N3CL/8G 8GB 1X8GB DDR3 1600MHz. I know it is 1600Mhz and 1.35v. Will this work in my current configuration? Can I use either 1x8GB or 2x4GB?

Processor Intel Core i7-2720QM (Quad-Core) Processor
System graphics NVIDIA Quadro 1000M Optimus Graphics technology (2GB)
Total memory 2x4 GB PC3-10600 DDR3 SDRAM 1333MHz SODIMM Memory (Lenovo)

It should. I have W520 with 32 GB RAM in it, namely 4 sticks of Corsair Dominator I think, 8GB each. Hope I was somewhat helpful

Installed the 8GB memory and system boots up fine. Windows 7 System reports 16GB memory installed but 7GB available. Why is that?

It means that the new (1600MHz) 8GB is NOT recognized.
It's either faulty, or the wrong speed.
Thinkpads can be very picky about proper RAM-speed, and yours only requires 1333MHz (but might work with certain faster ones).

Could be related to the BIOS update that throttled the memory speed (although it should just slow down to 1333).
Pretty sure it isn't the voltage; 1.35v memory is normally able to run at 1.5v as well. I have DDR3L running in my X220.
Most likely if the memory or slot isn't faulty the problem is that the module doesn't have the required timings when running at the reduced speed.
Also note this is probably equivalent to Kingston's "ValueRam" which is not well-regarded. I have Kingston HyperX in my W520 (2x8GB) running at 1600 with BIOS 1.36 .