Intel Says to Prepare For "Thousands of Cores"

Impy the Impiuos Imp writes to tell us that in a recent statement Intel has revealed their plans for the future and it goes well beyond the traditional processor model. Suggesting developers start thinking about tens, hundreds, or even thousand or cores, it seems Intel is pushing for a massive evolution in the way processing is handled. "Now, however, Intel is increasingly 'discussing how to scale performance to core counts that we aren't yet shipping...Dozens, hundreds, and even thousands of cores are not unusual design points around which the conversations meander,' [Anwar Ghuloum, a principal engineer with Intel's Microprocessor Technology Lab] said. He says that the more radical programming path to tap into many processing cores 'presents the "opportunity" for a major refactoring of their code base, including changes in languages, libraries, and engineering methodologies and conventions they've adhered to for (often) most of the their software's existence.'"

Comments

Memory bandwidth?

[Brietech]

If you can get a thousand cores on a chip, and you still only have enough pins for a handful (at best) of memory interfaces, doesn't memory become a HUGE bottleneck? How do these cores not get starved for data?

Disagreement about this trend

[Raul654]

At Supercomputing 2006, they had a wonderful panel where they discussed the future of computing in general, and tried to predict what computers (especially Supercomputers) would look like in 2020. Tom Sterling made what I thought was one of the most insightful observations of the panel -- most of the code out there is sequential (or nearly so) and I/O bound. So your home user checking his email, running a web browser, etc is not going to benefit much from having all that compute power. (Gamers are obviously not included in this) Thus, he predicted, processors would max out at a "relatively" low number of cores - 64 was his prediction.

Re:Disagreement about this trend

[drinkypoo]

Architectures have changed and other stuff allow a current single core of a 3.2 to easily outperform the old 3.8's but then still why don't we see new 3.8's?

The Pentium 4 is, well, it's scary. It actually has "drive" stages because it takes too long for signals to propagate between functional blocks of the processor. This is just wait time, for the signals to get where they're going.

The P4 needed a super-deep pipeline to hit those kinds of speeds as a result, and so the penalty for branch misprediction was too high.

What MAY bring us higher clock rates again, though, is processors with very high numbers of cores. You can make a processor broad, cheap, or fast, but not all three. Making the processors narrow and simple will allow them to run at high clock rates and making them highly parallel will make up for their lack of individual complexity. The benefit lies in single-tasking performance; one very non-parallelizable thread which doesn't even particularly benefit from superscalar processing could run much faster on an architecture like this than anything we have today, while more parallelizable tasks can still run faster than they do today in spite of the reduced per-core complexity due to the number of cores - if you can figure out how to do more parallelization. Of course, that is not impossible.

Re:Not Sure I'm Getting It

[cpeterso]

Now that 64-bit processors are so common, perhaps operating systems can spare some virtual address space for performance benefits.

The OPAL operating system was a University of Washington research project from the 1990s. OPAL uses a single address space for all processes. Unlike Windows 3.1, OPAL still has memory protection and every process (or "protection domain") has its own pages. The benefit of sharing a single address space is that you don't need to flush the cache (because the virtual-to-physical address mapping do not change when you context switch). Also, pointers can be shared between processes because their addresses are globally unique.

Re:Not Sure I'm Getting It

[kesuki]

yes, but if you have 1000 cores each with 64k of cache, then you start to run into problems with memory throughput when computing massively parallel data.

memory throughput has been the achilles heel of graphic processing for years now. and as we all know, splitting up a graphic screen into smaller segments is simple. so GPUs went massively parallel long before CPUS, in fact you will soon be able to get over 1000 stream processing units in a single desktop graphic card.

so, the real problem is memory technology, how can a single memory module consistently feed 1000 cores, for instance if you want to do real-time n-pass encoding of a hd video stream... while playing a FPS online, and running IM software, and a strong anti-virus suite...

I have a horrible horrible ugly feeling that you'll never be able to get a system that can reliably do all that. at the same time, just because they'll skimp on memory tech or interconnects, so you'll have most of the capabilities of a 1,000 core system wasted.