For Zwift I am using either of these: MacBook Pro (Mid 2012), MacMini (Late 2012) and ATV. The only one that gives me proper shadows (and I assume overall better graphics) is the MacBook. From the other two I just get a grey blob under the bikes.
Not sure about ATV specs but the two Macs have identical graphics card specs (Intel HD Graphics 4000 1536 MB). The MacBook has a a better processor (2.3 GHz Quad-Core Intel Core i7 vs. 2.3 GHz Intel Core i7) but less RAM (8 GB 1600 MHz DDR3 vs. 16 GB 1600 MHz DDR3).
Why can I not get shadows on the MacMini? Is it because of the processor or is it something in the settings that I have missed?