We received the new 48GB RAM set we ordered from Other World Computing for the Apple Xserve (roadrunner) that I installed El Capitan (OS X 10.11.5) on two weeks ago.

I installed it and this computer (which was plenty quick before) is extremely responsive now!

Below are some pics from the installation:

(http://eagle.fish.washington.edu/Arabidopsis/Pics/20160609_RAM_48GB.jpg)

(http://eagle.fish.washington.edu/Arabidopsis/Pics/20160609_xserve_cluster.jpg)

(http://eagle.fish.washington.edu/Arabidopsis/Pics/20160609_xserve_clip.jpg)

(http://eagle.fish.washington.edu/Arabidopsis/Pics/20160609_xserve_inside_old_RAM_01.jpg)

(http://eagle.fish.washington.edu/Arabidopsis/Pics/20160609_xserve_inside_new_RAM_01.jpg)

(http://eagle.fish.washington.edu/Arabidopsis/Pics/20160609_xserve_inside_new_RAM_02.jpg)

(http://eagle.fish.washington.edu/Arabidopsis/Pics/20160609_roadrunner_screen.jpg)