Despite a poor reception for the first generation of Ultra Mobile PCs (UMPCs), manufacturers are back in force with new and updated models at the Computex trade show which opened today in Taiwan.

Leading the charge was CPU maker VIA Technologies. Although VIA does not manufacture UMPCs itself, the company was showing several products based around its CPUs. 

VIA staff demonstrated numerous handheld PCs from design partners, including at least five UMPC models from Samsung, Aigo, Amtek and iDot. The company was also showing other UMPC-style products including the OQO handheld. 

The FIC CE260, which was shown under the iDot brand, is a sub-notebook style UMPC with a full keyboard. The device will be on sale by Xmas 2007 at below $700, FIC staff said.

VIA's low power C7 CPU has achieved several significant design wins among UMPC makers during the past year.

Despite tough competition from Intel and AMD, the chip has several advantages including extremely low cost and power consumption, low temperature operation, and easy integration with VIA's support chipset.

Power consumption had been one of the biggest problems for the first generation of UMPCs, and early products were criticised for being overweight and underpowered.

Designers who increase the size of the battery risk increasing the weight of the handheld devices, but small batteries can store little power.

Despite the rash of VIA-based UMPCs appearing on the market, not all developers are happy with them.

Local manufacturer Samwell opted for a low-voltage Intel Celeron CPU for its 'semi-rugged' UMPC 657, be cause designers believe the CPU provides better performance than VIA's C7, despite a similar megahertz rating, Samwell staff said.