I have just upgraded my PC. It was an old intel Q8400 with an nvidia graphics card. I changed the CPU (now an i3-6300) + Motherboard, and ditched the graphics card (want to use intel's graphics card that comes with the CPU).
Now, however, I get the message that Cinnamon is running without video hardware acceleration, and everything on screen is "laggy". I also have a dual monitor setup and when I go to system settings -> display I only see one display named as "laptop". Display detection does not work, and they are mirrored. Logically it has to do with the drivers.
Based on this thread I should look for a related xorg.conf file, but there seems to be none related (below are my xorg.conf file search results)
/usr/share/X11/xorg.conf.d /usr/share/X11/xorg.conf.d/10-evdev.conf /usr/share/X11/xorg.conf.d/10-quirks.conf /usr/share/X11/xorg.conf.d/11-evdev-quirks.conf /usr/share/X11/xorg.conf.d/11-evdev-trackpoint.conf /usr/share/X11/xorg.conf.d/50-synaptics.conf /usr/share/X11/xorg.conf.d/50-vmmouse.conf /usr/share/X11/xorg.conf.d/50-wacom.conf /usr/share/X11/xorg.conf.d/51-synaptics-quirks.conf /usr/share/man/man5/xorg.conf.5.gz /usr/share/man/man5/xorg.conf.d.5.gz
System info based on
inxi (seems like Intel drivers are actually being used):
$ inxi -b System: Host: HomePC Kernel: 3.16.0-38-generic x86_64 (64 bit) Desktop: Cinnamon 2.6.13 Distro: Linux Mint 17.2 Rafaela Machine: Mobo: ASUSTeK model: B150M-C version: Rev X.0x serial: 151055956202383 Bios: American Megatrends version: 0402 date: 09/25/2015 CPU: Dual core Intel Core i3-6300 CPU (-HT-MCP-) clocked at 760.00 MHz Graphics: Card: Intel Device 1912 X.org: 1.15.1 drivers: fbdev,intel (unloaded: vesa) tty size: 80x24 Advanced Data: N/A for root Network: Card: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller driver: r8169 Drives: HDD Total Size: 256.1GB (6.7% used) Info: Processes: 215 Uptime: 1 min Memory: 1472.4/15928.1MB Client: Shell (bash) inxi: 1.9.17