… when hardware acceleration is switched on. Yeah, that’s weird, isn’t it? I’ve seen it several times on different machines though, including that one time when WPF was just killing my machine and I hunted around for the reason for two hours before remembering… Part of the reason for this post. So, if WPF is running oddly slowly in your VM, try switching off the hardware acceleration setting. In VMWare Fusion on the Mac, you need to click on the Display icon in the settings window to find the Accelerate 3D Graphics setting. I know that other VMWare versions have the setting as well, but I’m not sure where exactly it is. Every now and then I give this another try, because it seems so weird and I think perhaps they’re going to fix it one day. But as of today, this behavior is what it is on both my MacBook and my Mac Pro.