I think a bigger issue though is high clock speeds forced on the industry for marketing reasons. Current pipelines are way way to deep, but they can never come down because that would decrease clock rates and lots of people have been trained into believing that clock speeds indicate performance. If Intel & AMD could convince the world to ignore clock rates, we'd get chips that had slightly higher throughput with much lower power consumption and slightly faster design cycles.
This was the case around the turn of the millenium, back when you had Pentium 4s that had over 30 stages in their pipelines. But those weren't really as good as AMD's less pipelined Athalon chips, and eventually Intel shifted from it's Pentium 4 lineage to the much more reasonable architecture derived from the Pentium 3, through the Pentium M, and then the Core architecture. These had around 15 pipeline stages, and despite their slower clocks the Core processors could out-preform the Pentium 4s. So the changes that you're saying could never happen did happen, and nearly a decade ago.
I think you're being downvoted because your premise is flawed; we're at an OK place with respect to pipe depth versus clock speed. As early as the Athlon line people began to realize that clock doesn't directly map to speed, and recently Intel's move to the i3, i5, i7 models really pushed consumers away from a clock-based definition of speed.
Anecdotally, I have an elderly neighbour who bought an i7 laptop, not because it was the higher number, but because her friend had told her that it was higher quality. Inadvertently, this tech-illiterate person had inferred that an i3 was somehow going to fail sooner or produce inferior results, because of the marketing Intel had performed. This kind of branding is far more powerful than Ghz nowadays, and it's a story that Intel more or less gets to make up. The only people technical enough to bother looking for a clock speed now probably understand all of the marketing jargon, more or less.
To return to the original point; Intel's marketing isn't dictated by what people want, Intel's marketing dictates what people want. They aren't trying to make higher clocked chips to convince people they're better. They have a dominant market position.
Every CPU designer I've spoken with thinks that pipelines are way too deep and clocks are way too fast, especially given memory bandwidth and latencies. So I don't see how we could be at an "OK place". Perhaps I've only spoken with ignorant CPU designers at Intel and AMD?
Obviously, technically sophisticated people understand that clock speed is not the sole determinant of performance, but a lot of people making purchasing or marketing decisions aren't that sophisticated.
I don't mean to disparage your sources, but if everyone in engineering at the two biggest desktop CPU designers thinks pipelines are too deep in current designs, we should be seeing a big change. I understand bureaucracy well enough, but I think if everyone at AMD knew how to magically improve their current design, they would have done it by now. At this point, marketing wouldn't hold them back from assuming a dominant position technically, especially not in the server space.
I've probably gotten in past my depth at this point, but it seems like the bigger complaint is memory latency and bandwidth. My understanding was that this was part of the move to on-die memory controllers and increasing levels of L2 and L3 cache.
if everyone in engineering at the two biggest desktop CPU designers thinks pipelines are too deep in current designs, we should be seeing a big change
No, not necessarily. If one company puts out a lower clocked product with equivalent performance but lower power, the other company will be able to crush them in marketing and sales. No system integrator wants to try and sell a 1GHz product to the public. No one wants to convince retailer marketers that a system clocked at half the speed of their competitors is actually just as fast.
Take a look at laptop ads and ask yourself why they mention clock speed at all. That number isn't really comparable across different product lines or generations within the same product line. But people use it as a proxy for performance, so the ads keep including it.
The graveyards are full of companies that put out better technology products than their competitors.
> No system integrator wants to try and sell a 1GHz product to the public.
AMD has pushed lots of low power parts for mobile, for integrated systems, etc. If AMD had the resources to produce a low power, slower clocked chip, why was Turion such a dog? AMD hasn't actually done very well in the mobile space historically, when they could have produced low-power Ultrabook-like designs. Hell, they could've made something like the new Chromebook and had no fans. Either there's a severe lack of vision, or this is actually much more difficult to implement with the x86 instruction set than you're lettingon.
> But people use it as a proxy for performance, so the ads keep including it.
People generally don't care about clock speeds at this point, and I don't know if they ever really did. I worked retail about 6 years ago, and customers had no clue about clock speeds. Frankly, they were mostly worried about hard drives and screen size.
> No one wants to convince retailer marketers that a system clocked at half the speed of their competitors is actually just as fast.
Retail is the tip of the iceberg. HPC is a big market, commodity servers are a huge market. Halving your power consumption in those areas would be massive, and would give AMD a real cash injection. But there's no silver bullet there. You may be slightly right, but you're massively overstating the benefits compared to the costs of implementing it.
> If AMD had the resources to produce a low power, slower clocked chip, why was Turion such a dog?
Because not even Intel can maintain two different architectures at once and stay competitive. AMD would surely go bankrupt before they could complete a major architecture re-design.
"No one wants to convince retailer marketers that a system clocked at half the speed of their competitors is actually just as fast"
They don't have to. Reviewers would shout from the rooftops that your new laptop/tablet does not feel hot when holding it and lasts significantly longer on a battery charge. Then, you market your devices by quoting the reviewers.
Even on a desktop, a cooler CPU has advantages. Put it in a smaller, quieter box, and advertise that.
I didn't downvote you, but there is research from Intel, IBM, and others showing that very deep pipelines (they disagree on the exact numbers) are indeed optimal if power isn't a concern (which it wasn't until ca. 2003). http://web.archive.org/web/20021211202017/http://systems.cs....
>they can never come down because that would decrease clock rates and lots of people have been trained into believing that clock speeds indicate performance
is a bold statement that is not likely to be true. Casual metrics of performance change, and I doubt there are many people confused as to whether they choose a 4GHz Pentium 4 over a lower clocked Core 2, much less something like a Xeon E5.
Perhaps people are not confused simply because those older processors are no longer sold. AMD certainly felt the need to fudge their frequency back in the K7 days (although megahurtz marketing may be specific to the desktop market).
