Are you telling me you can keep GPUs cooler when they're closer together in an enclosed case
than with an open air rig in the same room using the same number of fans? If so I don't believe you.
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Another factor with cases is the type of GPU. Teslas & Quadros are designed to be placed closer together
and usually blow the hot air out the back instead out the sides into the case like most gaming cards.
Gaming cards need more space and don't work as well in cases designed for blowers.