September 01, 2008

Maximum Download Speeds Will Always Vary, Caps or Not

Over the last week, there was a lot of talk around Comcast instituting a 250 gigabyte cap on your downloads for a 30-day period. The Web's collective opinion has always tended to believe in unmetered, unlimited access to just about anything, without censorship, so the news of restrictions had many up in arms. But the truth is, you'd have to really go out of your way to reach the cap, and be downloading around the clock, all while maintaining consistently high bandwidth. And no matter what you're being sold on commercials, real-world download speeds are typically much less than the maximum advertised.

For me, it doesn't seem all that long ago that downloading a 4 megabyte application, like Netscape Navigator, was an intimidating process which could take hours, and download speeds of 9 to 10 kilobytes a second would border on exciting.

But consumers began to demand more from their Web, including more images, more streaming, higher resolution, more videos, and ever larger downloads, in parallel with ever-increasing network speeds, from the pokey 14.4, 28.8 and 33.6K modems, to broadband, either Cable or DSL, from speeds at 384 Kbps to 1.5 Mbps and 4.5 Mbps. As you would expect, consumers are led to believe they will get those advertised speeds, and, that higher numbers are, of course, better.

I don't typically download extremely large files. Most videos come in through Apple TV, or on the TiVo. If I am buying albums on iTunes, it's usually only one at a time, and my BitTorrent use is incredibly infrequent.

This afternoon, I had the rare opportunity to stress out my network by downloading a 3.8 Gigabyte recording of Saturday's college football game of Cal vs. Michigan State - which I had seen live yesterday, but wanted to revisit parts, not having recorded it on TiVo. When I first launched the file in BitTorrent, the speeds were outstanding - more than a full megabyte a second, and after several minutes of this, it looked like the video would be on my laptop in a little over an hour.

I Was Getting Screaming Download Speeds... And Then?

But just as quickly as I had noticed how fast it was going, the speed was decimated, and hasn't recovered - which smacks of Comcast throttling my throughput. What had been 1 Megabyte per second or more almost immediately dropped down to a more pedestrian range of 100 to 200 Kilobytes per second, and at times, much lower - in the 20 Kilobytes to 50 Kilobytes range, making what at first looked like a short download something that will probably be an all day process, assuming I leave the laptop on overnight.

Regardless of whether I've been intentionally throttled, or capped, or not, truth is that nobody ever really hits their advertised maximum network speed, thanks to issues at the remote servers, caching devices, storage, or due to shared pipes that mean your mileage is impacted by that of your neighbors' activity. And unlike a car, where you actually have a direct impact on whether you will reach the listed top speed, when you're on the Web, you're at the mercy of everyone else.

These issues mean you won't really ever know how long it will take to download something, until it's done, and just because you purchased a broadband connection that's "twice as fast" as the competition, you might not see your actual speeds doubling. With the near-monopolistic broadband providers having the option to throttle down your use at a whim, to cap your total usage at a level they deem appropriate, or with so many other factors impacting network speeds, you'll never see a flat-lined maximum, either on uploads or downloads. But if somebody ever gets that fixed... look out... I'd find all sorts of new ways to abuse that power.