Speedtest.net
Niki Wienberg
What is FAST.com measuring? FAST.com speed test gives you an estimate of your current Internet speed. You will generally be able to get this speed from leading Internet services, which use globally distributed servers.
Why does FAST.com focus primarily on download speed? Download speed is most relevant for people who are consuming content on the Internet, and we want FAST.com to be a very simple and fast speed test.
How are the results calculated? To calculate your Internet speed, FAST.com performs a series of downloads from and uploads to Netflix servers and calculates the maximum speed your Internet connection can provide. More details are in our blog post.
What can I do if I'm not getting the speed I pay for? If results from FAST.com and other internet speed tests (like dslreports.com or speedtest.net) often show less speed than you have paid for, you can ask your ISP about the results.
The most common question that people ask us is why their results here differ from speedtest.net. I want to explain something that may help you understand why this is.
According to the Ookla Wiki [updated link] the following is true about your tests taken at speedtest.net...
Throwing away the fastest 10% and slowest 30% of the results in my opinion does not make for an accurate test. Isn't THAT the data that you're here to see?
Also note this isn't only true for speedtest.net. Ookla is huge, most of the speed tests online run their software.
Source: wiki.ookla.com
Multithreading makes your connection look better
Ookla speed tests are also multithreaded. Meaning that they open more than one connection to the host and combine the speeds. This often can mask congestion issues. For instance, imagine that you have a pipe along your route that's limiting you to 10 Mbps. If you open more than one connection through that pipe you'll be able to achieve a faster speed... but testing that way will not clue you in that there is actually a problem along the route. Remember, you shouldn't have to multithread your connection to pull your full speed.
Multithreaded speed tests, like the majority out there, are designed to benefit the Internet provider not the consumer. They often display your maximum throughput not your throughput over the course of an entire upload or download. Omitting the worst portion of your test resulting in inflated scores that may make you feel warm and fuzzy but aren't going to help you see and resolve connection issues.
Multithreading can show that you're able to max out your connection by combining the speed of concurrent connections but a great connection can max out without having to multithread.
So, if you have to multithread your connection to get your full speed, you should be asking why that is. With TestMy.net it's instantly apparent if there is a congested route. Your speed here reflects the actual loading time of data within your browser... not the combined efforts of multiple threads being altered (dropping the top 10% and bottom 30% of the results) and added together, all through a plugin that isn't suited for the task.
If you'd like to multithread with TMN, I offer that as well. Try the multithread speed test. TMN's multithread test gives you the option to select from an array of servers. Allowing you to test across multiple routes, to more than one server at a time. TestMy.net is the only Internet speed test with this ability.
So THAT'S why your results differ. -- TestMy.net is a harder test to ace and a lot less forgiving than other speed tests. But isn't that what a benchmark should be?
:: EDIT ::
Another thing to consider is if you're running windows, particularly if it's older than Windows 7 you may need to tune your TCP stack to see your full speeds. Windows doesn't always come out of the box optimized for fast connections. Flash based speed tests fail to detect this problem.
To make this change for free I recommend TCP Optimizer. This makes changing those settings very easy and nearly fool proof. Just open it, slide the bar over to your speed that you're supposed to have, check "modify all adapters" ...apply the settings and reboot. You should have faster speeds after your re-test if that was the problem.
Here's an outside source talking about exactly this issue, I'll hunt down more examples. >> Download Speed Test - Something fishy?
A few related topics ::
At times I'll use there service for a server as close to me as possible , so i can isolate the issue a bit more , true enough , thier closest server generally gives me very close results to yours here at tmn , imagine that.
i usually see very different results than here, when my internet is having issues speedtest.net doesn't usually detect them at all it will show my full 50/5 where as here i can see my service is really suffering and only receiving half that
my results there are always out of this world...great numbers...like vanity sizing...but if i really wanna know if these jeans make my butt big tmn is the looking glass i believe...not always the numbers i wanna see...but hey sometimes the truth hurts...
like right now i'm having an issue that began in early april...most likely my modem...testing here toldl me something is wrong...i called cox and they wanted me to do a test using speedtest inside their network...i said i wouldn't go by that (first off i don't go to any websites or dl anything off their network that i know of)..i told her .that i could already tell her that what it was gonna say...25+...here lately i'm getting 8 or so...so just for the hell of it i took a test there...yep...34...if i went by them i'd never know i have a problem at all...so yes these jeans right now do make my butt look big...but they lied to me
I use many speed test sites. Testmy.net is by far the most " real time " results you are going to find. Other flash based speedtest sites , aka speedtest,net show your absolute best connection speed with a huge overhead buffer. That is considering NOONE around you is using the internet and you are the ONLY one online that day on your node lol.. If you want accurate, right now speed test results, i use testmy.net. I want to know my connection speeds in real life, not what they possibly can be in absolutely optimal conditions ( again due to the overhead) .
Good point... but you failed to factor in that I run this site and I'm purposely trying to break things as I develop. That score is no doubt inaccurate... but it was scored that way durring trials... most likely that score wasn't even logged by the public site that you all see
Alot of times you cannot choose the closest server on speedtest.net. If i choose Tampa, which is 50 miles away, or Miami, or ANY of the close servers ; i get a 1/4th of my speed. But if i choose Atlanta GA , 900 miles away, or Huston TX , or any of Texas for that matter, i get top speeds Go figure.
I didn't originally build this site to be used by anyone except myself... it was part of my 'toolbox'. A way for me to ensure that when I left a customers house they were getting what they paid for. ... I wouldn't build or use a tool didn't serve it's purpose. (that goes for any tool) I'm not a cable installer anymore but I'm my own biggest user of the service. Many of the features the site now has came from my own need for that service. My point is... this site is a tool, not a novelty.
if i go by that then i'd never know anything is wrong with my connection. but the ISPs can't fool me... i'm going to keep having them come out and look into my issue forcing them to spend thousands until they fix it and give me what i'm paying $89.99 a month for, a good company wants a happy customer and i will be one when they fix my problems which they are trying to do
I've just swapped out my old cable modem (Motorola SB5101) for a new Motorola SB6120, which is a DOCSIS 3.0 modem. It took Comcast a few minutes to get the new model number and ID to reset it (remotely) to get me reconnected. As soon as I was up again, I tested my connection speeds. After a couple of hours, I tested my speeds again. Just right now:
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