Toshiba’s Storage Device Division today announced two new 1.8-inch hard drives : A single-platter drive offering 120 GB of storage and a two-platter model boasting 240 GB of capacity. The devices are targeted at the digital media player, mobile gadget, digital camcorder, and ultra-mobile PC markets, setting them on a collision course with the new generation solid-state drives from the likes of Intel and Samsung.

Toshiba says its new drives feature a new mechanical design and improved firmware that increase durability and speed while reducing energy consumption by 33-percent. Thanks to fourth-generation perpendicular magnetic recording (PMR) technology, the 240 GB design (model number MK2431GAH) boasts areal density of 344 gigabits per square inch (At the risk of over-simplifying, a hard drive manufactured using PMR technology arranges the magnetic grains it uses to store data in a vertical orientation, perpendicular to the platter. On a conventional hard drive, these magnetic grains are arranged end-to-end in a longitudinal orientation).

The new drives spin their platters at 4,200 RPM to deliver media-transfer rates of 488Mb/sec and interface transfer rates of 100 MB/sec. Both drives are equipped with parallel ATA (PATA) interfaces. The 240 GB model weighs in at 59 grams (2.08 ounces), while the 120 GB model tips the scales at 48 grams (1.7 ounces).

Toshiba’s new drives deliver more capacity than solid-state drives (Intel recently announced an 80GB model, the X25-M, and plans to sample a 160 GB drive in the fourth quarter), and they’re considerably cheaper (Intel’s X25-M goes for $595 in 1,000-unit quantities). Toshiba won’t disclose OEM product pricing, but we found an older 60 GB model selling online for $275.

While solid-state drives are unquestionably more expensive than electromechanical designs, they do offer significant advantages in speed, latency, and durability, since they have no moving parts.