I am setting up a home flight simulator using the Simulator X-Plane 10 and AMD graphic cards.
Xplane 10 is using Open GL for rendering
I am using two AMD graphics cards in my system the R9 380 and the R7 265.
Under Windows as a operating system both cards give me the same performance in X plane witch is OK, but i was surprised that the r9 isn't faster even it is a much newer card.
But using Linux as an operating system, both cards are not performing good(About 10 Frames lower than on Windows, and the r9 even 15 ). Of course i made these tests witch the exact same situation and conditions using an amd eyefinity group with 3 1280x1024 monitors.
As a Linux distribution i use Linux mint Debian witch is actually based on debian and as a driver for both cards the fglrx Version 15.10
Why is the Linux system performing so bad?
My system specs are:
CPU: Intel 4790k at Stock Speed 4GHz
Motherboard Gigiabyte Z97X Soc Force
Two amd graphic cards: R9 380 and R7 265
8GByte Kingston Hyper X RAM
Note there is no visible performance difference using only one of this cards in the system, even the 4790 has only 16 pci-e lanes, and with two cards every card gets only 8 Lanes
It seems that the driver performs bad on linux using open gl