Toshiba has begun sampling computer memory chips with the world's fastest data rate and will start mass production of the chips in the second half of this year.

The 512Mb XDR (extreme data rate) DRAM (dynamic random access memory) chips run at a speed of 4.8GHz, which is about 12 times faster than that of the memory typically found in today's desktop PCs, according to Junichi Nagaki, a Toshiba spokesman.

DRAM is the main type of memory used in PCs and servers. The faster the memory, the more smoothly computers tend to work and faster memory helps games machines produce better graphics.

Working at the 4.8GHz speed, the chips deliver a bandwidth of 12.8GB per second, and this will help make them suitable for use in high-end digital TVs and PC graphics applications, according to Nagaki.

If more voltage is used, the chips can work at a peak operating speed of 6.4GHz, according to Toshiba.

XDR is the name of a memory technology developed by US-based Rambus. The chips also incorporate a Rambus technology called ODR (octal data rate) signalling, which can transfer eight bits of data per clock cycle.

XDR technology will find a home in one potentially popular product: Sony is planning to use four 256Mb XDR chips in the upcoming PlayStation 3 games console.