• Welcome to TechPowerUp Forums, Guest! Please check out our forum guidelines for info related to our community.

ssh -X from MAC OS to Ubuntu, error with RANDR


New Member
Nov 29, 2019
1 (0.00/day)
HI there, and congrats for the forum
After being helped by the forum a lot, I have registered to ask a question regarding the following situation:
I'm doing ssh -X from a Macbook with Catalina OS to an Ubuntu 16.04. I installed XQuartz-2.7.11 in the macbook in order to be able to handle the X11 and everything seems to be working. However, there are some programs that are not working as expected. I open a program, it starts to load and opens, but it's not responsive. Menus cannot be cliked and you cannot interact with the program. Checking the log in the terminal, I think this is due to the error: "Xlib: extension "RANDR" missing on display localhost:10.0"
In the same situation but doing ssh from another Ubuntu or from Windows + VcXsrv, the program is working perfectly, without the RANDR error. So I'm fairly certain this has to be with something on the macbook or XQuartz

Any idea on how to solve it?

Thanks for your time!


Resident Wat-man
Jan 28, 2012
11,726 (3.76/day)
Concord, NH
System Name Kratos
Processor Intel Core i7 3930k @ 4.6Ghz
Motherboard ASUS P9X79 Deluxe
Cooling Corsair H100i V2
Memory G.Skill DDR3-2133, 16gb (4x4gb) @ 9-11-10-28-108-2T 1.65v
Video Card(s) Sapphire AMD Radeon RX Vega 64
Storage 2x120Gb SATA3 SSD Raid-0, 4x1Tb RAID-5, 1x500GB, 1x512GB Samsung 960 Pro NVMe
Display(s) 1x LG 27UD69P (4k)
Case Antec 1200
Audio Device(s) Onboard Realtek® ALC898, FIIO Alpen 2 Headphone DAC + Amp
Power Supply Seasonic 1000-watt 80 PLUS Platinum
Mouse Logitech G602
Keyboard Rosewill RK-9100, Cherry MX Blues with O-rings
Software Ubuntu 20.04 LTS (Stock 5.4.0-33 kernel)
Benchmark Scores Benchmarks aren't everything.
think this is due to the error: "Xlib: extension "RANDR" missing on display localhost:10.0"
That's because libxrandr can't be found. This is probably because you're using X via xquartz and librandr just simply isn't available. I doubt that's causing your issue though. It sounds more like performance is bad which isn't entirely surprising. Instead of using
ssh -X ...
Try using this instead:
ssh -Y ...
That uses trusted X forwarding which bypasses several security extensions. That should help improve the experience. Mind you that X is not light on network resources, so if you're doing this over the internet, it's going to be slow regardless of what you're trying to do.