IBM System x3650 M4 Product Manual page 46

NVIDIA Quadro K600 requirements:

Maximum 128 GB system memory

NVIDIA Quadro K2000 requirements:

No additional requirement

NVIDIA Quadro K4000, K5000, K6000 requirements:

Only drive backplanes 8x 2.5" HS HDD Kit (feature A1JX) or Plus 8x 2.5" HS HDD Assembly Kit

with Expander (feature A1JY) can be selected
NVIDIA Tesla K20, K40c requirements:

For models with E5-2600 v2 processors. Models with E5-2600 not supported.

Second processor required

NVIDIA Grid K2 requirements:

Second processor required

When 2 GPUs selected, only drive backplanes 8x 2.5" HS HDD Kit (feature A1JX) or Plus 8x 2.5"

HS HDD Assembly Kit with Expander (feature A1JY) can be selected
IBM System x3650 M4 46