Fibre 500 "slow" via ethernet

[FatCat222]

Hi I've switched from virgin coax 660mbps to sky fttp 500 just over a month ago. 

Initially speedtests were all 500+ across the board - great. Then after a couple of weeks I noticed my speeds dropping off. Most of the time speedtest.net (desktop app) to structured communications and other servers is showing around 250mbps, it's variable sometimes 150 sometimes 350-400 very rarely at 4am it might test at 500mbps. 

I am testing on a decent desktop hardwired to the router with cat 6 (same settup as virgin where i had no speed issues)

I've tried disabling IPV6 to see if it made any difference but it didn't. I'm also aware of an apparently resolved congestion issue affecting derby which is near.

https://community.sky.com/t5/Archive/Fibre-speed-slow-down/td-p/4007689 

[URL=https://www.speedtest.net/result/d/da945561-8429-4720-9ce0-577fe36950ad][IMG]https://www.speedtest.n...]

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Any ideas/thoughts appreciated

Moderator note: removed image that included personal details

[Chrisee · Accepted solution]

@FatCat222 a few weeks ago Sky did  have a network fault which did cause some users to experience speeds limited to 250Mb/s. This was traced to a fault on some of their gateway servers which Sky tell us has been fixed.  The variable results of your tests does not indicate that is your issue.

Your connection should deliver 550Mb/s down and 75Mb/s up at the hub which tanslates into 500Mb/s down and 68Mb/s up at your device - the difference is down to network overheads which is why Sky advertise this as up to 500Mb/s.

If you are running your test with just your PC connected then the speed tests run on testers like Thinkbroadband are taken to be reliable. Obviously if other devices on your network are using the link the test are unreliable many devices use bandwidth while idle to upload and download data while idle especially if you use cloud storage.

Just like Virgin Openreach share fibre capacity between customers so theoretically there can be contention however that is unusual but if your neighbours are very heavy data users that is possible. That issue is discussed here https://forum.kitz.co.uk/index.php?topic=25816.15 Virgin services are apparently far more likely to be hit by comtention issues but this is down to luck depending on who you are sharing with.

Of course very few people can use all of the bandwidth they buy so this is not a practical issue just as your cars top speed is not important when driving on UK roads. Sky always market speeds as "up to" but if your speeds are consistently lower than the speed guarantee of 400Mb/s you can claim money back see https://www.sky.com/help/articles/sky-fibre-speed-guarantee but as you will see there are significant conditions.

[FatCat222]

Brilliant thanks for the info