After some investigation I have now realised that this laptop wasn't designed to take 16GB of RAM. The recommended limit is 8GB:
DDR3 PC3-12800, Memory Type: DDR3 PC3-12800, DDR3 (non-ECC), Maximum Memory: 8GB, Slots: 2. Each memory slot can hold DDR3 PC3-12800 with a maximum of 4GB per slot [Not to exceed manufacturer supported memory].That isn't to say 16GB shouldn't work of course. I came to realise however, that the notebook RAM was upgraded by the reseller, and didn't come from the factory like this.
KL Computers inserted 2 x Corsair 8GB DDR3 SODIMM Memory (CMSO8GX3M1A1333C9). The RAM is a good brand and should be fine. However, I think this RAM is part of the problem, either the make, or the amount.
The laptop features has an NVIDIA GeForce GT 630M graphics with 2GB of DDR3 RAM and an Intel HD Graphics 4000. NVIDIA s Optimus real-time switching functionality lets the GeForce kick in when it's needed and kick back the rest of the time, limiting power drain and maximizing battery life.
I have had persistent problems with the laptop crashing due to this feature. I believe it is a clash between the RAM when the Optimus feature switches, primarily when down-shifting to the Intel HD Graphics 4000. Here is a similar example on YouTube, except for this user the shaking is in the horizontal axis:
The laptop got sent back to ASUS support in Germany (LetMeRepair) and they rather unhelpfully only replied that the memory that the reseller used was “non-ASUS” and “not compatible”. Their BurnInTest was successful with test RAM, and they sent me the laptop back without any fix, nor any suggestion of which RAM would be compatible.
Has anyone else seen this happen? If so, has anyone got a RAM recommendation to run 16GB of RAM in this laptop without issue? I'd love to hear from you if you have similar problems, or none at all with your 16GB RAM N56VM!
I have now got a work around to stop this happening. I just stopped the Optimus switching from occuring in the NVIDIA setting. the setting isn't entirely obvious. In Windows 7, click on the Start button, and type NVIDIA Control Panel into the All Programs search panel. Open the NVIDIA Control Panel and select 3D Settings > Manage 3D Settings from the left panel. Under the Global Settings tab on the right, switch the Preferred graphics processor to anything but Automatic. The High Performance NVIDIA Processor will of course use more battery, the Integrated Graphics less so. Set as appropriate to your environment. I think that switching the Power Management Mode from Adaptive to Prefer Maximum Performance, would do pretty much the same thing.
I hope that helps others that are having the same issue. Please feel free to leave a comment if it helped you!