This new drive is actually the professional version of the 840 series, so in a way it's a double upgrade since the 830 series didn't have a Pro version. The new drive differentiates itself from the rest of its SSD siblings by using Samsung's high-performance toggle-mode NAND flash memory, making it the direct competitor to the recently reviewed Corsair Neutron GTX.
The new Samsung 840 Pro was very fast, but it wasn't faster than the 830 series in certain tests, making it hard to justify the new drive's current cost, which is some 35 percent higher than its predecessor's. Plus the drive doesn't come with any accessories such as drive-bay converter for use with a desktop, which makes it much less of a good deal than the 830 series. In the 840 Pro's defense, it does indeed use much less power than the 830 series, or than other other SSDs I've seen for that matter.