I've read that often ISPs make exceptions for Ookla and fast.com speed tests by removing any sort of throttling to produce the best possible test results.

I expect it isn't as easy for ISPs to treat Cloudflare like this, as it just looks like normal internet traffic.

Got a source for ISPs doing that for fast.com? Fast.com is netflix, so the same argument applies there - if you get 300mbps on fast.com you should get it on netflix too

This is why Netflix runs fast.com, so that if an ISP wants to cheat on speed tests, people are still going to get those cheated speeds even when they stream real Netflix videos. Really clever.

And the other way around, if they throttle Netflix then that'll show up in the speed tests.

Indeed, that's part of what motivated netflix to make fast.com.

is it possible for ISP to distinguish Netflix video streams from connections to Fast.com ? (and throttle them differently)

PS: my latest ISP router doesn't let me change DNS to my local pi-hole. haven't explored all options yet - just got new one 2 days ago -- but currently my DNS queries are going to whatever is the default set by my ISP.

I've never used a pi-hole; but assuming it works as a DHCP server and a DNS resolver, then you should only need to disable DHCP in your router. I've never seen a router than wouldn't let you disable the DHCP server.

What's the motivation to rent an ISP router? That's a lot more control than many people would prefer to give to an entity that is likely anywhere from "greedy and dumb," to greedy and outright hostile.

Having DOCSIS, I buy a modem, and own my router. I am aware that for more exotic technologies like fiber, a rented/ISP-owned 'modem' or network terminal of some sort may be compulsory, but a router is a bridge too far (no pun intended) for me.

(Not in the US.)

Well, here the major ISPs are bundling the FTTH Fibre modem and th WiFi router into a single device.

I wanted to experiment with Mesh router for better wifi coverage but the prices of mesh routers here are high, brands unproven, and returns policy iffy. So I went with the mesh router option offered by ISP for ~1 USD a month.

(I do have a spare wifi router to add if I really feel like. Our location has occassional power outages and the backup power doesn't flip on instantly enough - causing router restarts if we don't add a small battery powered backup to each individual router. So the setup gets bulky and messy.)

Oof. With the power especially, I can see why you would make that call.

On the positive side, they're ripping you off much less than our ISPs do in the States. They usually charge $10-20 a month here for some device which is usually using technology from about 5 years ago (when it's first installed, that is - they don't swap you a new one when technology improves of course, unless you raise a fuss AND they've actually adopted a new model).

I will admit, sometimes it's tempting because you could in theory expect them to support their company-owned hardware. But in practice for us that just means we can complain at some minimum wage call center "tech support" about how the device stops working until rebooted X times a week, and they will offer the choice to reboot it again or to make an all-day appointment for some installer to show up with another identical refurbished modem/router/AP that will have the exact same buggy software.

It's theoretically possible, but practically difficult. They can tell whether you loaded something from fast.com or netflix.com prior to the data stream, or they can give full speed initially and throttle after a minute or two (longer than people's patience for a speed test, but far shorter than a movie).

It's difficult because Netflix can respond to any such technique by taking steps to make it less obvious, so you just end up with one of these cat-and-mouse games.

This was my understanding, too. Anecdotally, I've always seemed to get slower results on fast.com compared to Ookla/speedtest.net/my ISP's speedtest website (the latter of which all seemed to show similar results, leading me to believe that fast.com was exempt from this sort of prioritization).

I think fast.com hits netflix's cache server. Pretty much all isps have one provided to them by netflix.

There's an alternative explanation is that it's possible your ISP hasn't learned to prioritise this speed test traffic unlike other speed tests, and that this is more reflective of general real-world performance?

Odd to see several posts like this, nobody considering that the other tests they've run might be "over-reading".

I know that when I download a large file, it usually hits the advertised speed. So I'm confident that I can saturate my broadband with normal use.

Cloudflare doesn't even get close.

How would they "over-read" and be so accurate?

I'm able to hit 800 down and 400 up on the Cloudflare app. On fast.com i get 980/980, similar with ookla.

I wonder if it could be that various handoffs with cloudflare's network are more busy, but we don't really notice because we're not doing speed tests on it. :)

Ookla traffic is known to be prioritised by ISPs. Maybe ISPs just haven’t caught up with Cloudflare yet and what you’re seeing now is more realistic speeds.