Libreoffice 5.1.4, 5.2.2 very slow with larger files and gtk

[Marcin Grzesiak]

On a thinkpad T460p with Intel coreI5 6300 and 16 GB RAM running fully updated LinuxMint 18 with kerne4l 4.4.0-45 the Libreoffice becomes very slow if the libreoffice-gtk, libreoffice-gtk3 or libreoffice-gnome is installed (libreoffice-gnome enforces the installation of libreoffice-gtk).

It is then much (like 4 times) slower than on thinkpad T440p with coreI5 and 8 GB ram runnning LinuxMint 17.3 with kernel with LibreOffice 5.0.4.

This happens when openning a relatively complex drawing in DRAW like a floor plan and furnishing plan for a supermarket. The file is about 800 kB on disk. It is so slow it makes the program unusable.
The problem occurrs also, although to a smaller extent, when working in WRITER on a file larger thatn 20 pages and containing 10 - 20 photos (compressed to between 200 kB and 900 kB). In both cases scrolling causes the system to use a lot of CPU power - 90% to 160% (measured by top) for several seconds, and the scrolling is very slow. A series of 3 or 4 scroll freezes the program for 5 to 30 seconds, depending on the scroll's length. As scrolling is needed often with graphics, this is a real problem.

The problem occurs with both verstion 5.1.4 from the LinuxMint repo and with the 5.2.2 downloaded and installed from the Libreoffice website.

Uninstalling the Libreoffice-gtk integration package results in ugly unthemed look, like win95, and small icons, but Libreoffice becomes REALLY FAST - somewhat faster that on the aforementioned thinpad T440p. Working is no problem.

The problem happens every time. The solution works also every time.

So obviously there seems a problem with the gtk integration, which is a pity, as I love the gtk-ish look with the sifr style.

I hope this helps, and can be resolved somehow.