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Downloads hog network resources

I was in the middle of a zoom meeting on a relatively new iMac Pro, and tried to download a file through a web browser. Immediately, the zoom client started faltering and I got a message there "Your internet connection is unstable".


I've noticed this with other downloads, as well. If I start a large-ish download (>100MB) then nothing else downloads, including simple web pages I've already visited within the last hour and should be cached.


This has been the situation since at least my upgrade to Big Sur 11.2, but I didn't pay as much attention prior to that update. Is this by design? My iMac Pro is hardwired directly to my router, and I have 100MB fiber internet. So from the hardware side of things, this kind of behavior seems extremely unusual.

iMac Pro

Posted on Sep 15, 2021 1:14 PM

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Posted on Sep 21, 2021 3:30 PM

UPDATE: the problem seems to have been that the mesh router was behind the ISP router, and the ISP router was not set to bridged mode. I started the latest XCode update, which is over 1GB, and normally it would bog down every network connection on my iMac, but so far no problems loading a bunch of different things, and my office connections did not die like usual.

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Sep 21, 2021 3:30 PM in response to sumyung gai

UPDATE: the problem seems to have been that the mesh router was behind the ISP router, and the ISP router was not set to bridged mode. I started the latest XCode update, which is over 1GB, and normally it would bog down every network connection on my iMac, but so far no problems loading a bunch of different things, and my office connections did not die like usual.

Sep 15, 2021 2:37 PM in response to sumyung gai

sumyung gai wrote:

My iMac Pro is hardwired directly to my router, and I have 100MB fiber internet. So from the hardware side of things, this kind of behavior seems extremely unusual.

Don't you mean 100 GB?


Download and run the SpeedText app to see what your're getting in the way of up and down-load speeds. With my 100 GB fibre optic connection I get this:




Have you installed or run any "cleaning", "optimizing", "speed-up" or anti-virus apps on your Mac?


Sep 15, 2021 3:41 PM in response to sumyung gai

That should be sufficient. I've not tried to download files while on Zoom so can't address that part of the problem. Have you installed or run any "cleaning", "optimizing", "speed-up" or anti-virus apps on your Mac?


Download and run Etrecheck. Etrecheck is a diagnostic tool that was developed by one of the most respected users here in the ASC and recommended by Apple Support  to provide a snapshot of the system and help identify the more obvious culprits that can adversely affect a Mac's performance.


IMPORTANT:

Before running Etrecheck assign Full Disk Access to Etrecheck in the Etrecheck's Privacy preference pane so that it can get additional information from the Console and log files for the report:


Also click and read the About info to further permit full disk access.



Copy the report



and use the Additional Text button to include the report in your reply.



Then we can examine the report and see if we can determine what might be causing the problem.


Sep 15, 2021 1:17 PM in response to sumyung gai

I will also add that because I work from home 90% of the time, if I'm asked to download a large file my remote connections to work all die off one by one. Some of them permanently close themselves, but they all of them do the icon jump in the dock and give a warning that the connection was lost. I cannot believe that the built-in network is THIS bad that it cannot handle splitting a network stream to keep already running connections active.

Sep 15, 2021 1:26 PM in response to sumyung gai

What is the uplink speed on your internet connection?


Do some tests.


Very often, the uplink speed is quite a bit lower than the download speed. Unfortunately, why can happen is that the high download speeds allow large transfers to run very fast, which generates a large number of acknowledgment packets to go out very quickly, sometimes saturating the uplink.


Once the uplink is saturated, the downlink will stall.



Sep 15, 2021 1:34 PM in response to woodmeister50

Just want to point out that "only" 100Mb fiber means I'm getting "only" 100Mb up and down, compared to cable, which is more like 100Mb down but maybe 10-20Mb up.


I have it narrowed down to the iMac or the router, but I wanted to verify that the Apple side wasn't supposed to be like this, or maybe there's a hidden setting that can be changed to make it work correctly.

Downloads hog network resources

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