Summary and Final Thoughts
In summary
Although new RAID solutions are in the works, particularly as the bandwidth offered by PCI-E is taken advantage of, the average desktop user will be mainly interested in RAID5 or RAID0+1/1+0. Falling prices of hard drives makes a large array possible for a fairly low cost making it inexpensive and easy to enjoy the benefits of a RAID system.
The Market
RAID support has found its way onto the vast majority of consumer motherboards, certainly the models aimed towards the enthusiast. These provide a good starting point for exploring RAID, but usually only support the simple versions of RAID, usually enough for the average user. Some will support more advanced forms of RAID, but will use more CPU as a result, impacting system performance.
The add-in card market for RAID cards is quite broad. There are cheap add-in cards which are essentially the chips found in onboard solutions, but in the form of a PCI device. As prices begin to rise we begin to see more RAID modes supported along with a greater number of disks. Pay enough and you can get a dedicated RAID processor to perform the necessary calculations to look after the RAID array, there are even partial hardware solutions that do some work with a dedicated processor and some with the CPU. The more you pay, the more you get in terms of performance and capabilities, it's that simple.
Trends for onboard solutions remain relatively unchanged, with the only real differences in onboard RAID solutions being the adoption of support for SATA devices. You won't see any onboard chips with full hardware RAID support, cache or other such fancy features. Not on consumer motherboards, at least.
The Players
You will find the companies that produce storage controllers also produce RAID capable versions. These include the likes of Silicon Image, Highpoint and Promise, three names you'll often find used in conjunction with onboard RAID solutions. NVIDIA's latest nForce 4 chipset has SATA RAID support built in. Add-in cards can also be found from 3ware, LSI, Adaptec, XFX and Supermicro. All offer different RAID levels, performance and channel numbers, prices reflecting that.
Final Thoughts
Some would suggest that desktop users may be most interested in RAID 0, providing improved performance without having to purchase as many disks. Of course, the biggest issue with this is that, as we've already explained, a single drive failure will result in data loss. With many consumer storage chipsets supporting RAID 1, 1+0 & 0+1, and increasingly more supporting RAID 5 (admittedly usually through software, taking up extra CPU time) and the aforementioned falling hard drive prices, a truly redundant storage system is more appealing than ever. One final point to make is that RAID is no substitute for performing backups. If something disastrous happens to your computer, you could lose your entire RAID array, so make sure you have your most precious data backed up and kept somewhere safe!
