Quick overview from the supplier:
Dell Optiplex 3090 SFF Black (Core i5-10505 3.2-4.6GHz, 8GB RAM, 256GB SSD, DVD-RW, Ubuntu)
Product Family Dell Optiplex 3090
Case Form Factor: SFF
CPU Intel Core i5-10505 (6C / 12T, 3.2-4.6GHz, 12MB)
RAM 1x 8GB DIMM DDR4-2666 (two 288-pin DIMM sockets)
HDD 256GB SSD M.2 PCIe NVMe
Card Reader yes
Optical drive 8x DVD+/-RW 9.5mm
Graphics Integrated Intel UHD Graphics 630
WLAN no
4 x USB2.0
4 x USB3.2 Gen 1
2 x DP
1Gb LAN (RJ-45)
Keyboard Dell KB216 Multimedia USB Keyboard
Mouse USB Dell MS116, Black
PSU 200 watts
Ubuntu
Maincase Black
