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Comment by jesse__

2 hours ago

> Because about 99% of the time the garbage collect is a negligible portion of your runtime

lol .. reality disagrees with you.

https://people.cs.umass.edu/~emery/pubs/gcvsmalloc.pdf#:~:te...

On page 3 they broadly conclude that if you use FIVE TIMES as much memory as your program would if managed manually, you get a 9% performance hit. If you only use DOUBLE, you get as much as a 70% hit.

Further on, there are comprehensive details on the tradeoffs between style of GC vs memory consumption vs performance.

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Moving a value from DRAM into a CPU register is an expensive operation, both in terms of latency, and power consumption. Much of the code out in the "real world" is now written in garbage collected languages. Our datacenters are extremely power hungry (as much as 2% of total power in the US is consumed by datacenters), and becoming more so every day. The conclusion here is that garbage collection is fucking expensive, in real-world terms, and we need to stop perpetuating the idea that it's not.