the motherboard like most motherboards would use a non-free bios
if you want a free bios theirs a list of supported motherboards here:
http://www.libreboot.org/docs/hcl/index.html#supported_list
but they will be older and wont support a i7 at least yet
if you don’t mind a non-free bios
the motherboard wont have any other freedom problems
the things you need to think about are add-on devices
like graphics cards wifi cards etc
for graphics
if you get a intel's board the integrated graphics it will work perfectly but
if you want a modern graphics card
here is one that works well with free software:
https://www.thinkpenguin.com/gnu-linux/geforce-8400gs-1gb-pci-express-20-video-card-gnulinux-full-low-profile-brackets
but of course you dont rely need a gpu
i ran 0ad on a computer fine at low setting
4gb ram ddr3
intel integrated graphics
2.13ghz quad core cpu i3
80mbps HDD
and if you have a more powerful processor
e.g an i7 and a decent HDD or ideally a super fast SSD
then like i do you can run just about any graphical program
at very high settings
having fast ram helps with this though
as the system ram is used for video memory
so the faster the system ram is the faster
your pc can process graphics
for wifi cards (Ethernet will work fine):
https://www.thinkpenguin.com/catalog/wireless-networking-gnulinux
https://h-node.org/wifi/catalogue/en
for sound cards this one works well
the fact that its usb 2.0 dose not matter
it gives very good sound
https://www.thinkpenguin.com/gnu-linux/penguin-usb-20-external-usb-sound-card-gnu-linux
also if your going to build a pc and have the money
i highly recommend getting a cheaper 128gb or 64gb ssd
for storing your programs and os
and a second bigger 500gb or 1tb HDD
for storing music video etc
you can make trisquel mount you HDD
from startup by editing this file:
/etc/fstab:
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
#
# / was on /dev/sdb1 during installation
UUID=09c679cf-a27f-4e71-9765-0b73f1784154 / ext4
errors=remount-ro 0 1
# swap was on /dev/sdb5 during installation
UUID=da998e20-f8fe-4718-9388-9dda8ce8c61f none swap sw
0 0
/dev/sr0 /media/cdrom0 udf,iso9660 user,noauto 0 0
/dev/sda /media/HDD\0401tb ext4#this is my harddrive mounted from /dev/sda as
/media/HDD\0401tb with its file system ext4
if you need help editing this file then feel free to
ask on the forums its not too hard