Tue. May. 06, 2008
by Joe Trickey, Storage Marketing Consultant
Despite our tendencies to latch onto hell-bent, blazingly hot, cutting edge technologies, it always makes sense to cool down a bit and take a measured look at performance innovations.
RAID controllers are on the verge of the next storage interconnect technology jump with 6Gb/s SAS. At first glance, this will double the performance of the current 3Gb/s SAS technology, which would seem like a pretty big deal to and vendors who are first to market with it will reap the rewards. Well, not so fast. It often takes leapfrog technology time to work out the kinks, often leaving early adopter customers frustrated and hot under the collar.
The reality is that 6Gb/s SAS is the next step for storage interconnects, but it's performance potential is going to depend on the design and implementation chosen. For instance, its not sufficient to only have a 6Gb/s SAS RAID controller, but also a 6Gb/s SAS Expander and 6Gb/s hard drives. This trilogy of sixes is what truly matters as none can gain any advantage without the others. So it is with technology advancements. There will be systems out there that will offer subsets of a complete, balanced solution and wary customers need to know that expected performance gains might be disappointing.
Eventually 6Gb/s SAS will have its day and the performance will make a difference in complete end to end solutions. But before you get burned, keep in mind that performance will only show significant increases when you have more than 15 hard drives attached to a server, or use very expensive Solid State Disk drives (SSD's). Servers today generally do not have that much internal storage capacity, which would require you to use externally attached storage (JBOD's) to realize the true potential of 6Gb/s SAS.