Broadband speed very different depending on test site?

[bratman91]

Quite! You know that, I know that, but where in any of the promises made by ISPs in their adverts does it say that? It is no better than if car manufactureres advertised that their cars were guaranteed a top speed of 100mph at 100 miles per gallon, but this meant only downhill, with a 50mph following wind, with a 5-stone driver and with special fuel.

[licquorice]

It is extremely simple to determine what speed you are getting, download a large file from somewhere and time how long it takes and do the maths. Bear in mind file sizes are usually expressed in Megabytes whereas speed is expressed in Megabits per second, there are 8 bits on a byte.

[pippincp]

Test files available HERE.

[pippincp]

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@bratman91 wrote:

Quite! You know that, I know that, but where in any of the promises made by ISPs in their adverts does it say that? It is no better than if car manufactureres advertised that their cars were guaranteed a top speed of 100mph at 100 miles per gallon, but this meant only downhill, with a 50mph following wind, with a 5-stone driver and with special fuel.

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Rather a rediculous analogy.

The first thing you would have to do to get anywhere near guaranteed wireless speeds is find a solution to all the causes of interference. Here is a partial list.

• Microwave ovens
• Cordless phones
• Bluetooth devices
• Wireless video cameras
• Outdoor microwave links
• Wireless peripherals 
• PDAs, cellphones
• Zigbee - Wireless personal area network technology
• Fluorescent lights
• WiMAX
• Other 802.11 networks - this is known as co-channel and adjacent channel interference. Since other 802.11 devices follow the same protocol, they tend to work cooperatively – i.e. two access points (APs) on the same channel will share the capacity of the channel.
• Bad electrical connections can also cause broad RF spectrum emissions

[bratman91]

It’s not ridiculous - ISPs are encouraging false expectations, as would be car manufacturers making the sort of (extreme to make the point) claim that I hypothesised.

[pippincp]

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@bratman91 wrote:
It’s not ridiculous - ISPs are encouraging false expectations, as would be car manufacturers making the sort of (extreme to make the point) claim that I hypothesised.

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Then take it up with the ASA.

https://www.asa.org.uk/make-a-complaint.html

[bratman91]

I think that you know that that is not a realistic suggestion. ISPs are adept at casting their adverts with just enough ambiguity and lack of precision to avoid complaints being upheld by the ASA.

[bratman91]

In the real-world home environment, most of those influences can be discounted except in the very short term or in unusual circumstances. They are the sort of thing that ISPs trot out to convince users that this is NTDWM.

OMicrowave ovens - in use for very short periods and typically confined to the kitche

Cordless phones - possible although moving mine and switching them off has never had any effect

Bluetooth devices - theoretically, but where is the evidence that  bluetooth actually does impair wifi networks?

Wireless video cameras - again, where is the evidence?

Outdoor microwave links - microwave communications are line-of-sight, and transmitting and receiving antennae are located high up on towers.

Wireless peripherals - wifi printers and scanners, NAS systems, video streaming devices and tablets, computers and smart phones are all peripheral to the wifi router. The problem is that turning them all off rather defeats the object of having broadband

PDAs, cellphones - these operate in the Mhz range so should have no effect on wifi in the 2,4 GHz or higher range

Zigbee - Wireless personal area network technology - very short range and low data rate so unlikely to impact on broadband

Fluorescent lights - most homes have little or no fluorescent lighting

WiMAX - usually an alternative to standard cable /fibre broadband so not likely to be there as well. Perhaps some smart energy meters use it

Other 802.11 networks - this is known as co-channel and adjacent channel interference. Since other 802.11 devices follow the same protocol, they tend to work cooperatively – i.e. two access points (APs) on the same channel will share the capacity of the channel.

Now here, I agree with you that co-channel interference from the wifi routers used by near-neighbours can be a problem but not one that can easily be overcome. The signal strength from the routers of neighbours might vary considerably from room to room and, if they are using “smart” routers that choose the best wifi band depending on the rf environment, it is difficult to select a band that will not become as congested as the one you want to move away from.

Bad electrical connections can also cause broad RF spectrum emissions - yes, but likely to be intermittent spikes rather than sustained loss of speed

[gg30340]

jaypeegolf

Going back to your original question.

It is best to  use a wired connection which will generally give you the most accurate result.

If you are not able to do that you should run a speed test on your wireless device but be aware there could be a lower result in the speed test due to possible interference.

It should not vary too much compared to a wired test but if the speeds do vary by a lot there could be a wireless problem such as interference or with your device or router.

If you are getting wildly different results between two speed test sites I would use a few other sites and see what results you get. It may be that one site is reporting incorrectly, which can happen for various reasons.