Linux 5.15 In 2021 Is Still Improving Intel 486 Era Hardware Support

[pmorph]

Good to keep it around, with this rate modern CPUs are soon too unsafe for anything else than gaming.

[jabl]

weren't they supposed to be removing 386/486 support a couple releases ago?

386 support was dropped in 2012, AFAICS no plans to drop 486 (there are some crucial things missing in the i386 and getting rid of that allowed cleaning up some core code, but no similar benefit from dropping 486).

[lucrus]

No real point, just a pretty interesting fact. You weren't shocked by that?

Actually not, but you see, I'm just a programmer, the only things that shock me are bugs in my code...

[stormcrow]

weren't they supposed to be removing 386/486 support a couple releases ago?

The kernel people dropped 386 for lack of hardware still active able to test releases. 486s are still around in backrooms along with new hardware still being sold. I just tossed an old original Pentium motherboard, CPU, and RAM, early last year. I had no reason to keep it and no peripherals for it - and I'm out of physical space for old hardware. Some distro maintainers dropped x86 32 bit support to lower their workloads. I personally switched to BSD on an old PowerEdge P4 server that still runs quite well. I just don't use it much because of how power inefficient it is. ~90W idle P4 PowerEdge vs. ~35W idle on a Haswell Xeon Thinkserver for low traffic file server measured by my UPS.

[oiaohm]

The kernel people dropped 386 for lack of hardware still active able to test releases. 486s are still around in backrooms along with new hardware still being sold. I just tossed an old original Pentium motherboard, CPU, and RAM, early last year. I had no reason to keep it and no peripherals for it - and I'm out of physical space for old hardware. Some distro maintainers dropped x86 32 bit support to lower their workloads. I personally switched to BSD on an old PowerEdge P4 server that still runs quite well. I just don't use it much because of how power inefficient it is. ~90W idle P4 PowerEdge vs. ~35W idle on a Haswell Xeon Thinkserver for low traffic file server measured by my UPS.

There is more here .

https://github.com/MiSTer-devel/Main_MiSTer/wiki

Items like the Mister running a 486 sx 33 in a FPGA is more power effective than the original 486 by a large margin also is ultra compact. Yes this run on 5 volts 4 amps at full load with all features. So 20Watts max with the complete board with everything. Yes 486SX-33 the chip original 2.95W average 3.43W Max that before the motherboards, graphics card ....That is up over 50 watts. Of course that is without the physical space issues. The FPGA version of 486 is down right small.

So the new 486 stuff done in fpga is not the most power effective thing on earth but its not down right horrible. Also its not large space consumer so simple to slide into a testing rack somewhere(heck it small enough to shove in cases with some free space inside). Being new hardware issues are most likely software not just the hardware getting old and falling apart.

I would expect the P3 and P4 to fall out of support before 486 does due to the 486 being rebirth-ed on FPGA.

Factors that start doing in support.
1) size having enough space to store everything.
2) age as hardware ages it gets harder and harder to be sure if something is a hardware failure or a software glitch.
3) time as in developer time to do it.
4) power usage.

486 rebirth as a fpga has managed to solve most of those.

[rogerx]

An interesting thought, my old Intel 440BX 2x P3 750 Pentium w/ 1GB RAM box can now be easily replaced with a Raspberry Pi 4 board.

Much less floor space and power used; and costing a fraction less of the original cost of all the money invested in all the hardware and add-ons.

On the flip, who wants to replace something that has worked flawlessly for ~20+ years?

[oiaohm]

On the flip, who wants to replace something that has worked flawlessly for ~20+ years?

That the problem at 20 years you start seeing things like resistors and capacitors and so on starting to fail on motherboards particular cheaper ones. High grade ones start failing at around 30 years old. The hard reality is the electronics have a max functional life.

All the 386 boards are in fact past where they are reliable when the Linux kernel dropped support. 486 motherboards were in production into 2005 with new parts(include chipset) this means their 20 years comes up at 2025. Yes the 486 motherboards made after 2005 are fairly much all salvaged chip-set until the fpga replacements started appearing.

The fpga implementation is basically all new parts again. So this restarts the 20-30+ year counter for the 486 sx but as a fpga implementation.

[ravyne]

An interesting thought, my old Intel 440BX 2x P3 750 Pentium w/ 1GB RAM box can now be easily replaced with a Raspberry Pi 4 board.

Someone ran some tests awhile back and found that a RaspberryPi 4 was roughly equivalent to a Core 2 at similar clocks -- IIRC, the specific comparison was OC'ed Pi4 @ 4x2.0ghz cores ~= Core 2 duo @ 2x2.4ghz hyperthreaded cores (4 threads total, and admittedly on the lower-end of clockspeeds for core 2 arch).

This was general-use sort of performance office/web benchmark + light gaming benchmarks (comparing CPU scores). I'm sure very optimized, compute-dense workloads and/or those that benefit from larger cache still run a lot better on the Intel, but it's maybe a factor under 2x with similar clocks. GPU aside, a Pi4 isn't all that far from the PCs we were rocking just 10 years ago.