Sunday, August 23

Geek

Daily News Stuff 23 August 2020

Zero Bit Edition

Tech News

  • Was getting decent performance from my experimental VM under PyPy, implemented a couple more instructions, and speed absolutely cratered, dropping from 20 MIPS to 0.33 MIPS in one go.  In fact, PyPy is half the speed of regular Python now.

    It's not at all obvious why this is.  I was curious if it was a compiler bug, so I added some more instructions and performance jumped back up to 5 MIPS.

    So...  Yeah.  I might want to find a better language for this sooner rather than later.  There's an SDL2 binding for Nim, so that's an option.  Or maybe Go.  I don't want to use C, and Crystal doesn't fully support Windows yet.

    I do understand that tight loops full of indirect lookups and branches are tricky to optimise, but if the compiler is as flaky as this I won't be able to make any progress.

    Update: Gave Nim a try.  It...  Seems to work.  It looks like it's well-suited to the task, and it's reasonably quick.  It has bounds-checking enabled by default so it's not as fast as C, but that's a really nice feature to have during development.  The bounds checking and subrange types remind me a little of Ada.

    Update 2: In fact, Nim has features designed specifically for this sort of thing, like a pragma to force it to compile a case statement as a computed goto.


  • AMD released a retail version of the Ryzen 4000 APU and they're sold out already.  (WCCFTech)

    It's not clear how much stock they - they being stores in Akihabara in this case - had on hand, but whatever they had they sold on the morning of the first day of release.


  • As mentioned previously, AMD is reportedly up to something weird with their next-gen APUs.  The high-performance Cezanne chips will be Zen 3 with Vega graphics, while the low power Van Gogh chips will be Zen 2 and RDNA 2.  (WCCFTech)

    Presumably the development timelines of the CPU and GPU cores simply didn't line up.  The new Xbox and PlayStation parts are also Zen 2 with RDNA 2.

    Van Gogh will support LPDDR5 and TDPs down to 7.5W, plus a new AI core of some sort.


  • A handy guide to de-Googling your life.

    Some things are easier than others.  I'm happy with DuckDuckGo 95% of the time, but that last 5% is a sticking point.


  • Only two boxes of gluten-free chicken nuggets?  Well, since they were showing as out of stock and I was expecting zero to arrive with this delivery, that's actually an improvement.


  • Recycling is a problem.  (Wired)

    There are about $3 of recoverable raw materials in a dead solar panel.  It costs about $12 to recover those materials.  It costs about $1 to just chuck the thing in a landfill.


Disclaimer: You do the math.  I'd do it myself, but when I add that instruction the performance drops by a factor of 60.

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Apple pies are delicious. But never mind apple pies. What colour is a green orange?




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