Toshiba is lining up the world's fasters memory chips. Testing has begun and they should be on sale in the second half the year, the company said.

The 512MB XDR (extreme data rate) DRAM chips run at 4.8GHz - about 12 times faster than typical desktop PC memory.

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 12.8Gbit/s, and this will help make them suitable for use in high-end digital TVs and PC graphics applications, a spokesman said. 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 Rambus. The chips incorporate a Rambus technology called ODR (octal data rate) signalling, which can transfer eight bits of data per clock cycle.

In addition to Toshiba, Samsung and Elpida also licence XDR technologies from Rambus, and both chip companies plan to go into mass production of 512MB XDR chips in the second half of this year, said Kim Soo-Kyoum, semi-conductor research head at IDC.

Samsung's intentions are covered here. The company intends to bring out an XDR product about fifteen times faster than DR400 later this year, with a claimed 12.8Gbit/s bandwidth. Toshiba is saying it is sampling at that rate now.

Elpida is sampling XDR memory at 6.4Gbit/s, half the Toshiba and Samsung speed. "Yes, it looks like Toshiba's is the first... and yes, it's the fastest," Kim said. "But Samsung and Elpida have similar schedules."

The 512M-bit XDR chips will not be needed for mainstream desktop computers, but the chips' ability to process large volumes of data quickly means they will be useful in very high-end workstations, network systems, and for graphics and video applications.

Adoption of XDR as a main memory in high-end computing will start during 2007. The 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.