Slow macos 27.2 download speed

EvertsRozz wrote:

TLDR; very slow macos 27.2 download speed while on beta 27.0. Internet and storage are not the problem. How to fix?

Could this somehow be related to the fact that im on beta?

I don't think it is related to your previous use of the beta.

My experience -- we have about 550 Mbps download speed and the 27.2 download started out at ~ 100 Mbps, showing 30 minutes to go. Then it increased to 400 Mbps when my wife started streaming high definition videos from Netflix ... not what I expected. Time to go then showed 8 minutes. Then the download speed went repeatedly from 450 Mbps to ~ 10 Mbps then back to 450o Mbps, which effectively cut the speed in half, overall, roughly. It did finish however and complete the installation. The slowest part for me was watching the odd download speed pattern. This was on a new M5 Macbook Air.

I have a guiding principle: a watched update never finishes.

Etresoft has mentioned his theory (in this thread and also in others) that this might happen because priorities get shifted for download bandwidth when one starts to stream high rate video from a commercial provider, or when one opens a VPN, which prevents the priority algorithm from working.

I guess I would not use a VPN because they can interact unpredictably with macOS. Also, my experience with VPNs provided by my employer to access their proprietary corporate network is that the VPN cuts the download speed in half anyway, which is what I saw during my download (jumping between 450 Mbps and 10 Mbps towards the end).

Since 27.2 is relatively new the Apple servers may be having trouble keeping up with the demand. Maybe you just need to let it complete overnight or wait some days and try again when the servers are not as busy.

When this happens to me, I just turn on a VPN. Then it downloads at a regular speed. I guess the VPN confuses the content delivery network or something. I used to do this regularly a few years ago when this was common. Then I saw it again on a recent update. My old VPN trick still worked.

You can check the status of Apple's systems on their site. Software Update is 'green'.

Apple - Support - System Status

However, downloads are served regionally and loads vary. The time remaining is also definitely non-linear – it jumps around (usually down, sometimes up). Bottom line, just wait. Or cancel it and try again tomorrow.

You'll just have to wait it out. There are many factors that come into play when it comes to downloading anything on the interwebtubes including where the server you're getting it from is located, the load on that server, the load on that servers connection to the network, the load on all of the routers and switches in between, etc.

Be patient.

I have a download speed spec of 350 and I did two units that took ~30 min each to download and install. Not sure why your process takes hours even with the large download size (>17GB) unless some server issue. Sometimes a provider will cap the speeds if a file size is too large.

Alright, thanks for the info!