NVIDIA usable memory 4GB instead of 6GB?

Question

I have an the following graphics card in my laptop:

GPU: NVIDIA, GeForce GTX 1060, Max-Q Design, 6 GB VRAM

I am on Linux Mint 19.1 Cinnamon 64-bit with NVIDIA drivers version 390 official:

You can see for yourself, but I know that from Dell support, I have been assured on Windows there shall be no problem, well on Linux, they don't know. Sigh ...

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I used the following command to get the whole output of dmesg (just pressed Ctrl+c afterwards):

\dmesg --human --color=always --ctime --follow > vlastimil-dmesg.log 2>&1

It is available on my hosting temporarily, will delete it probably later on: click to download.

Please check SHA-1 hash sum for your protection:

d670f6b883147ad919bb3d341d3c679493189d3f  vlastimil-dmesg.log.xz

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There, I incidentally found, I quote:

[Sat Feb  9 15:25:28 2019] [drm] Memory usable by graphics device = 4096M

What is that? Is that a fact or could it be a mistake?

I play games on this device, so it really matters to me.

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EDIT1: nvidia-smi tool screenshot

What that dmesg message means then?

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The problem has been solved by running multiple games at once with allocated memory of 5148 MiB. Still, I would like to know what that message means then.

Answer 1

The nvidia-smi monitoring tool should provide more meaningful information about the available / real memory usage under load.

Try for example:

$ watch -n 0.5 nvidia-smi

Which updates every 0.5 seconds and see if you can get above 4096 MiB threshold.

With a memory usage > 4096 MiB it should be clear that card can handle all of its 6 GiB.

Note:

The "4096M" message is from your Intel i915 graphics card. The nvidia card is initialized after that.

root@x250:/mnt/d/tmp# xzless vlastimil-dmesg.log.xz | grep drm
[Sat Feb  9 15:25:28 2019] [drm] Memory usable by graphics device = 4096M
[Sat Feb  9 15:25:28 2019] fb: switching to inteldrmfb from EFI VGA
[Sat Feb  9 15:25:28 2019] [drm] Replacing VGA console driver
[Sat Feb  9 15:25:28 2019] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[Sat Feb  9 15:25:28 2019] [drm] Driver supports precise vblank timestamp query.
[Sat Feb  9 15:25:28 2019] [drm] Finished loading DMC firmware i915/kbl_dmc_ver1_01.bin (v1.1)
[Sat Feb  9 15:25:28 2019] [drm] Initialized i915 1.6.0 20171023 for 0000:00:02.0 on minor 0
[Sat Feb  9 15:25:29 2019] fbcon: inteldrmfb (fb0) is primary device
[Sat Feb  9 15:25:29 2019] i915 0000:00:02.0: fb0: inteldrmfb frame buffer device
[Sat Feb  9 15:25:29 2019] [drm] RC6 on
[Sat Feb  9 15:25:37 2019] [drm] [nvidia-drm] [GPU ID 0x00000100] Loading driver
[Sat Feb  9 15:25:37 2019] [drm] Initialized nvidia-drm 0.0.0 20160202 for 0000:01:00.0 on minor 1