Today I installed Ubuntu Server 24.04.2 LTS from the ubuntu-24.04.2-live-server-amd64.iso on a small PC that now sits under my desk.

The monitor is a Dell U2723QX (27", 3840×2160).

After first boot the console characters were barely 1 mm high—fine for 30 cm viewing distance, not for normal use.

1. First sight

Bash
login: _

Each glyph was a tiny pixel cluster at 3840×2160.
I could not read the LUKS prompt without standing up.

2. Quick test with fbset

Bash
sudo apt update && sudo apt install fbset
fbset -xres 2048 -yres 1536

Worked immediately; after reboot the kernel re-probed EDID and jumped back to 4 K.
Not persistent.

3. Reboot into GRUB

  • Power-cycle, hold Shift.
  • Press c for the GRUB command line.
Bash
grub> vbeinfo

Output (excerpt):

Bash
0x160  2048 x 1536 x 32  (hex 0x160 = dec 352)

This is the largest 4:3 VESA mode the Dell firmware advertises.

4. Apply the mode permanently

Bash
sudo vim /etc/default/grub

Changed:

Bash
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash vga=352"

Save, then:

Bash
sudo update-grub
sudo reboot

5. Result

  • Console now starts at 2048×1536.
  • Characters are ~4 mm tall—comfortable at arm’s length.
  • Mode survives every kernel update; no extra packages required.

Done.