I've been struggling with my new 15" rMBP for a couple of weeks now. The most recent 13.04 daily builds seem pretty clean. I can manage to get most things working on it now but am struggling with the DPI issues when used in conjunction with an external monitor.

At work I use a standard monitor that is around 100-120 DPI but the rMBP is more like 240 DPI. As such when I drag a window from the MBP to the external display it goes from 'way too small' to 'way too big'.

When I try the same thing in MacOSX the window maintains it's relative size on the screen, so there must be some DPI recalculation logic going on there. Is it possible to set up something equivalent in Linux?

I've tried setting a 'compromise' DPI setting between the two but it doesn't cut it. I'm not sure if it's possible to set different DPIs on the displays, and even if I managed that, would it fix the problem?

I'm not sure if the problem lies in the driver, the X-server or the window manager. I've tried the Nouveau and Nvidia drivers and also Cinnamon, Unity and KDE.

Thanks in Advance,