External monitor shows double the Physical resolution under windows 10 guest

I have a mid 2012 15" MBPr with retina display running el captain (10.11) with Parallels 11.
My external display is a 27-inch DELL U2713HM Display with a physical resolution of (2560 x 1440)
My Issue is in the Windows 10 guest os shows a resolution of 5120 x 2880 for my external monitor when running full screen using all displays in full screen.
The internal display shows a Correct max of (2880 x 1800) under windows 10 guest..
I would expect the external monitor it to show a max resolution of (2560 x 1440).
Dose anyone else have this issue?
It seems wasteful to make windows render at 5120 x 2880 only to scale it back to the physical resolution of (2560 x 1440).
This seems to me to be a bug unless some one can explain why you would want to do this on purpose.

 

Hi John!
How did you managed to set 2560 x 1440 on el capitan? After installing it I can only set 1080p as the maximum resolution on my DELL U2713HM...

 

Under system preferences / displays make sure that resolution is set to default for display.
Don't know if it makes a difference but I am using a display Port connection to the DELL U2713HM and not an HDMI cable.
I am current running Golden master available to mac developers and I did a clean install.
I just worked for me with out any adjustments required.

 

Do you still have the issue?

 

Hi Maria,
I found this topic using google. We have the same sort of issues. El Capitan, Parallels 11 and Windows (8.1 or 10) on macbook Pro Retina with a Apple 27" thunderbolt screen attached via the Thunderbolt connector. The screen shows double the resolution 5120 x 2880 on the 27"screen and correct resolution on the laptop screen.
(FTY: Reverting back to parallels 10 is a workaround).

 

Guys i have the same issue on PD12 and PD13. Anybody ever found a solution?