That's not a fair comparison though. I only quickly read the postgres benchmark you linked, but it looks like you stored the data on disk (!) on a machine with only 16GB of ram for the postgres benchmark, while storing the data completely in 96GB of very fast RAM for the mapd benchmark.
Unless I misread the post it's just comparing apples and oranges. If anything, the two benchmarks show that one piece of hardware (RAM) is orders of magnitude faster than the other one (SSDs). My previous comment was specifically about MySQL running on a machine where the whole dataset fits into memory.
Of course, I'm sure mapd is faster than mysql/postgres for some usecases. But the benchmark doesn't prove that in a fair comparison.
EDIT: Maybe I should add a disclaimer: I'm the founder of another open-source database product that could be considered a competitor to MapD.