Outlook 2015: Small Tree's Corky Seeber - Maxing out IO capabilities in 2015
Corky Seeber
Issue: January 1, 2015

Outlook 2015: Small Tree's Corky Seeber - Maxing out IO capabilities in 2015

Corky Seeber
Small Tree
Oakdale, MN

When trying to forecast storage innovations for the new year, it seems like we could simply take last year’s forecast and just make all the numbers larger. 400GB SSDs are now 4000GB SSDs. 10Gb Ethernet is now 40Gb Ethernet. It doesn’t make for a very interesting read, does it? Simply put, those in the industry expect things to be a lot faster and a lot bigger every year.
In 2015, however, things will be a little different.  Here’s why:
When filling up a motherboard with “stuff” these days, grumbling about how much IO bandwidth is sacrificed frequently occurs. A typical RAID card can move about 1.5GB/sec. If you’re putting that RAID card into a PCIE slot that can handle 8GB/sec you’re wasting 6.5GB/sec! A typical response to such waste might be, “Next year there will be 12Gb RAID cards and SSDS.” Sure, but that’s only 3GB/sec. You’d still lose 5GB per second when putting in one of those cards.
The networking side of things isn’t any better. Slap a 4-port, 10Gb card into an 8X PCIE slot, and you’re still giving up 4GB/sec of bandwidth. There just aren’t any good answers to maxing out your I/O capabilities.
This is why 2015 is so exciting. As 2015 progresses, we can expect to see 12Gb Host Bus Adapters (HBAs), ZFS as a file system, 4TB SSDS and 40Gb Ethernet cards. SSDs and ZFS, combined with a large port count HBA, should have no trouble taking full advantage of an 8X PCIE slot. A dual port 40Gb card will have no trouble taking full advantage of an 8X PCIE slot.  As a result, we’ll finally have a chance to completely max out the capabilities of the CPUs and motherboard.  
Today, when filling up a motherboard with the latest technology, users are limited to around 9GB/sec. (let’s assume one direction since people usually read OR write in our industry. You’re either capturing or editing). If you need more than 9GB/sec., you probably need to look into a much more expensive system.
In 2015, it’s likely a single motherboard system (even with today’s CPUs) will move closer to 30GB/sec. That’s an amazing jump!
What’s intriguing about this change is that all these amazing CPUs that Intel has been cranking out every six months will finally get tested. With today’s I/O technology and spinning disks, you can’t find a server busy enough to tax the CPUs even a small amount. When a motherboard starts moving 30GB/sec., those CPUs will be humming. In fact, they may even be the bottleneck.
“Oh no! A new bottleneck,” you say? This is true. However, if you’re going to have a bottleneck, the CPU is the place to have it. When your CPU is maxed out, you can either buy faster CPUs, or you can rest assured that you are going as fast as humanly possible. Either way, a CPU bottleneck is a much easier fix than something more esoteric like a protocol problem or spinning disk limit.  

So as 2015 progresses, let’s all rejoice knowing that the tables are turning once again and we may see I/O actually outstrip what a CPU can handle.