I read so many reports of Yosemite being faster that I was beginning to think I was the only one who was disappointed. I have an older machine (2010 Mac Pro to

I read so many reports of Yosemite being faster that I was beginning to think I was the only one who was disappointed. I have an older machine (2010 Mac Pro tower), but it's been upgraded to 16GB RAM and an SSD over the years. I experienced an initial degradation in UI performance with Mavericks, but after the first OS update it was as fast as ever. Yosemite comes out, and now it takes over second to switch between Safari tabs on an otherwise idle machine. I had hoped that like Mavericks, this would be resolved in the first OS update, but no such luck. I enabled the "reduce transparency" option (this was recommended to speed up the UI) but it didn't help. My mid-2012 MBr doesn't seem to suffer from this. I wonder if Apple just didn't consider video cards in older hardware. Not an unreasonable thing to do, but I'd have preferred a "sorry, this machine can't run the latest OS" message instead.