Samsung Electronics is showing off a new 128GB flash-based SSD (solid-state drive) at the International Consumer Electronics show in Las Vegas, one of the largest such drives shown to date.

The drive is another blow to HDDs (hard-disk drives) in laptop PCs. SSDs have several advantages over HDDs; they're lighter, more rugged, consume less power, make no noise and enable a computer to start up and load software faster than HDDs.

The only trouble is SSDs are a lot more expensive than HDDs. But that's why SSD makers, including Samsung, SanDisk and others, aim the devices at the business laptop market, where users are willing to pay more for performance and reliability.

Samsung's 128GB SSDs will be available to laptop makers in the first half of this year, director of flash marketing for Samsung, Jim Elliott, said. He declined to discuss pricing, but pointed out that the 128GB model won't carry quite the premium over HDD technology that Samsung's 64GB SDD does.

The company used a lower-cost type of flash memory chip to develop the 128GB SSD to keep costs down and put an SSD with greater storage capacity on the market, he said. The flash memory, called MLC (multi-level cell) NAND flash isn't as powerful as the SLC (single-level cell) NAND used in most SSDs, nor is it as power efficient. The main difference is that SLC NAND flash lasts 10 times longer than MLC NAND flash, 100,000 write cycles compared to 10,000 write cycles in general.

Samsung believes users won't find the difference to be much of an issue. It put a controller chip on the SSD drive that spreads information out across the 128G bytes of space on the drive to increase longevity.

"It's a trade-off," said Elliott. Write endurance is slightly lower on MLC-based SSDs, but the market is looking for larger capacity sizes without the heavy price premiums.

The 128GB SSD is available in 1.8-inch and 2.5-inch versions for notebook and desktop PCs, as well as other possible mobile devices such as ultramobile PCs.

The company used the high-speed SATA II interface on the drives to ensure speedy reading and writing. The 128GB SSDs have a sequential write speed of 70M bytes per second, but the speed highlights the difference between MLC and SLC. Samsung offers 64GB SSDs based on SLC NAND that use SATA II with sequential write speeds of 100M bytes per second and sequential read speed of 120M bytes per second.