Multi-core chips deliver faster operations but could double per-processor OS charges

Intel's move to put two processors on the same chip may give Linux a boost

Open source supporters should be rubbing their hands with glee, following Intel's decision to take the multi-core route to increased processor performance. It is a decision that must be very bad news for companies such as IBM and Oracle. In the long term, it could also put a cap on Microsoft's earnings.

Processor performance has been more or less predictable for the past two decades. The main driver has been the increase in the speed of Intel chips from 4.7MHz to 4GHz (which needs a little overclocking). Everyone knows that megahertz on one processor are not identical to megahertz on a different design, but still, no one wants to trade a 2GHz PowerPC chip for a 1GHz version.

Things changed at the Intel Developer Forum in San Francisco this month, when Intel followed AMD and others in taking a new direction. Instead of making one processor run faster, it said it would put two processors on the same chip. This almost doubles the power of a Pentium without creating the heat problems of increasing the clock speed to 8GHz.

This was not a surprise, for two reasons. First, Intel had already started down this route with what it calls "hyperthreading": a single HT Pentium already looks like two chips to the operating system. Second, Intel had already abandoned the old Pentium design in favour of the clever Banias design developed at its lab in Israel.

Banias chips, used in the Centrino mobile platform, already do more work at lower clock speeds. This puts Intel in a position where it will have to sell new 1.5GHz-2GHz processors against its own 3GHz-4GHz designs.

The problem is that software suppliers such as IBM and Oracle charge per processor. Swapping a single core chip for a dual-core version will therefore double the cost of your software.

Oracle argues that this is fair because one multi-core chip will often replace a two-chip design (and so on, pro rata). But for customers, it is clearly not a sustainable pricing model.

Microsoft does not have such an urgent problem, because it already allows software to run on two processors as standard. However, it will still have to find a pricing model that makes sense for PCs with one or two processors, each with two or more hyperthreading cores. It clearly will not be able to charge four- or eight-times the price it charges for running the same software on one Pentium.

But there are suppliers that will be able to exploit multi-core chips without these pricing problems: the ones supplying open source GNU/Linux. They don't have to care how many copies of the operating system you might be running, since it is free. They can charge per server and per desktop PC for support, which is what users want.

Jack Schofield is technology editor at the Guardian

Read more on Operating systems software