By: Doug S (foo.delete@this.bar.bar), November 12, 2014 8:41 pm
Room: Moderated Discussions
Michael S (already5chosen.delete@this.yahoo.com) on November 12, 2014 3:02 am wrote:
> > The general impression was a strong feeling that it was optimised for marketing (i.e. high
> > GHz) and had to do some weird things to achieve the high GHz, like the double-pumped half-width
> > ALU (the fact that the double-pumped ALUs were only 16-bit wide, and double-pumping was
> > mainly used to reduce latencies for dependent instructions, is often forgotten).
>
> I don't follow. If anything, double-pumping makes achieving high GHz harder rather than easier.
> That is, unless you quote "double" GHz in you marketing materials, which Intel did not.
I think it is pretty much assumed by everyone that Intel's 10 GHz target was dependent on exposing that double pumped pipeline in a later iteration. Unless someone thinks Intel believed they were going to hit 10 GHz with a pipeline running at 20 GHz!
I'm sure if they did they'd love quoting the "7.5 GHz" or whatever versus Athlon 64's puny 3.2 GHz. Even if the Athlon 64 was faster in the real world most consumers back then were still under the impression that GHz mattered, and it would certainly be hard to ignore a difference of that magnitude. Apparently consumers still believe higher clock rate matters, as that game still seems to work when selling Android phones. Sure, the knowledgeable might know there's a difference between Exynos and Krait and so forth, but the 95% of people who don't just see a higher number and equate that to mean "faster".
Intel was forced to abandon GHz based marketing when they went back to the P6 core which had lower clock rates but higher performance when the P4 hit the power wall, which is how we ended up with these nutty model numbers. If they'd been able to clock the Core Duo line higher than the P4 line I'm sure they'd have stuck with GHz based marketing as it certainly played to their advantage with the P4. Between Intel's stranglehold on the PC makers and consumer ignorance, Intel sold a heck of a lot of slower hotter P4s for more money than faster cooler Athlon 64s.
> > The general impression was a strong feeling that it was optimised for marketing (i.e. high
> > GHz) and had to do some weird things to achieve the high GHz, like the double-pumped half-width
> > ALU (the fact that the double-pumped ALUs were only 16-bit wide, and double-pumping was
> > mainly used to reduce latencies for dependent instructions, is often forgotten).
>
> I don't follow. If anything, double-pumping makes achieving high GHz harder rather than easier.
> That is, unless you quote "double" GHz in you marketing materials, which Intel did not.
I think it is pretty much assumed by everyone that Intel's 10 GHz target was dependent on exposing that double pumped pipeline in a later iteration. Unless someone thinks Intel believed they were going to hit 10 GHz with a pipeline running at 20 GHz!
I'm sure if they did they'd love quoting the "7.5 GHz" or whatever versus Athlon 64's puny 3.2 GHz. Even if the Athlon 64 was faster in the real world most consumers back then were still under the impression that GHz mattered, and it would certainly be hard to ignore a difference of that magnitude. Apparently consumers still believe higher clock rate matters, as that game still seems to work when selling Android phones. Sure, the knowledgeable might know there's a difference between Exynos and Krait and so forth, but the 95% of people who don't just see a higher number and equate that to mean "faster".
Intel was forced to abandon GHz based marketing when they went back to the P6 core which had lower clock rates but higher performance when the P4 hit the power wall, which is how we ended up with these nutty model numbers. If they'd been able to clock the Core Duo line higher than the P4 line I'm sure they'd have stuck with GHz based marketing as it certainly played to their advantage with the P4. Between Intel's stranglehold on the PC makers and consumer ignorance, Intel sold a heck of a lot of slower hotter P4s for more money than faster cooler Athlon 64s.
