In a bid to boost sales of its mobile central processing units (CPUs), Advanced Micro Devices has quietly returned Athlon 64-branded chips into its mobile family. The new chips feature lower performance compared to AMD Turion 64 X2, but still feature two processing engines, thus, cannot be sold under AMD Sempron trade-mark.

AMD Athlon 64 X2 TK processors are specifically designed for notebooks, as they feature S1 form-factor, have thermal design power of just 31W and are produced using 65nm process technology. The chips have 512KB of secondary-level cache (256KB per core), two times less compared to currently available AMD Turion 64 X2 processors, meaning that they also feature lower performance compared to the Turion dual-core chips.

Currently it is known about two AMD’s Athlon 64 X2 TK-series processors: models TK-53 (1700MHz, 512KB L2 cache) and TK-55 (1800MHz, 512KB L2 cache), one of which is listed in AMD’s database of notebook processors and another is used in Toshiba Satellite P205D-S7438 laptop announced recently.

It was not clear at press time whether the new chips are just custom-design for select clients, or AMD is preparing a low-cost dual-core lineup for mobile computers and, perhaps, desktops and plans to use AMD Athlon 64 X2 brand-name for such chips. Next year AMD’s performance desktop processors will be sold as AMD Phenom chips, whereas performance mobile processors will continue to use AMD Turion 64 brand. The destiny of the Athlon is not completely clear.

Intel Corp. last year started to use its well-known Pentium trademark for affordable dual-core processors, whereas the relatively new Intel Core trademark is used for desktop and mobile processors with high performance.

Officials for Advanced Micro Devices did not immediately respond to an enquiry seeking for comments.