Brett (ggtgp.delete@this.yahoo.com) on May 9, 2013 8:26 pm wrote:
> Paul A. Clayton (paaronclayton.delete@this.gmail.com) on May 6, 2013 9:00 pm wrote:
> > With respect to Silvermont's microarchitecture, I am somewhat disappointed by the dropping of SMT. This
> > decision probably makes sense for tablets, phones, and some embedded uses, but it might be less good for
> > server workloads (though SMT is less useful in a narrow [and somewhat shallow] OoO microarchitecture).
> > (Since, as far as I know, Intel's SMT implementation does not support software setting of thread priority,
> > embedded uses that could have real-time software benefits from multithreading presumably cannot fully
> > exploit such multithreading benefits.) I admit, I am irrationally fond of multithreading.

> Even in server land actual use of SMT is a niche market limited to certain databases and >a few other tasks.

That's not true at all. If you look at server applications, the vast majority benefit from SMT. Pretty much every server chip with meaningful marketshare has some form of multithreading: Itanium, Power7, Fujitsu's SPARC, Sun's SPARC, Intel x86. The only ones missing it are AMD and IBM zseries.

> Anyone want to start a betting pool on when Intel dumps SMT for mainstream CPU's?
> The upcoming Tock, or the one after that? I guess you could also drop SMT on a Tick >update.

Sure I'll take you up on that one. I wager Intel will continue to use SMT on Skylake, Skymont and whatever comes next.

David