[Annatar]

Okay, if that is the case, illumos and therefore SmartOS has long had stable Infiniband and MPI support and coming from Solaris is famous for his excellent scalability on very large number of processors, as well as long tradition of HPC. Why isn’t it used for HPC then?

[jabl]

Sun (you might add Oracle as well, but I think at that point whatever they could have done was too little too late) mismanagement, and Linux was/is better in many respects? It wasn't called "Slowlaris" for nothing?

And it's not like Linux is somehow famous for poor scalability, unless you're talking about the 1990'ies. Yes, back in the 1990'ies it was certainly much worse than Solaris. But for the 2.6 and subsequent releases SGI and others put a lot of work into improving it. SGI at some point sold 4096-way (might even have been 4096 cores and 8192 hw threads?) single-image supercomputers running Linux, which AFAIK is bigger than anything Solaris has been deployed on.

That being said, most HPC systems consist of 1 or 2-socket nodes connected via a network, so the kernel scaling to such extreme systems isn't that relevant in the vast majority of deployments.

[Annatar]

“Slowlaris” days were 15 years ago with Solaris 8. Meanwhile, Solaris and illumos (and therefore SmartOS) are the only operating systems I know of which provide CPU bursting. If you go put Linux and SmartOS on the same intel CPU based hardware, SmartOS is likely to beat it in performance. What might have been 15 years ago has long since (2005 with Solaris 10) not been the case.

[scentoni]

Sparc machines were not as good at number crunching as Power so Sun wasn't as well-represented in the list as IBM, and Solaris wasn't as heavily used as AIX.

[Annatar]

I’m specifically referring to running HPC on SmartOS, which runs only on intel and AMD, with full support for intel only. My question is why isn’t it used for HPC now since it provides CPU bursting, not why it wasn’t used in the past. Fair disclosure: I grew up on SGI and HPC, I know what was before.