Are Custom Chips An Answer to the Multicore Crisis?
Posted by Bob Warfield on March 20, 2008
Stacey Higginbotham wrote an interesting piece that made me wonder. Apparently there are lots of less than cutting edge chip fabs out there that people want to keep running. It got me to wonder. In an age where smaller features on chips translate only to more transistors, but not neccesarily faster transistors, is the ability to have more transistors as economically valuable? Particularly if we can’t put them to use? The problem is Moore’s Law these days translates to more cores, not faster clock speeds. Nearly all the software out there can’t make use of the extra cores yet, and there is a lot of discussion about how the world may have to completely retool software to make use of lots of cores. Meanwhile, Intel sails on with 6 core chips on the horizon, more to come, and not a very good idea what to do with them.
What if what separates the latest “good” fabs from older “obsolete” fabs is not longer that valuable? Maybe the value is less from ever smaller feature sizes and more from new chip types? That would shift the economics from favoring giants like Intel capable of building ever more expensive fabs to those with the IP to design more new chips on fab processes that are “good enough” for lots of interesting applications. As big as Intel is, maybe driving faster CPU’s is not the most lucrative pasttime at this point in the technology curve.
It used to be that a general purpose CPU that constantly doubled in speed every 18 months (Moore’s Law) was the place to invest. It was a truly general purpose device capable of running all sorts of software. There have been special purpose chips built too for maximum performance in various areas: graphics coprocessors and various network chips are good examples. Suppose we can make special purpose chips for almost any purpose. I once talked to a startup that had built a hardware search accelerator for example. They vanished into the Government spy world never to be heard from again, but it is intriguing.
If you could create a dirt cheap special purpose chip, what would it do? What would be the market for it?
Before the dawn of RISC there was much interest in hardware accelerators for specific languages. Lisp machines were one such. I remember reading a quote from Alan Kay that modern machines don’t run dynamic languages like Lisp and Smalltalk as much faster than the old machines like the Dorado as their newfound clockspeeds would imply they should. He hinted that radically different hardware architectures could greatly benefit such languages. I couldn’t find more on that than this quote that says the new generation is only about 50x faster than the old machines, which is a pretty poor showing indeed.
Today we have a renaissance in the interpreted and scripting languages that are descendants of languages like Lisp and Smalltalk. Languages like Ruby on Rails, Python, and PHP are very mainstream and might benefit. One wonders whether even Java might benefit. Would a chip optimized to run the virtual machines of one of these languages without regard to compatibility with the old x86 world be able to run them a lot faster? Would a chip that runs Java 10x faster than the fastest available cores from Intel be valuable at a time when Java has stopped getting faster via Moore’s Law?
It seems to me it would.