High Sierra on Mid 2014 MBPR exhibits GPU memory leak with external displays

I'm on a late 2013 iMac 27" with a GTX 775M (2 gb) and RAM = 24 gb. Installing the latest Nvidia driver made Windowserver and Memory go totally haywire, I am pretty certain.

Typically I'm at < 10% memory pressure; post-driver update I was at 70%+ after one hour. According to Activity Monitor, at one point windowserver was using 180 GB ( ! ) of RAM, ~174 GB of which compressed. Also appeared: forty 1.03 gig "swapfiles" in /private/var/vm/ taking up 40 gigs of hard drive space (disappeared on restart). System forced logouts every few hours. It was very confusing figuring out what was causing what. All I do is browse the internet and compile TeX documents. No gaming, no computations...youtube is as graphics heavy as I get.

Solution that worked for me: I switched from Nvidia Web Driver to Default MacOS Graphics Driver in the nvidia web utility (not cuda). Now I have no problems. Slightly uglier but it's stable and non-buggy. So I will stick with this.

It is totally unacceptable to have bugs like this. Apple does not let us tweak the hardware. We are forced to use one of the three graphics cards that Apple chooses. Then we sit around not able to use the only thing they allowed us to purchase, til maybe Apple or Nvidia figure out a fix some day. (It will just happen--no PR to tell us what's going on). "We won't fix it and no you can't change it" is such a rotten message. Unfortunately the alternative is windows...

This won't work. The same hardware performs excellent after a fresh install of MacOS Sierra but exhibits the same VRAM issues with a freshly installed MacOS High Sierra with no third party apps running.

This is clearly caused by unoptimized nvidia drivers, failing to properly handle the rewritten Metal 2 WindowServer component.

This causes the discrete NVIDIA GPU to run out of VRAM, and load textures from the much slower System RAM.

The result of this are stutters and dropped frames.

I am afraid that the fix can only be supplied by Apple in form of a system update.

I think that the data does support a memory leak/incorrect memory flushing on its own. Since the GPU VRAM completely fills up over time, just by using an external display. Because of that the GPU has to run a hybrid mode, which means that it starts streaming texture data from system RAM over the PCIe bus, that is 3-5x slower and higher latency.

Therefore the computer experiences significant stutters and FPS drops due to faulty VRAM management.

Feedback - Apple Support

Same issue on the 2015 MBPR with the GT750m.
Must be some type of memory leak, this renders the machine literally unusable while connected to an external monitor.

A better tool is Activity Monitor. iStat is not the best tool for demonstrating a memory leak.

The Activity Monitor only displays System Ram usage, not VRAM (VideoRAM) usage.

This is all very interesting but the data does not support a memory leak on its own. I may see changes in memory usage on my system with no external display. Furthermore, why would this matter as a cause of the slowdown you are claiming?

I disagree.

But you complained the computer was slow. I think you meant that video was slow. Did not make that clear.

Ignore. Not relevant here.