What would a smac be performed in?

A computer: I'm not sure if I'm taking your question TOO literally, but a SMAC stands for Sequential Multiple Analysis Computer). So the test is performed in a SMAC. The laboratory takes a blood sample and then the technician puts that sample in the SMAC, which tests your blood for either 12 or 20 chemicals in the blood depending on if its a SMAC 12 or 20. I hope this helps!