memory - Windows drivers hogging 4GB of RAM: How do I find out which driver it is?

As of late, right after boot, my Windows 8.1 (64 Bit) is using 5-6 GB RAM of the available 8 GB. I found a similar question (Windows using too much RAM, how to diagnose resource hog), which unfortunately only partly helps me. The issue I am facing is that I am failing to identify the driver that is hogging the memory.
Here is some information from my system:
What the task manager reports:

Using RamMap to get more detailed information:

So RamMap clearly shows that my drivers need more than 4GB of RAM. Using the same diagonstics described in above answer, I used poolmon for further analysis (not using the grouping by via P since my issue does not seem to be the nonpaged RAM):

So what this essentially tells me is that my most memory intense driver is using ~100MB of RAM. So this surely does not add up to 4GB.

Does anyone know what else could cause the high memory consumption?

Answer

VM, RAM Disk, SQL server, or other large RAM storage media are going to be the most likely things that regularly use this much RAM. See this discussion for more information on how these affect 'Driver Locked' memory.

I believe this can also be caused by setting your on-board video memory way too high if you are using an on-board memory card.