No, but a multi channel SSD Raid would.. expensive yes... but certainly possible. then where is your bottleneck.
Next would be I/O to the graphics card, as mentioned in the article. But in general, the bus is the next bottleneck.
However on a server where you pay by CPU having a non-CPU extension makes a lot of sense. This would be why propriety systems have GPU extensions and open source systems do not.
in short - if you need CPU in open source get get another CPU - it's cheap. If you need CPU in a closed source application you get a GPU - it doesn't work as well as a CPU but it adds performance and it doesn't incur more licensing fees.
Are you actually using crappy licensing as a reason to use alternative hardware? And when the license is open and they only restriction is technical you can use a cheaper solution, and that is a bad thing?