Marking Intel's first appearance in the enterprise storage array solid state disk (SSD) market, Pillar Data is launching SSD enclosures for its Axiom arrays in June. Axiom is Pillar's array line with different levels of storage service available from a application-aware quality of service (QoS) system. The arrays use storage …
Smaller and smaller steps...
Greater and greater leaps...
And well-packed. Now we're getting somewhere...
(Paris, cos she's well-packed and likes embracing things, although she'd rather be coming somewhere...)
Intel Not Equal STEC
There is no comparison between the Intel and STEC drives - X25 IOPS much lower, single interface on X25 vs 2 IO interface on STEC, no cache or power loss cache de-staging mechanism.
I think Intel sums it up when they say in the data sheet: "The Intel X25-E SATA SSD primarily targets high-end workstations, desktops, gaming and various server/storage applications."
STEC are clearly the market leader in Enterprise Flash Drives - You get what you pay for.
Latency and random IO is the key
He's right, it's the random IO rate and latency that are the key benefits of SSDs. Bandwidth is easy, you can always buy more width. IO rates you can increase by buying more mechs. But no amount of purchasing mechanical disk drives is ever going to effect the latency times for data access. Apart from massively over provisioning storage so that you only make tiny head movements. But even if you get to the point where you have so many disk drives that you are only using 1 track on each of them you still have a 2ms average latency time on a 15K rpm disk. Using twin head towers you could get down to 1ms.
With SSDs you are in a totally different ball park.
Indeed the STEC will greatly outperform the Intel, but there are a couple of important points. Firstly, there is the not insignificant one on costs - it's debatable just how many real workloads actually require the number of IOPS that the STEC can can handle. However, there's also an important technical point. There's a big difference between putting an SSD into a server as a stand-alone drive, and putting it into a storage array. In the first instance, the storage array is very likely to be incapable of supporting the total number of IOPs that everal STECs (you simply runn out of the array's internal capacity). That would make all those theoretical IOPs unusable.
The second point, is that an array with appropriate software can mask some of the limitations of lower cost SSDs. The most obvious one is "roll-up write optimisation" where the array stores up multiple writes in NV Ram for staging out. Doing this properly is complex, but achievable.
So the choice of Intel vs STEC within an array could well be a good choice on price/performance grounds. Put the higher performance SSD into an array and you well not see anything like the full benefit anyway. Put a STEC drive into a serrver, and you are faced with the limiation of limited connectibility.