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Clockless Chips
iarkin writes "TechReview is running a very interesting
article about clockless chips.
Clockless, or asynchronous, chips work very much faster and consume less power than their synchronous equivalents (Intel hade some experiments on these chips back in -97, the results showed that the asynchronous chips were three times faster and consumed only half the power)."
.. otherwise people would've noticed this has been
posted before (sept 15)
Clockless chips will never take off. How are people supposed to draw incorrect conclusions about which chip is the fastest when there's no MHz/GHz rating?
"How Sun swerved to avoid Rambus"
http://www.theregister.co.uk/content/3/22279.html
More details on the CPU:
http://www.theregister.co.uk/content/3/22274.html
Sun press release:
Extends UltraSPARC III Chip Family Tree--First Use of Sun-Developed Asynchronous Logic Design in Chip's Memory Interface
At Sun Labs:
feature article
async research home page
I took the clock out of my computer with an xacto knife. I immediately noticed an infinite difference in the speed at which it ran.
I also have an asynchronous clock ever since the spring in my wristwatch snapped.
Clockless chips would result, perhaps, in the most interesting (funny?) marketing.
Intel would develop a standard way of indicating performance. Based on something their particular chips are good at. We'll say they release the Pentium Clockless 1000, Pentium Clockless 2000 and Pentium Clockless 3000.
AMD would, if trends indicate anything, market them using performance ratings. Instead of deciding performance based on the intel standard, they would have new names to indicate that their processors, in some situations, are faster than their Intel counterparts. They'd probably be called the AMD Athlon Clockless XP 1100+, and so on.
In response, Intel would start releasing worse processors, but with higher numbers. Pentium Clockless II 5000 would be their flagship.
AMD would continue making their processors in the traditional manner, but would adopt a new naming mechanism. AMD Ahtlon Clockless Performance XP Super Fantastic 6000, maybe.
Repeat ad nauseum.
-NeoTomba
The main problem with async. design is the asycnchronous part of it. In a typical computer, you have tons of parts that you use interchangably. These parts have operate at different speeds. How would two devices working at different speeds operate smoothly. Generally, this is very hard. But the thing is they can: But the devices themselves need to agree on a few things. But async. design is higly complicated because in a clockless environment you have to pretty much garauntee something like "I'll do this within 2 equivalent clock cycle." or have other types of signalling negotiation. You can't clock on a "clock" to do stuff. You have to clock on a "async" signal.
This is the problem in the large. When you go down to the chip level, there are tons of nightmares. There can be feedback loops causing race conditions that only occur at certain times. There are load problems that might increase complexity so much more than equivalent problems in a clocked design. Clocked design makes things a lot simpler and still designing a chip is extremely diffucult.
But the future I don't think is in clockless design, but "careful clock" design. For example, there are chips which are smart enough to disable sending the clock to certain part of a chip when it knows those parts will never be used. That saves a lot of power. There are chips which aim to spread the clock around carefully thus increasing the speed. And remember, almost 50% of the power in a chip is lost due to the wiring!
me.
It's not even that they "aren't good enough", it's more a matter of inertia.
Currently all the training, design tools, verification tools, etc, are geared towards solving the particular problems that come up through synchronous design. Asynchronous design avoids some of those problems completely, but has others of it's own.
Major companies are unwilling to trade a known set of problems for an unknown set.
When some of the small start-ups that are currently pursuing asynchronous chips release product and show that those problems can be practically and regularly solved then the world will sit up and take notice, but until then we're just another 'technological curiosity'.