Rack servers (especially 1U and 2U) by design are not optimized for use with GPUs. Main hurdles to the use of GPUs in 1 and 2U servers are that:
- GPUs require PCI x16 slots, which may not be readily present in the servers.
- Many GPUs are double-width devices so they may be blocking other slots and the x16 slots may be positioned in such way that GPU may not physically fit in
- GPUs produce a lot of heat which should be dissipated
- Actively cooled GPUs require additional power that may not be available due to the lack of connectors and depending on the position of air inlets on the GPUs the airflow may be completely blocked
Below you may watch a few videos made by hard nut Morten Hjorth about how he is trying to make GPUs installed and work in standard servers and how much Mickey Mouse experience this may involve. In some cases Morten has to use cutting tools to modify the slots and cards in order to make them work together. Not fun stuff for everyone, surely.
Installing a GTX960 in HP Proliant DL380 G9 Server
First try to push a GPU into a 2U IBM Server (2015)
Trying to squeeze an entry-level GPU with passive heatsink into IBM x3650 M3
Messing with a 3rd party riser card in IBM x3650 M3
NVIDIA GeForce graphic card install IBM x3650 M2/3 – 191
Cutting GPU to make it fit into a PCIe x8 Slot in 4U IBM Server (2016)