There is a plastic around the fans on the GPU.
is it any effect on the cooling if we remove the plastic part around the fans ?
These are new cards?
I think that wouldn't affect too much. But removing it will be better.
the another question:
if we put the gpus stick together and add fans backward and in fornt on them.
Which fans will blow air to the gpus, whivh ones will be used as exaust fans ?
Most of the GPUs will throw hot air to the sides near the card's bracket, so exhaust fans must be placed on that side. Then blower fans on the other side.