Solid state hard drives (SSDs) aren’t just for laptops anymore—they’re making inroads into the server market. IT managers like them because they run faster and don’t use as much power, which compensates for the high price. And as far as capacity goes, IBM is testing a 4 TB SSD array. Before you switch out your hard drives, however, be aware that not all is perfect in SSD-land. Regular hard drives are still more cost-effective for systems that perform lots of non-sequential read operations or lots of write operations.