[TUHS] the wheel of reincarnation goes sideways

Dan Cross crossd at gmail.com
Thu Mar 9 05:52:43 AEST 2023


[bumping to COFF]

On Wed, Mar 8, 2023 at 2:05 PM ron minnich <rminnich at gmail.com> wrote:
> The wheel of reincarnation discussion got me to thinking:
>
> What I'm seeing is reversing the rotation of the wheel of reincarnation. Instead of pulling the task (e.g. graphics) from a special purpose device back into the general purpose domain, the general purpose computing domain is pushed into the special purpose device.
>
> I first saw this almost 10 years ago with a WLAN modem chip that ran linux on its 4 core cpu, all of it in a tiny package. It was faster, better, and cheaper than its traditional embedded predecessor -- because the software stack was less dedicated and single-company-created. Take Linux, add some stuff, voila! WLAN modem.
>
> Now I'm seeing it in peripheral devices that have, not one, but several independent SoCs, all running Linux, on one card. There's even been a recent remote code exploit on, ... an LCD panel.
>
> Any of these little devices, with the better part of a 1G flash and a large part of 1G DRAM, dwarfs anything Unix ever ran on. And there are more and more of them, all over the little PCB in a laptop.
>
> The evolution of platforms like laptops to becoming full distributed systems continues.
> The wheel of reincarnation spins counter clockwise -- or sideways?

About a year ago, I ran across an email written a decade or more prior
on some mainframe mailing list where someone wrote something like,
"wow! It just occurred to me that my Athlon machine is faster than the
ES/3090-600J I used in 1989!" Some guy responded angrily, rising to
the wounded honor of IBM, raving about how preposterous this was
because the mainframe could handle a thousand users logged in at one
time and there's no way this Linux box could ever do that.

I was struck by the absurdity of that; it's such a ridiculous
non-comparison. The mainframe had layers of terminal concentrators,
3270 controllers, IO controllers, etc, etc, and a software ecosystem
that made heavy use of all of that, all to keep user interaction _off_
of the actual CPU (I guess freeing that up to run COBOL programs in
batch mode...); it's not as though every time a mainframe user typed
something into a form on their terminal it interrupted the primary
CPU.

Of course, the first guy was right: the AMD machine probably _was_
more capable than a 3090 in terms of CPU performance, RAM and storage
capacity, and raw bandwidth between the CPU and IO subsystems. But the
3090 was really more like a distributed system than the Athlon box
was, with all sorts of offload capabilities. For that matter, a
thousand users probably _could_ telnet into the Athlon system. With
telnet in line mode, it'd probably even be decently responsive.

So often it seems to me like end-user systems are just continuing to
adopt "large system" techniques. Nothing new under the sun.

> I'm no longer sure the whole idea of the wheel or reincarnation is even applicable.

I often feel like the wheel has fallen onto its side, and we're
continually picking it up from the edge and flipping it over, ad
nauseum.

        - Dan C.


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