I am not u/masklinn - but I don't know what you mean. Doesn't the runtime consume memory by setting it aside for future use? Like what else does "using" ram mean other than claiming it for a time?
In the Go number reported, the majority of the memory is the stack Go allocated for the application code anticipating processing to happen. In the Node example, the processing instead will need heap allocation.
Point being that the two numbers are different - one measures just the overhead of the runtime, the other adds the memory reserved for the app to do work.
The result then looks wasteful for Go because the benchmark.. doesn’t do anything. In a real app though, preallocating stack can often be faster than doing just-in-time heap allocation.
Not always of course! Just noting that the numbers are different things; one is runtime cost, one is runtime cost plus an optimization that assumes memory will be needed for processing after the sleep.
I agree that it would also be interesting to benchmark some actual stack or heap usage and how the runtimes handle that, but if you are running a massively parallel app you do sometimes end up scheduling jobs to sleep (or perhaps, more likely, to prepare to act but they never do and get cancelled). So I think this is a valid concern, even though it's not the only thing that amtters.
If a process allocates many pages of virtual memory, but never actually reads or writes to that memory, then it's unlikely that any physical memory backs those pages. In this sense, allocating memory is really just bookkeeping in the operating system. It's when you try to read or write that memory that the operating system will actually allocate physical memory for you.
When you first try to access the virtual memory you've allocated, there will be a page fault, causing the OS to determine if you're actually allowed to read or write to it. If you've previously allocated it, then all is good, and the OS will allocate some physical memory for you, and make your virtual memory pointers point to that physical memory. If not, well, then that's a segfault. It's not until you first try to use the memory that you actually consume RAM.