Solid State Storage

You can configure Imperial's MegaRam-2000 and MegaRam-5000 models with a combination of Ultra160 SCSI and/or 1GBps or 2GBps Fibre Channel interfaces for use in clustered or SAN environments. You can connect the MegaRam-2000 to two redundant Fibre Channel switches or up to four servers with Ultra160 SCSI interfaces. Its 2U (3.5") rack enclosure supports up to 38.5GB of SDRAM (a configuration with two 2GBps Fibre Channel interfaces and 1GB of SDRAM sells for about $20,000). The MegaRAM-5000 supports up to 8 Fibre Channel connections or up to 16 Ultra160 SCSI interfaces, or a combination of the two. Its 5U (8.75") rack-mount chassis holds up to 51GB of SDRAM. MegaRam-5000 configured with 2GB of SDRAM and two Fibre Channel ports sells for about $48,000.

At press time, BiTMICRO was preparing to introduce the E-Disk SAN, which uses up to fifteen 26.6GB E-Disk flash-memory-based Fibre Channel disks and includes four 2GBps Fibre Channel ports. The company hadn't yet set pricing.

Should You Buy an SSD?
The lowest-priced SSD products—those you install in a system's PCI slot—are fairly inexpensive. They're suitable for server applications in which data persistence isn't critical, such as improving swap-file access for Citrix MetaFrame or Windows Terminal Servers, enabling them to support more users. These SSDs are also suitable for desktop systems of engineers, artists, or other creative employees who frequently load and work with particular files. But if these servers or workstations have more memory than you need, you might consider buying RAM disk software, which can improve I/O performance for a low price. (CENATEK sells its RAMDisk NT 4.0/2000 software for just $35, and SuperSpeed Software sells RamDisk-NT Workstation and RamDisk-2000 Professional for $89.95. RamDisk XP Professional sells for $79.95.) Considering SDRAM's relatively low cost, adding system RAM to a desktop PC so that you can use RAM disk software instead of buying an SSD might make sense. The end result won't be quite as fast an SSD because of the RAM disk's application overhead, but it still should be much faster than a mechanical hard disk. Either way, don't forget to add a small UPS (CENATEK says its RAMDisk product can save its content to a hard disk at regular intervals). For workstations and servers, SuperSpeed also offers the SuperSpeed NT and SuperSpeed 2000 RAM disk products, which it claims can write RAM disk content changes to the system's hard disks as often as several times per second. SuperSpeed NT Workstation and SuperSpeed 2000 Professional sell for $149. Single-processor versions of SuperSpeed NT and SuperSpeed 2000 sell for $399 each; two- and four-processor versions sell for $799 and $1499, respectively. The company also offers SuperSpeed 2000 Advanced Server (for Windows 2000 Advanced Server) and SuperSpeed NT Server Enterprise Edition (for Windows NT Server, Enterprise Edition—NTS/E); call SuperSpeed to get pricing for your specific configuration.

Although full-featured SSDs are much less expensive than they were a year ago, they still cost about as much as a new server. The right choice for you will depend on a careful examination of your application's I/O characteristics, your I/O growth expectations for the next few years, the number of servers affected, and whether the servers are due for replacement soon. If you need to improve the performance of just one server and you're sure that your disk subsystem is the limiting factor, test the server with 2GB of additional memory before buying an SSD. The additional RAM could make the application and OS run more efficiently, and additional memory allocated for caching purposes could provide the performance improvement you need. If time is more plentiful than money, performance tuning can also deliver significant performance improvements.

If you're using four mail servers for performance reasons and all of them are I/O-limited, sharing an SSD between two of them could deliver the needed performance with I/O bandwidth to spare, saving you time and the cost of managing superfluous servers. You can avoid buying additional servers by allocating the unused servers to other tasks. In a SAN environment with many servers, SSDs could be even more helpful, but again, careful assessment of server bottlenecks and application I/O characteristics is in order.