OCZ is now shipping Vertex 2 solid state disks with 25nm NAND flash memory but unfortunately the die shrink has a couple of serious disadvantages. An OCZ employee wrote on the company's support forum that 25nm NAND is not as robust as the previous generation in regards to the voltage needed for write and erases. While the previous generation had a program-erase cycle rating of 5,000, the SSDs with 34nm flash have a program-erase cycle of only 3,000x.
To still provide a decent life expectation, OCZ increased the amount of NAND set aside for over-provisioning by a couple of gigabytes. For instance, a 120GB disk has an unformatted capacity of 115GB, and only 107GB of this capacity is available in Windows.
Reduced life expectancy is one major disadvantage of the 25nm flash, and unfortunately a second side effect is slower performance. Dutch tech site Tweakers reports users of 25nm Vertex 2 SSDs complain about poor performance, especially when handling uncompressable data the 25nm flash seems to perform a lot poorer than its 34nm predecessor.