[Bug 48401] New: GTA IV - Framerate drop after 5 minutes of gameplay

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=48401

Bug ID: 48401
           Summary: GTA IV - Framerate drop after 5 minutes of gameplay
           Product: Wine
           Version: 4.0.3
          Hardware: x86
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: -unknown
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Hardware: Lenovo ThinkPad T410s, 1st-gen i5, NVidia NVS3100M with driver
340.107
OS: Ubuntu 18.04 / elementaryOS 5.0

When playing GTA IV under Wine, framerate is quite nicely playable: 30+fps in
wine 4.0.3, Windows 10 mode (so far, best experience).

However, framerate begins to drop abruptly after about 5 minutes of gameplay,
in the 5-10fps range, sometimes to 1-2fps. CPU+GPU begin to heat up in the high
range (90°C).

This doesn't happen as badly in other DirectX 9 games.

I've added a registry DWORD key to disable CSMT (when enabled, the described
problem begins at gameplay start, not a second later), and limited video memory
to 384Mb.

It is known, however, that GTA IV is a badly optimized game that has caused
trouble in Windows before, so I'm aware that YMMV.

Let me know how else I can help pinpointing the problem cause.