Upgrade to Sierra on Mac Pro

[appleman]

I have an early 2009 tower model Mac Pro 2.66 GHz Quad-core Intel Xeon and need to upgrade to Sierra to run some writer software = Scrivener. My Mac Pro has an upgraded 1TB hard drive and the specs between the mid-2010 and my unit appear to be very close except for the video card. Apple indicates that my computer is limited to El Capitan 10.11.6. Is this true or can I use 10.12 Sierra?? I need Sierra according to the software mfg to operate Scrivener. I am not an experienced mac guy so I am looking for some help. Thanks,

 

[honestone]

No, you cannot run Sierra on your Mac Pro, no matter which upgrades you have added to it/implemented.

In the past, some folks tried to "hack" Mac Pros to support a newer OS that could not run on the machine, but those hacks were, at best, Rarely (if ever) successful.