Linux - upgrading a server

I have a lot of perfectly legal videos.  However, they are best when compressed to h265 for the wifi and the cheap android boxes I have everywhere.  My monstrous old plasma is up in the bedroom and the kids brought home a tv for the exercise room.

My extra Linux server just holds disks, but now I want to process faster with Handbrake.  I chose an amd 3600x without graphics for speed and processors.  Handbrake can use everything.

I use the old case and power supply and I don't disturb the hard disks.  I test if it posts before I screw in the new motherboard.  Guess what?  It won't post if I don't have a graphics card.  So, back to ammie for a modest graphics card.

Then I hooked up the monitor and everything worked.  The existing linux just booted and it looked wonderful, until I put in the ethernet cable.  Dang!  I tried everything, but it wouldn't light up.  Even flashed a new bios.  But the option for the network card did not show up on the bios screen.  It was totally borked.  Returned it to ammie and waiting for a new board.  blah.

ps. I've now installed the new motherboard.  Everything works, and it is processing at full speed.

I got the MSI version of the same board, and same price.

ps.  it's 4 times faster on handbrake as my newer machine, and so 5-6 times faster than the old one.
Also handbrake may use the gpu's.