Mark Roulo (nothanks.delete@this.xxx.com) on January 9, 2015 12:59 pm wrote:
> Patrick Chase (patrickjchase.delete@this.gmail.com) on January 9, 2015 11:54 am wrote:
> > For those who don't have IEEE subs and are too lazy to search,
> > here's a direct link (found via Neal Crago's personal site):
> >
> > https://6ddba3e7c48ea938c879adbfec05061acc32bb7e.googledrive.com/host/0Bz5Zlai57wAhVUFMbjJGeG1mcnc/papers/crago_hpca13.pdf
> >
> > Figure 7 on p. 303 shows relative energy efficiency across a range of workloads. The OoO
> > flavor they evaluated does quite well, often coming second best (and typically within a
> > couple/few tens of percent) to their preferred "hybrid" approach of SMT + decoupled.
>
> In order:
>
> (1) Thank you for posting this link! I looked for non-IEEE access and failed. Now I can read the paper!
>
> (2) Fuck! I've read the paper. Note that OoO does fine, but the Rigel processor
> that they are "using" is only targeted at acceleration/throughput loads. In
> other words, OoO does well for loads outside of it's primary value area.

That's why OoO has been so successful: It offers reasonable performance with just about every sort of load imaginable.

I have to admit that I was surprised at how well OoO did in such a throughput-oriented set of benchmarks, though :-).