On Tue, Apr 5, 2022 at 1:40 PM Romain Dolbeau <romain%dolbeau.org@localhost> wrote: > > Le mar. 5 avr. 2022 à 20:39, Martin Husemann <martin%duskware.de@localhost> a écrit : > > On Tue, Apr 05, 2022 at 08:20:50PM +0200, Romain Dolbeau wrote: > > > I've successfully run it on a SS20 with a pair of SM100 (so 4 v7 CPUs) > > I didn't know that could work hardware wise. > > It was never officially supported by Sun (the SM100 modules were only supported in the 600MP, including pair of them, which is a nice vintage configuration), but it does work in practice - both the host and the module are sufficiently MBus Level 2 compliant to work nicely together, and for some reason (probably "didn't remove it from the know-working code in the 600MP") the PROM supports the modules... > > I tried NetBSD 9.0 on the config just to see if the software would actually work as well... and it did :-) (probably also for compatibility with the 600MP?). Performance-wise, it doesn't make any sense though, in particular as I luckily do own a pair of SM512 should I need a quad-CPU SS20. But those run way too hot for my peace of mind... (and work fine with NetBSD as well!). According to the documentation I've seen Solaris will support SMP on an sm100 rev -08 module. Unfortunately I have a -07 module so Solaris complains rather loudly about it and will only run in UP mode but NetBSD will do SMP on it. As for how useful they are, the answer is not much but also not useless either. Performance in multi-threaded work is about on par with a single sm51. Having support for these modules is nice, especially since NetBSD actually supports them better than SunOS and Solaris ever did, but it wouldn't be the end of the world if support got dropped to make newer hardware faster. Attached a dmesg to show this hardware still works in SMP on current built a few hours ago.
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