Processors turning into jacks of all trades

By Peter Zschunke Oct 16, 2011, 3:06 GMT

Berlin - You need a fast processor if you want a good PC. After all, it's the central processing unit (CPU) that processes orders input into the computer.

That said, many computer users are probably unaware of the technical developments that have taken place with CPUs in recent years.

Indeed, it was not so long ago that the processor and the chip set formed the core of the computer. But now, with more transistors packed into the CPU, it is taking over the jobs once performed by the chips. CPU speed frequency is, in some cases, becoming a secondary concern for people shopping for computers.

'Frequency has not been the decisive factor since 2005,' says Intel spokesman Martin Strobel. It's just one of many factors that interest users, right up there with energy consumption and the ability to perform parallel computing operations with the aid of multiple processor cores.

Today's leading CPU manufacturers play up the fact that their new processors are seamlessly integrated with the graphics processing unit. At Intel, that unit is codenamed Sandy Bridge. At AMD, it's Fusion.

Intel's adventures with Sandy Bridge were far from problem-free this year. A design problem meant that millions of chips needed to be exchanged this spring. Now that the problem has been fixed, there are now i3, i5 and i7 versions of Sandy Bridge for sale.

The i3, the starter CPU, has a dual core. Depending on the model, the i5 has either a dual core, or a quad core, with four processors. The i7 always has a quadcore.

The quadcore is a must for people who want to play the most recent computer games with the most demanding computing requirements. An i3, or just a Pentium processor, is more than enough if your computer is just for surfing or doing office work.

Keep an eye on the processor's cache size when buying a notebook. The bigger the buffer, the more data the processor can hold ready, says Strobel. Intel's i3 has a three-megabyte (MB) cache, while the i5 has six. As a rule, the i7 has eight.

When buying a processor, customers usually get the boxed version with a ventilator for cooling. Intel currently offers an i3 for 90 euros (120 dollars). A tray version without a ventilator is also available, but those are intended for computer manufacturers.

If you plan to upgrade an older PC with a new processor, first consider whether the chip set and the base are compatible. AMD's Fusion processors come with a new FM1 base. The newer Intel CPU's require an 1156 base.

If you buy a new motherboard, make sure that it is compatible with any new processor you're considering from Intel or AMD. Connections like USB 3.0 have to match up. It also has to work with components like the random access memory.

The classic three-part design for a PC's interior is slowly yielding to a two-part design. What until now has been referred to as the Northbridge and the Southbridge chip sets now consists of just one controller.

That means more of the duties are shifting to the CPU. Strobel says that's a side effect of Moore's Law, which states that every two years it should be possible to fit double the size of transistors on the same available space.

Even though other factors are coming to the fore, frequency remains a key indicator of processing power. It's just that computing power is no longer the bottleneck it once was because, these days, the processor often sits idle because it has nothing to do.

But capacities can be overwhelmed for special needs, like games with fast-moving 3D scenes. Recently the new FX processor from AMD set a new frequency rate of 8,429 gigahertz, though it did so only under extreme cooling, down to -180 degrees.

'This frequency blows every modern desktop processor away,' wrote AMD manager Simon Solotko on his company's blog, though he warned PC users that there were drawbacks.