I recently purchased an external monitor - LG 24GN650-B, and I have an M1 Macbook Air. Is it possible to get 144Hz refresh rate on the external monitor when I connect my laptop to it? I am using an USB Type C Hub, and then connecting the Hub to Monitor with HDMI to HDMI cable. I will leave links of all my products below if that helps.
MacBook Air 13″, macOS 15.1
The Technical Specifications for your M1 MacBook Air do not promise support for any refresh rate over 60 Hz. You might be able to use a higher refresh rate on a 1080p monitor like this one, but I don't think that is guaranteed. But that leaves the question of why you aren't at least getting 60 Hz.
MacBook Air (M1, 2020) - Technical Specifications - Apple Support
The description of the HDMI cable ("Certified Ultra High Speed HDMI® Cable 4k 144Hz 120Hz 8k 60Hz 2k 240Hz") makes it sound like that cable should not be the problem.
Here's a link to the monitor manufacturer's site.
LG – 24" UltraGear™ (24GN650) FHD IPS 144Hz 1ms Gaming Monitor with FreeSync™
The user manual (which covers several monitors) seems to indicate that it should be able to operate at 1920x1080 @ 60 Hz, using either its HDMI input or its DisplayPort input. This monitor supports both 8-bit-per-channel color, and 10-bit-per-channel color. (With a 4K monitor, HDMI 2.0 bandwidth limitations might force a tradeoff between (60 Hz, 8-bit-per-channel color) and (30 Hz, 10-bit-per-channel color) – but for a monitor with 1080p resolution, I don't think you'd have to choose between 60 Hz and 10 bits/channel.)
The description of the Anker 332 USB-C(5-in-1) hub says that it supports streaming or mirroring HDMI to a monitor using resolutions "of up to 4K@30Hz."
Anker – Anker 332 USB-C Hub (5-in-1)
Anker Support – Anker 332 USB-C Hub (5-in-1)
Many USB-C hubs have HDMI ports that support "up to 4K@60 Hz".
The FAQ on the hub's Support page says
"What resolution does this device support?
The HDMI port supports a variety of resolutions up to 4K@30Hz and 1080p@60Hz, including 1080p, 1080i, 720p, and 480p.
Do I need to install any drivers to use this hub?
No, this hub is plug-and-play. No software/driver is required."
So I'm not sure why you're only seeing 30 Hz (instead of 60 Hz) on the monitor. Unless there's some control in the monitor menus that you need to set to select 8-bit-per-channel color, just in case this hub is assuming (incorrectly) that 10-bit-per-channel color is always a reason to cut the refresh rate back to 30 Hz.
The Technical Specifications for your M1 MacBook Air do not promise support for any refresh rate over 60 Hz. You might be able to use a higher refresh rate on a 1080p monitor like this one, but I don't think that is guaranteed. But that leaves the question of why you aren't at least getting 60 Hz.
MacBook Air (M1, 2020) - Technical Specifications - Apple Support
The description of the HDMI cable ("Certified Ultra High Speed HDMI® Cable 4k 144Hz 120Hz 8k 60Hz 2k 240Hz") makes it sound like that cable should not be the problem.
Here's a link to the monitor manufacturer's site.
LG – 24" UltraGear™ (24GN650) FHD IPS 144Hz 1ms Gaming Monitor with FreeSync™
The user manual (which covers several monitors) seems to indicate that it should be able to operate at 1920x1080 @ 60 Hz, using either its HDMI input or its DisplayPort input. This monitor supports both 8-bit-per-channel color, and 10-bit-per-channel color. (With a 4K monitor, HDMI 2.0 bandwidth limitations might force a tradeoff between (60 Hz, 8-bit-per-channel color) and (30 Hz, 10-bit-per-channel color) – but for a monitor with 1080p resolution, I don't think you'd have to choose between 60 Hz and 10 bits/channel.)
The description of the Anker 332 USB-C(5-in-1) hub says that it supports streaming or mirroring HDMI to a monitor using resolutions "of up to 4K@30Hz."
Anker – Anker 332 USB-C Hub (5-in-1)
Anker Support – Anker 332 USB-C Hub (5-in-1)
Many USB-C hubs have HDMI ports that support "up to 4K@60 Hz".
The FAQ on the hub's Support page says
"What resolution does this device support?
The HDMI port supports a variety of resolutions up to 4K@30Hz and 1080p@60Hz, including 1080p, 1080i, 720p, and 480p.
Do I need to install any drivers to use this hub?
No, this hub is plug-and-play. No software/driver is required."
So I'm not sure why you're only seeing 30 Hz (instead of 60 Hz) on the monitor. Unless there's some control in the monitor menus that you need to set to select 8-bit-per-channel color, just in case this hub is assuming (incorrectly) that 10-bit-per-channel color is always a reason to cut the refresh rate back to 30 Hz.
Thank you so much for such a well detailed response! I installed BetterDisplay on my MAC to get some information about the monitor, and this is what I got -
The pixel encoding shows (--RRRRRRRRRRGGGGGGGGGGBBBBBBBBBB), which I assume means that the hub is incorrectly setting the 10-bit-per-channel color instead of 8-bit. I have no idea how to correct this, but I will try to figure something out.
Or even 60Hz for that matter, currently I am stuck at 30Hz on my external monitor.
Getting 144Hz refresh rate on external monitor
