Thursday, June 2, 2011

Parallel bars

Have computers stopped getting faster? If you looked only at the clock speeds of microprocessor chips, you might well think so. ... Instead, extra oomph has been added in recent years by packaging multiple processing engines, or “cores”, inside a single chip. Modern PCs and laptops typically have dual-core processors (such as the Intel Core i3) and some have quad-core or even six-core chips. You might expect a six-core machine to be six times faster than a machine with a single-core microprocessor. Yet for most tasks it is not. That is because nearly all software is still designed to run on a single-core chip; in other words, it is designed to do only one thing at a time. “We’re not going to have faster processors,” says Katherine Yelick, a computer scientist at the Lawrence Berkeley National Laboratory in California. Instead, making software run faster in the future will mean using parallel-programming techniques. More>