small computer with pcie expansion slots
Amazon.com: StarTech.com Thunderbolt 3 PCIe Expansion Chassis ...
And, with the speed and bandwidth support of Thunderbolt 3 and PCIe 3.0, you can enjoy many of the same port additions you would from the PCIe expansion slots of a desktop system.
PCI Express to 4 Slot PCI Expansion System - docs.rs-online.com
PCI Express to PCI Express expansion with 3 PCIe x8 Gen-3 slots. ... PCI Express to PCI Express Expansion with PCIe 3 x8 Gen-3 slots.
Lian Li Q58 Mini-ITX Case with PCIe 3.0 Riser Card (White) Q58W3
DeepCool CH160 WH Mini-ITX Computer Case, ABS+SPCC+Tempered Glass Materials, 3 Expansion Slots, x2USB3.0/Audio/1xGen2 Type-C Port, White | R-CH160-WHNGI0-G-1 model CH160 WH Computer Cases.