I’m at Intel’s software tools conference in Dubrovnik, which I have attended for the last three years, and as usual the big topic is concurrent programming and how to write code that takes advantage of the multiple cores in today’s computers.
Clearly this remains a critical subject, but in some ways the progress over these last three years has been disappointing when it comes to the PCs that most of us use. Many machines are only dual-core, which is sub-optimal for concurrent programming since there is an overhead to multi-threading programming that eats into the benefit of having two cores. Quad core is now common too, and more useful, but what about having 50 or 80 or more cores? This enables massively parallel processing of the kind that you can easily do today with general-purpose GPU programming using OpenCL or NVidia’s CUDA, but not yet on the CPU unless you have a super computer. I realise that GPU cores are not the same as CPU cores; but nevertheless they enable some spectacularly fast parallel processing.
I am interested therefore in Intel’s MIC or Many Integrated Core architecture, which combines 50 or more CPU cores on a single chip. MIC is already in preview, with hardware codenamed Knight’s Corner and a development kit called Knight’s Ferry. But when will MIC hit the mainstream for servers and workstations, and how long is it until we can have 50 cores on a commodity desktop PC? I spoke to Intel’s chief evangelist James Reinders.
Reinders first gave me some background on MIC:
“We’ve made those bold steps to dual core, quad core and we’ve got even ten core now, but if you look inside those microprocessors they have a very simple structure. All the cores are hooked together and share their connection to memory, through a shared cache usually that’s on the chip. It’s a simple computer structure, and we know from experience when you build computers with more and more processors, that eventually you go to more sophisticated connections between the cores. You don’t build a 1000-processor super computer and hook them all together with a bus to one memory.
“It’s inevitable that on a chip we need to design a more sophisticated connection. That’s what MIC’s about, that’s what the Larrabee project has always been about, a belief that we should take a bunch of x86 cores and hook them together with something more sophisticated. In this case it’s a ring, a bi-directional, 512-bit wide high performance ring, with multiple connections to memory off the chip, which gives us more bandwidth.
“That’s how I look at MIC, it’s putting a cluster-type of design on a chip.”
But what about timing?
“The first place you’ll see this is in servers and in workstations, where there’s a lot of demand for a lot of computation. In that case we’ll see that availability sometime by the end of 2012. The Intel product should be out late in that year.
“When will we see it in other devices? I think that’s a ways off. It’s a very high core count part, more than 50, it’s going to consume a fair amount of power. The same part 18 months later will probably consume half the power. So inside a decade we could see this being common on desktops, I don’t know about mobile devices, it might even make it to tablets. A decade’s a long time, it gives a lot of time for people to come up with innovative uses for it in software.
“We’ll see single core disappear everywhere.”
Incidentally, it is hard to judge how much computing power is “enough”. Although having many CPU cores may seem overkill for everyday computing, things like speech recognition or on-the-fly image processing make devices smarter at the expense of intense processing under the covers. From super computers to smartphones, if more computing capability is available history tells us that we will find ways to use it.