By: Mark Roulo (nothanks.delete@this.xxx.com), January 9, 2015 9:13 am
Room: Moderated Discussions
coppice (coppice.delete@this.dis.org) on January 8, 2015 11:38 pm wrote:
> Mark Roulo (nothanks.delete@this.xxx.com) on January 8, 2015 6:37 pm wrote:
> > juanrga (nospam.delete@this.juanrga.com) on January 7, 2015 6:03 am wrote:
> > > I recall Aaron asking me why I believed that mixing VLIW with
> > > RA was a good idea. Funny, because we know now that
> > > Denver is an in-order VLIW+RA core that outperforms wide OoO cores such as Cyclone or Haswell.
> >
> > Have you not noticed that nVidia did not select the fastest 15W Haswell CPU they could?
> >
> > The 2955U Celeron is a 15W TDP part with no hyperthreading, a clockspeed
> > of 1.4 GHz and 2 MB of L3 cache. Turbo-boost is disabled.
> >
> > The 4650U is *also* a 15W TDP Haswell part, but it has a base frequency
> > of 1.7 GHz, 4 MB of L3 cache and will turbo to 3.3 GHz.
> >
> > Eyeballing the nVidia chart, the Denver (@ 2.5GHz?) beat
> > the 2955U by about 10% on SpecInt2000. My guess is
> > that a 4650U would beat the Denver chip by close to 2:1. When you lose by 2:1, you aren't "outperforming".
>
> The 4650U is a very expensive chip, while dual core denvers are going into tablets. Is that
> a fair comparison? I guess winning, rather than fairness, was uppermost when the comparison
> with the 2955U was made, but you have to look beyond one parameter, like watts.
Since we are addressing the *performance* of the CPU, I think that the cost of the 4650U isn't terribly relevant. For price/performance ... oh, yes! And if I thought that the manufacturing cost for the CPU portion of the 4650U was substantially higher than that of the 2955U, then, okay.
But I think that the CPU portion between these two parts is pretty much the same. Intel charges much more for the faster chip (which also has a better IGPU, I think), but only "because they can."
The 2955U isn't cheaper to manufacture because it has hyper-threading disabled. Or because turbo boosting is disabled.
juanrgo claimed very specifically: "Denver is an in-order VLIW+RA core that outperforms wide OoO cores such as Cyclone or Haswell."
The only way to get to this claim is with nVidia's choice of a slow/cheap Haswell that Intel sells cheaply for market segmentation purposes. Which is bogus if the question is "How well can Haswell perform?"
> Mark Roulo (nothanks.delete@this.xxx.com) on January 8, 2015 6:37 pm wrote:
> > juanrga (nospam.delete@this.juanrga.com) on January 7, 2015 6:03 am wrote:
> > > I recall Aaron asking me why I believed that mixing VLIW with
> > > RA was a good idea. Funny, because we know now that
> > > Denver is an in-order VLIW+RA core that outperforms wide OoO cores such as Cyclone or Haswell.
> >
> > Have you not noticed that nVidia did not select the fastest 15W Haswell CPU they could?
> >
> > The 2955U Celeron is a 15W TDP part with no hyperthreading, a clockspeed
> > of 1.4 GHz and 2 MB of L3 cache. Turbo-boost is disabled.
> >
> > The 4650U is *also* a 15W TDP Haswell part, but it has a base frequency
> > of 1.7 GHz, 4 MB of L3 cache and will turbo to 3.3 GHz.
> >
> > Eyeballing the nVidia chart, the Denver (@ 2.5GHz?) beat
> > the 2955U by about 10% on SpecInt2000. My guess is
> > that a 4650U would beat the Denver chip by close to 2:1. When you lose by 2:1, you aren't "outperforming".
>
> The 4650U is a very expensive chip, while dual core denvers are going into tablets. Is that
> a fair comparison? I guess winning, rather than fairness, was uppermost when the comparison
> with the 2955U was made, but you have to look beyond one parameter, like watts.
Since we are addressing the *performance* of the CPU, I think that the cost of the 4650U isn't terribly relevant. For price/performance ... oh, yes! And if I thought that the manufacturing cost for the CPU portion of the 4650U was substantially higher than that of the 2955U, then, okay.
But I think that the CPU portion between these two parts is pretty much the same. Intel charges much more for the faster chip (which also has a better IGPU, I think), but only "because they can."
The 2955U isn't cheaper to manufacture because it has hyper-threading disabled. Or because turbo boosting is disabled.
juanrgo claimed very specifically: "Denver is an in-order VLIW+RA core that outperforms wide OoO cores such as Cyclone or Haswell."
The only way to get to this claim is with nVidia's choice of a slow/cheap Haswell that Intel sells cheaply for market segmentation purposes. Which is bogus if the question is "How well can Haswell perform?"