Heterogeneous cores disrupt the PCI market

The trend in CPU development is toward multiple cores on a single chip. Following Moore’s law, CPU die masks will shrink, and we will have the room to fit 8, 16, or 32 cores on a single chip.

Much of today’s software will have to be re-written to take full advantage of a large number of cores. I think the multi-core CPU will be also be a disruptive force on hardware outside of the CPU.

In the early days of the x86 processor, floating point math was very slow. It could take many clock cycles to complete a float divide, let alone square roots or trig functions. I actually worked on a video game that did all of its 3D physics and collisions as fixed point real numbers simply so they could use only the integer registers on the 386 CPU.

Slow floating point performance created the market for the separate floating point unit or coprocessor. They were sold as an optional add on.

Then Intel disrupted the market by shrinking the CPU mask image enough to fit the FPU onto the same die as the CPU. This was great for customers, but not so good for companies like Cyrix and Weitek who had been selling FPU. Then they were in the position of selling wagons wheels in Detroit when the car came on the market.

Multi-cores offer the opportunity for another disruption. The current Pentium generation architectures have offloaded several important tasks to PCI cards. These are network IO, graphics, and sound processing.

Each of these tasks are characterized by IO bound processing, lots of memory management, and device-oriented integration. The task is standardized and well defined so that specialized hardware can make the processing go faster.

In parallel processing, there is always a drop in utilization of cores as the number of cores increase because some of the task is inherently serial or requires communication and coordination.

Each additional general purpose core becomes less valuable to add to the CPU.

In the multi-core generation, there is more room on the chip to devote some of the cores to special tasks. A heterogeneous chip will have a mix of general purpose cores and specialized cores. Common IO bound tasks -- networking, sound, and graphics -- can be moved from the PCI card to the CPU.

For hardware system integrators and PC vendors, the number of subsystems they have to manage drops radically. The big win is in laptop and mobile devices. There is a dollar premium attached to smallness. Simplifying all the boards, drivers, submemory, and cards is a real economic success story.

Customers will benefit as the production cost of PC systems continues to drop radically.

Heterogeneous chips can have different mixes of cores specialized for different markets.

The losers might be the PCI card vendors who watch as the bottom end of their market gets taken away.

You can see some of the fallout already. AMD started a heterogeneous core strategy when it acquired ATI. AMD got the graphics technology that ATI had developed. Now they can roll that into future generations of heterogeneous core chips. Some of the cores will be general purpose cores, some of the cores will be built to implement Direct X 10 in hardware and support low end Vista graphics.

Intel, on the other hand, seems to be more conservative and is currently favoring more homogenous cores.

Market pressure may change that over time. It will be interesting to watch this shake out over the next few years.

A final question to ponder: What common tasks will we dedicate hardware to once we have more cores to play with?