Le mer. 8 avr. 2020 à 11:56, Jeffrey Walton <noloa...@gmail.com> a écrit : > As old as the hardware is (circa 2000), that old PowerPC chip > outperforms some modern hardware, like Atoms, Celerons and low-end ARM > cpu's in modern gadgets.
They don't feel that fast anymore... Even a Raspberry Pi 3 will run circle around my dual-1.25 GHz G4 (not that much faster per-core, but there's 4 of them), and even more so for the single G4. And a Rpi4 is even faster per-core. And while the PATA interface is faster than the SD card of the Pi, it's not that great for I/O either. And they don't have that much memory, either. The G5 is a whole different beast (I have a quad, complete with the full complement f 16 GiB of ECC RAM, just because I can). > Testing some algorithms, like Simon-128 and Speck-128, show a need for > Altivec. For example, Integer-based Speck-128 was running at about 70 > cpb. Altivec-based Speck-128 dropped to 10 cpb even with me doing all > the 64-bit fixups. (Speck-128 runs around 2.5 cpb when the native > hardware supports 64-bit operations, like on Power8). Interesting. Maybe you could share your implementations in the Supercop benchmark? (<http://bench.cr.yp.to/supercop.html>, there's some help in "How to submit new software:"). Are you interested in just those algorithms or crypto in general? I have an AltiVec implementation of Chacha20 in there that can probably be beaten if you feel up to the challenge ;-) (unfortunately, no published results on G4 or recent one on G5 as Supercop takes forever to run, and I've already blown a power supply on my G5 so I'm reluctant to let it run for extended period of time). Cordially, -- Romain Dolbeau
