Regardless of your personal wealth, I doubt anyone would tell you that it makes sense to have a six-lane driveway to your home. Despite how many vehicles you own, the classic one-lane driveway probably will do just fine. A one-lane driveway certainly won’t lengthen your commute time, unless the kids leave it strewn with skateboards and bikes where a bit of weaving is required, but I digress.

Such is the logic of one of our competitors who claims that “they have 4 Gb throughout their array, and Pillar doesn’t”. Wow! Could I be your best friend? Is there any chance that if I studied under you for a few years I could amass that keen insight? The architects of our Axiom never thought of that, it is just too esoteric. If they could have only anticipated the need to have 80 jagabytes per second everywhere, they could have eliminated all bottlenecks? If only I could have drawn that pirate, I too could have been accepted into your college. (Sorry, that was mean, but gawd).

The line of reasoning leads to six-lane driveways and trees with trunks and branches that are all the same diameter. It’s stupid. I guess the reason why I get so bent out of shape about it is because it is not a service to customers to tell them something like that. Tell the truth, if you know it. What limits one architecture is not what limits another – for some it is memory bandwidth, and for others the number of RAID controllers or a pitiful amount of write cache. But don’t make up some dumb thing like “we have 4 Gb everywhere” implying that it makes you better.

Some architectures would benefit from 4, 8 or higher Gb-per-second connections to their disk. Why? Because they do all operations (RAID rebuilds and the sort) over their back-end fabric connections, like this particular competitor does. How many disks share the fabric? The back end architecture has more than a lot to do with the traffic on the interconnect – and some older architectures need lots more bandwidth than Pillar’s Axiom to accomplish the same thing.

To wit, RAID calculations, drive sparing, and rebuilds are not accomplished using the Axiom’s Fibre channel fabric connecting the Slammers to its Bricks. These drive-intensive, bandwidth-hogging, and latency-provoking operations are contained within the Brick for SATA drives, and 2 Bricks for FC drives. This great topology is what yields Pillar’s industry-leading rebuild, performance under fault, and general performance specs. This is real.

It turns out that some topologies also employ fewer, higher performance channels while others employ more numerous, lower performance channels. The issue is the aggregate bandwidth of the fabric, not bandwidth of any individual connection. The term fabric here is enlightening – you don’t tell someone that the thread size of your rope is bigger than someone else’s, therefore your rope is stronger….lest they ask, how many threads in each rope?

So while some people might find appeal to the symmetry of six lanes everywhere, or trees whose branches and trunk are all the same diameter, it is too simple-minded an assertion from which to draw conclusions.

I will confess that my driveway is wide enough to weave a bit to avoid inappropriate obstacles, but my wife still manages to park her car smack dab in the middle of everything for “just a second”.