Just about a month and a half ago I suddenly became unable to download large files from the Internet, be they a linked download or updates through the Mac OS Software Update. I was consistently greeted with this error message in Safari: SafariErrorDomain error 1, invalid checksum. Other browsers resulted in similar errors. If I could get a file down I was unable to mount the file as different corruption errors would pop-up then as well.
After exhaustive searching of the ‘net I found no solutions that worked. Other have had the same problem but there seemed to be no magic bullet solution to fix it. I posted a thread on the Apple Discussion Groups and have since seen several people who get the same error but on solution that has worked.
Assuming it was my Mac Pro, that is hardwired to the router, I started from scratch with a complete, clean reinstall of the OS on another drive. Still the same error. Then I discovered it happened on every computer in the house but by signing on to the neighbor’s wifi (with permission) I am able to download these updates. With that revelation I called Comcast. After nearly an hour on the phone we came to no solution. My Internet connection was their “Performace” package that was rated at 12 Mbps of download speed. I suggested to the Comcast tech that he sign me up, for free, to their highest package, Extreme 50 at 50 Mbps down, so I could test the connection over a few days and see if that solved the issue. He informed my that I couldn’t just sign up for free but I could upgrade to that package and cancel in 30 days if I wasn’t satisfied. That’s what I did.
After a reset of the router and modem I began testing the speed for the next month. First off I’ll say that this didn’t fix the download problem, the same error still occurs. My only other idea is to get a new modem. I’m currently running a DOCSIS 3.0 Motoroal Surfboard which is compatible with all of Comcast’s fasted speeds so that doesn’t seem like a solution that will work but I don’t know anything else to try at this point. But this blog post isn’t about the download error but rather the Comcast claimed download speed …
As I tested the speeds on and off for the month I consistently came up with very similar results. They were usually always around 25 Mbps down from Speedtest.net and Speakeasy and usually double that from Comcast’s own speedtest web site. I found that very strange. Only Comcast’s speed test showed my download speeds to be anywhere near the claimed 50 Mbps (and it was usually over just a bit). By contrast all the other speed test sites consistently showed nearly half that claimed speed. A couple of conversations about this with Comcast tech support only had them say that someone would need to come out and physically test the line. I can buy that there could be a physical line problem since I apparently wasn’t getting the claimed 50 Mbps download speeds. But they could never explain why the Comcast speed test was twice all the other Internet speed tests. When I specifically asked for an explanation to this strange phenomenon the Comcast reps could not (or would not) explain. When I inquired about this via Twitter the usually reliable @comcastcares account gathered some information but never returned an explanation.
So the question here is: why did Comcast’s own speed test always show nearly twice all the other speed testing sites? Why was it only Comcast’s speed test that provided download speed results that met their claimed download speeds? There might be a problem with my line that won’t let it reach the highest available download speeds but the Comcast speed test results really makes this all seem very fishy. Here’s the speed testing results on the last day I had the Extreme 50:
Something there just doesn’t seem right. I’ve downgraded back to a different package. It’s not the Performance package that I had before (I don’t know what the name of it is) but it’s a notch faster … for less money than what I was paying for Performance. That’s because I get one of those “for 6 months” pricing discounts since I haven’t had a discount in nearly a year. As we all know, that’s how Comcast does things, raise rates for everyone but new customers. If you currently have Comcast then give them a call and try to get one of their current promotional discounts: they are ALWAYS running one – why not just lower rates for everyone? I guess they’ve got that new XFINITY thing to pay for. What is XFINITY anyway other than another excuse to raise rates or sell me on Comcast phone service?