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Comment by sseagull | Hacker News Reader

Not in Rust, but I've seen it with Python in scientific computing. Someone needs to do some minor matrix math, so they install numpy. Numpy isn't so bad, but if installing it via conda it pulls in MKL, which sits at 171MB right now (although I have memories of it being bigger in the past). It also pulls in intel-openmp, which is 17MB.

Just so you can multiply matrices or something.

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> Someone needs to do some minor matrix math, so they install numpy

I’m just not convinced that it’s worth the pain to avoid installing these packages.

You want speedy matrix math. Why would you install some second rate package just because it has a lighter footprint on disk? I want my dependencies rock solid so I don’t have to screw with debugging them. They’re not my core business - if (when) they don’t “just work” it’s a massive time sink.

NumPy isn’t “left pad” so this argument doesn’t seem strong to me.

Because rust is paying the price to compile everything fromch scratch on a release build, you can pay a little extra to turn on link time optimization and turn of parallelism on release builds and absolutely nothing gets compiled in that you don't use, and nothing gets repeated. Also enabling symbols to be stripped can take something with tokio, clap, serde, nalgebra (matrix stuff) and still be 2-5Mb binary. That is still huge to me because I'm old, but you can get it smaller if you want to recompile std along with your other dependencies.

MKL is usually what you want if you are doing matrix math on an Intel CPU.

A better design is to make it easy you to choose or hotswap your BLAS/LAPACK implementation. E.g. OpenBLAS for AMD.

Edit: To be clear, Netlib (the reference implementation) is almost always NOT what you want. It's designed to be readable, not optimized for modern CPUs.

I would argue that BLIS is what you want. It is proper open source and not tied to Intel platforms.

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