According to a benchmark comparison of personal computers running various implementations of Unix performed by AIM Technology, Microport’s System V/AT proved to be the best buy. Using the AIM Benchmark Suite II the company analysed four versions of Unix on an AT&T PC 6300, an IBM AT and a Summit 1000. The Santa Cruz Operation’s Xenix was tested on all three machines; Interactive System Corp’s IN/ix ran on the AT&T PC; Microport’s System V/AT and VenturCom’s Venix were used on the AT. AIM’s benchmark comprises 38 functional tests that measure the instruction speeds of the system doing specific tasks such as creating and closing files, disk copying, multiply float. AIM then sorts and weights these to form individual subsystems which are analysed to evaluate impact on overall system performance. The same tests are grouped to make up applications such as spreadsheet and compilation which are then combined to make different environments such as business and engineering. The tests showed Santa Cruz Xenix and System V/AT on the IBM and Summit doing well in a business environment. Venix did well on data collection, IN/ix performed well in general business database applications. In the engineering world Santa Cruz Xenix and Microport V/AT came out on top, but Venix did well in CAD/CAM. The report says that the AT was the best performing hardware.