https://bugs.kde.org/. See if there is a similar issue already in the KDE bug tracker, and if there isn't, create a new one.
If the devs can see why it's crashing, then that will help them to fix the problem.
So I'd recommend you take some time to report the issue. :)
It's late and I'm tired and probably not reading too carefully but did I just read "KDE becoming more responsive and faster"? But then gaming benchmarks? I mean, how does a gaming benchmark symbolize the responsiveness of a DE?
And the difference between 178 and 180 fps is really a significiant measure not just a measurement artifact, a summation of noise against signal?
I mean, fine if games get 2 more fps in the next version of KDE SC but is there any quantitative way to measure desktop experience?
He clearly said:
"I was also curious to see whether KWin compositing window manager improvements for KDE 4.9 had any benefit to running OpenGL full-screen games."
which I understand as "I'm aware of the fact that responsiveness does not mean faster games, but give it a try".
And got the result:
"Yes, indeed, KDE 4.9 feels much nicer! [...] there wasn't any major change in performance"
In love with KDE, here!
KDE is still far to bloated, sluggish and unstable to be considered a usable desktop environment. This latest update does nothing to address these flaws. The only sane desktops for power users and those who want to get work done are Xfce, LXDE and Cinnamon. The rest are junk.
KDE has improved remarkably since I've started using it. Great leaps in advancements in software features, greatly improved stability, and performance. As far as performance goes, I think the main areas of concern left are Kwin compositing and RAM usage. I can't wait to see those issues finally resolved. KDE's easily has the most potential among the DE's. If it's few rough edges go away, then maybe we can start geting people to come back to KDE from Gnome.