Or to put it another way, without exhausting my bank account I could build from parts I can purchase today on Newegg a many CPUs 3/4ths TiB DRAM Supermicro system. Supermicro has standard boards with more memory, and has a monster you can only buy complete that'll hold 4 CPU chips and up to 6 TiB DRAM on daughter boards; I think based on some Googling that has a starting price of less than $35K.
Moore's Law is our friend. But its economics is not the friend of custom CPUs in competition with commodity ones.
Here's a 2011 book that's sort of an advanced, vs. updated version of it's 1996 predecessor: http://www.amazon.com/The-Garbage-Collection-Handbook-Manage... It covers the recent state of the art up to it's publication (e.g. Azul's Pauseless but not C4).
Does require custom hardware or kernel cooperation for speed (e.g. it needs to do batched MMU operations without clearing the TBL on each 2MB page). Looks like it's got a better read barrier than the Pauseless one; that does of course cost extra on stock hardware.
It doesn't cover parallel or real-time garbage collection (which both get far more complicated); for those, you want Jones et. al's _The Garbage Collection Handbook_ (http://www.amazon.com/The-Garbage-Collection-Handbook-Manage...) and plenty of time to explore its bibliography. (His older book is also good, but doesn't cover those topics.)
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