Comcast and Net Speed Tests

JimDaGeek writes "I recently moved to Columbia, SC where I have Time Warner as my cable ISP and pay for an 8 Mbps connection and have been very happy with the service, speed, and reliability. In contrast I have heard bad things about Comcast. So now that I am up in the Philadelphia PA area visiting my parents, I decided to test out the speed and reliability using the Speakeasy speed test. The results surprised me. Here are the reported download speeds in Kbps: New York, 18,946; Washington, 15,821; Atlanta, 11,257; Chicago, 10,042; San Francisco, 4,230. What is going on? I know my father is not paying for a 10+ Mbps connection. Is Comcast giving priority to popular speed-test sites?" From Comcast's site, in the Philadelphia area they seem to offer download speeds of 6 or 8 Mbps, with an option for a "PowerBoost" to 12 Mbps on large files. This wouldn't explain the results JimDaGeek got of almost 19 Mbps down.

Update: 07/10 12:07 GMT by KD : A friend in Massachusetts had a tree fall on his house. The Comcast guy who reconnected the lines told him that they are boosting the line speed to 20 Mbps down / 2 Mbps up in certain areas to be more competitive with Verizon FiOS.

Comments

PowerBoost uses compression

[rdean400]

I'm wondering if the speed test uses a data block that is more compressible.

PowerBoost

[the_cowgod]

The Speakeasy test regularly reports over 20Mbps on my Comcast connection. The "PowerBoost" feature allows basically uncapped speeds for the first ~15MB of a transfer, then it drops down to the normal 6Mbps. I can easily see this effect when doing large downloads with my UsenetServer account. It does inflate speed test results, but Comcast does not appear to be favoring the test sites in any way.

Re:Time of day?

[MrShaggy]

Since cable bandwidth is shared, wouldn't the time of the test matter? I've noted (very unscientifically) that my Internet seems slower between roughly 7-9pm (on Charter in Los Angeles area). I look at the difference between cable and dsl as 2 different ways of getting to a train-station.


Cable might be like taking a bus to the station. There might be other people there. However, its not that significant.


Dsl is like taking your car or a cab to the station. It definitely is not a shared ride into the station.


The one thing that happens is that everyone gets off of there rides, and they all take the train out. Pretty much at the same speed.

Of course during that time of the day there are many people on the internet, so it won't matter what you are using. Its somewhat insignificant how 'slow' it is. The only thing that kills the dsl is how far away you are from the office. Thats pretty wild. The thing is that you can get speed tests from eith side of the country or even planet. So even if it isnt the rush hour here, it will be elsewhere.


Thats why I think most dsl ads are so misleading.

They are up to it.

[WindBourne]

I tested my comcast 6 MB with and got 1.2 MB., but With speakeasy, it ranges from 8-12 download. It is obvious that they are selectively caching.

Re:Lots of factors...

[pokerdad]

In short: call comcast, ask them to look into it. They've almost always been helpful, through all the various company changes: MediaOne, RoadRunner, etc.

As someone who used to work for Comcast allow me to say rotflmao. Either you are one lucky sob or you are lying.

Just as a matter of example (one among many) during the entire nine months I worked for Comcast the entire state of Illinois never left the outage board. That isn't to say that no one in Illinois ever had a connection, but many people had little or no connection and we were under instruction to do absolutely nothing for anyone from Illinois - just keep BSing them till they gave up.

Re:Giving Comcast Props

[Firehed]

As a slashdotter, I doubt it, but could you have confused Mbps with MBps?

When I was on Comcast (actually, come to think of it, I think I am here too), I usually got speeds right around what was advertised. Hell, I got a speed boost when they took over Adelphia.

Re:Download a linux distro

[grcumb]

Someone above mentioned using jigdo to get all of debian, but even using wget to get a full dvd or cd set of some distro will provide you with a good data point.

I beg to differ. Downloading a single file is only indicative of how fast a particular connection is between two particular points. P2P, if it's allowed to, saturates the network with two-way traffic to numerous end points. If - and this is a big if - there were no constraints on P2P traffic at large on our networks, I would consider it a near ideal measure of TCP traffic capacity in the real world.

In fairness to your comment, you characterised that single download as a 'data point'. Strictly speaking, that's a valid statement. How to get enough of these data points to provide useful insight isn't adequately answered by either of our suggestions, and frankly I'm a little doubtful about the online speed tests being discussed here, too.

Re:REAL BANDWITH TEST

[X0563511]

And further down are links to other systems... most are working

Re:Time of day?

[Short Circuit]

That's nothing. I was in a vacant computer lab in Michigan during Spring Break, pulling Debian CD images from an FTP server in Germany (best transfer rate I could get; Jigdo never worked for me, and there weren't official torrent trackers at the time. {Are there now? Switched to Ubuntu a couple years back.})

The door to the lab bursts open, and a couple techs started methodically checking port labels on all 69 of the PCs, then started checking the Macs. (I was on a Mac 'cause those were the only machines that had burners.) They let me finish downloading disc 12, but told me not to start disc 13.

In 2003, it was kinda noticeable when someone had three simultaneous 200KB/s FTP transfers running. Fortunately, I wasn't in violation of the Acceptable Use Agreement, as I hadn't installed any unauthorized software...