Advanced Micro Devices Inc (AMD)

[Haddock]

Please state it clearly - why do you think that Intel's queue design in the P4 was for any reason other than an impressive and misleading clock rate?

I think I'm going to have trouble stating it more clearly than "They did a high MHz chip because that was the best way they knew to get high performance." Isn't that clear?

Or I could quote Haertel again. I'll paste it in, since you give the impression of not having read it first time:

Mike Haertel wrote:
> Bernd Paysan wrote:
>> Or maybe the marketing manager said "[...]So go that
>> far, and we'll always be ahead of AMD in terms of
>> GHz. GHz sells, performance is not that important."
>
> I assure you, that is *not* what happened at Intel
> with the Pentium 4.

It seems you'd rather believe your own conjectures than the reports from eye witnesses.

My claim was (and is) that when Intel cut features from the P4, they made sure they were left with a large queue design that they had to know would perform poorly with respect to the (otherwise impressive) clock rate.

When they cut features they made sure they were left with a design that still clocked high. What would you have had them done? Cut out functional units to save space, then slow down the clock to avoid confusing the consumer?

If you (at a late stage) realise that you are out of die space budget, it seems pretty obvious (to me, I'm not a chip designer) that you are not going to be able to save a lot of space by lowering your MHz target. That would mean redesigning large complex units. Instead, they reduced the number of units and fixed it up again in microcode, eg. by doing imul in the FP unit.

Rather than focussing on how the P4 performs relative to clock, try focussing on how it performs relative to what Intel could have done.

Here are the links again:

http://groups.google.com/groups?selm=slrnb5b5rf.1igv.mike%40ducky.net
http://groups.google.com/groups?selm=slrnb5c1p7.1j1d.mike%40ducky.net