[bestboy]

I have a little doubt about the results of the Java benchmarks.

I think the JVM tests should have been executed with the same amount of heap allocated for each platform in order to get the internal dynamics/heuristics of the JVM to be comparable. IMHO all JVM tests should have been executed with -Xmx 7G (8 Gigs maximum as per the M1 MacBook Air minus a little something for the OS and the system buffers)

Still, I'm impressed with the Apple silicone.

[Macha]

Why? You cannot buy 8gb of dual channel high performance ddr4 - it's a capacity with such a small market and low expected price that manufacturers won't bother. It's only Apple that insists on $200 extra for 16gb.

[bestboy]

I'm sorry, if I wasn't making this clear enough. I'm not proposing to remove DIMMs. I'm merely suggesting to run the Java VM with the same amount of memory/heap for all the platforms. That is purely a software setting. The command-line switch to configure the heap size of a JVM is -Xmx

The reason why I'm suggesting to have the same heap size for the benchmarks is that the maximum heap size is the single most important (tuning) setting for the JVM. Based on this setting the VM sizes its internal data structures and adepts its behavior.

Also, garbage collection times are typically* dependent on the size of the heap. With most* garbage collectors collecting a 32gb heap takes longer than collecting a 8gb heap. If the workload of the benchmark allows for the heap to be used entirely, then garbage collection overhead is directly related to the heap size.

* unless a "big heap" garbage collector like ZGC or Shenandoah is used

[user5994461]

They should set both the minimum size and maximum size to 4 GB (assuming it's enough).

Heap resizing has a much bigger impact on performance than garbage collection.

[TravelPiglet]

Yeah and I didn’t see what version of Java they were using since the Apple Silicon support isn’t really mature yet.