Hi Everyone, I would appreciate much if anybody could help me regarding this question. Is it possible to safely use the dual Mac Pro with only 1 CPU installed? I found the Early 2009 Service Manual, in which it is stated that the technician could test if a given CPU works by leaving CPU B socket empty, installing the CPU into socket A and the computer should boot up. So, in this sense, for testing purposes it should definitely work, but another question whether is it okay using the Mac Pro in this configuration for a prolonged period. In principle, the X58 chipset is supporting this setup and other workstations with X58 dual socket motherboards, like HP, Dell, can be used with only 1 CPU. But I have not found any reports about someone using the Mac Pro in such a way (only one participant in these forums, who confirmed such a configuration working for a couple of minutes, but not for longer). The question has arisen as the aim is to swap in 1 high-performance hex CPU in Socket A, and possibly insert another one later in the future into socket B whenever the processing capability of a 12-core configuration will be needed. So, if anybody could confirm this working or the opposite, please let me know. Many thanks.