Ask HN: Hardware for data science and machine learning

What's a reasonable desktop configuration to work on these topics at home for < $2000. I guess RAM and SSD would be as much as I can afford. How about processor & graphics? I think I want to experiment with Apache Spark, Hadoop, Scipy, R. I don't want to buy laptop. The motherboard gave up on current Sager within 2 yrs. Also, I had trouble with optimus + linux in the past, so want to avoid optimus stuff.