5 ms·
It would lose by a country mile, a 386 can handle about one instruction every three or four clocks, a modern desktop core can do as many as four or five ops PER
by Earw0rm 11mo ago
It would lose by a country mile, a 386 can handle about one instruction every three or four clocks, a modern desktop core can do as many as four or five ops PER clock.
It's not just the lack of branch prediction, but the primitive pipeline, no register renaming, and of course it's integer only.
A Pentium Pro with modern design size would at least be on the same playing field as today's cores. Slower by far, but recognisably doing the same job - you could see traces of the P6 design in modern Intel CPUs until quite recently, in the same way as the Super Hornet has traces of predecessors going back to the 1950s F-5. The CPUs in most battery chargers and earbuds would run rings around a 386.
- anthk 11mo agoA 386 was a beast against a 286, a 16 bit CPU. It was the minimum to run Linux with 4MB of RAM, but a 486 with and FPU destroyed it and not just in FP performance. Bear in mind that with an 386 you can barely decode an MP2 file, while with a 486 DX you can play most MP3 files at least in mono audio and maybe run Quake at the lowest settings if you own a 100 MHZ one. A 166MHZ Pentium can at least multitask a little while playing your favourite songs. Also, under Linux, a 386 would manage itself relativelly well with just terminal and SVGAlib tools (now framebuffer) and 8MB of RAM. With a 486 and 16MB of RAM, you can run X at sane speeds, even FVWM in wireframe mode to avoid window repaintings upon moving/resizing them. Next, TLS/SSL. WIth a 486 DX you can use dropbear/bearssl and even Dillo happily with just a light lag upong handhaking, good enough for TLS 1.2. Under a 486, a 30-35? year old CPU. IRC over TLS, SSH with RSA256 and the like methods, web browsing/Gemini under Dillo with TLS. Doable, I did it under VM, it worked, even email and NNTP over TLS with a LibreSSL fork against BearSSL. With a 386 in order to keep your sanity you can have plain HTTP, IRC and Gopher and plain email/Usenet. No MP3 audio, where with a 486 you could at least read news over Gopher (even today) will multitasking if you forced yourself to a terminal environment (not as hard as it sounds). If you emulate some old i440FX based PC under Qemu, switching between the 386 and 486 with -cpu flag gives the user clear results. Just set one with the Cirrus VGA and 16MB and you'll understand upong firing X. This is a great old distro to test how well 386's and 486's behaved: https://delicate-linux.net/ https://delicate-linux.net/
- iberator 11mo agoYou could run Linux with 2MB of ram with kernels before 1994 AFIK and with a.out format of binaries instead of ELF. Nowadays I think it's still doable in theory but Linux kernel have some kind of hard coded limit of 4MB (something to do with memory paging size).
- deleted 11mo ago[deleted]
- anthk 11mo agoYep but badly. Read the 4MB laptop Howto. Nowadays if I had a Pentium/k5 laptop I'd just fit a 64 MB SIMM on these and keep everything TTY/framebuffer with NetBSD and most of the unheard daemons disabled. For a 486, Delicate Linux plus a custom build queue for bearssl, libressl on top (there's a fork out there), plus brssl linked lynx, mutt, slrn, mpg123, libtls and hurl.
- iberator 10mo agoAll you need is enough memory for 'swapon' hehe Glorious days of swap space on the floppy haha
- ptspts 11mo agoWhy is ELF so much slower and/or more memory hungry than a.out on Linux?
- codebje 11mo agoRelocation information, primarily. ELF supports loading a shared library to some arbitrary memory address and fixing up references to symbols in that library accordingly, including dynamically after load time with dlopen(3). a.out did not support this. The executable format doesn't have relocation entries, which means every address in the binary was fixed at link time. Shared libraries were supported by maintaining a table of statically-assigned, non-overlapping address spaces, and at link time resolving external references to those fixed addresses. Loading is faster and simpler when all you do is copy sections into memory then jump to the start address.
- immibis 11mo agoPresumably it's much smaller. A similar but different thought experiment would also fill the 14gen-sized die with 386es running in parallel.
- atq2119 11mo agoIf you continue that thought experiment, you'd very quickly run into the issue that the way the 386 interfaces memory is hopelessly primitive and not a good match for running 1000s of cores in parallel. A large reason why out of order speculative execution is needed for performance is to deal with the memory latencies that appear in such a system.
- toast0 11mo agoThat gets you close to Larabee/Xeon Phi, although that was pentium based although amd64 and a vector engine were added and later products were Atom derived.