Moore’s Law and Bandwidth Consumption

Most in IT are familiar with the concept of Moore’s Law, whereby processor capability tends to double about every two years.  To a certain extent, this happens with networking equipment, with their capacity increasing at a steady rate, although probably not the same rate at processors.

Benefiting from Moore’s Law to a great extent are load balancers/ADCs, where the lowest end device from just about every vendor can handle traffic loads in the 50-100 Mbps range.  Of course, throughput isn’t a terrible way of measuring performance capability of a load balancer (100 Mbps of large file downloads is a heckuva lot easier than 100 Mbps of tiny file connections), but it does relate well to one very important factor in web site serving:

How big is your pipe?

Businesses of all sizes have seen steady increases in their available bandwidth to be sure, but while the growth may be steady, for the most part it tends to be a slower growth rate.  Much slower than doubling every 18 months, like in Moore’s Law.   The result is that increasingly that the lower end offerings from vendors are more than sufficient to run a larger share of web sites out there.

There are a number of reasons for this.  We’re no longer experiencing the exponential accross-the-board growth rates in users that occurred during the dot-com boom.  While there are some sites going through a growth explosion, for most websites in this economic environment, growth rates of any kind are fairly extraordinary.  So extra bandwidth isn’t in as high demand. Secondly, if you’re hosting your own data center as many large businesses do, getting extra bandwidth is often time consuming.  Moving from a single DS3 (45 Mbps) to an OC-3 (155 Mbps) is going to take some time to get that order fulfilled.

Cisco’s ACE 4710 appliance comes with a default license of 1 Gbps of throughput.  F5’s entry-level BIG-IP 1600 LTM maxes out at 1 Gbps.   In the Enterprise market, 500-Mbps to 1 Gbps is about the rock bottom in terms of performance capability.  Yet many of the high-end clients of these vendors don’t push nearly that much traffic.

Companies that aren’t media or mega-content providers (such as Google, Youtube, Yahoo!, Facebook, etc.) that have web applications serving customers or businesses typically don’t go above 100-200 Mbps in traffic, even for some Fortune 500 companies.  Of course, there are exceptions, and there are quite a few factors involved in determining the traffic characteristics of a site. Companies that are offering media such as streaming video or audio often use third-party content providers, such as Youtube or Akami, so as to keep that bandwidth off their own pipe.

So we’ve got all this idle CPU time, so why not make use of it?  That’s what many vendors are doing, in both the enterprise and value markets. With the steady rise in CPU power while bandwidth consumption lags behind, vendors are throwing more and more capabilities into these devices to take advantage of the unused CPU cycles, such as caching, compression, Layer-7 inspection, etc.  Vendors are offering more functionality with the greater power they have available to them.