I started tracking a bunch of passmark settings on my computers as home.
Of course my personal rig is the fastest, but I was surprised which machines were second.
Also my machine was a clear #1 in all categories, over all passmark, cpumark, memory, 2d video and 3d video, but second place the categories were all over the place. I am also surprised that the dell optiplexes had better 2D performance then some of the other rigs meant for gaming.
One common thing with the optiplexes (and mine) is that we all had 1080P monitors, I had my son switch out his monitor and it seems to fix blanking issues. Granted I gave him my old rig.
My youngest son also helped me build a budget rig, it is a nice little cheap machine. Maybe I can get a small enough case to fit behind the TV.