Different upload and download internet speed

The wifi speeds (up and down) are also lower for my iMac compared to my MacBook Pro. Can it be simply a question of a newer model supporting higher speeds than an older model?

That is easy.. yes, the later laptop is superior in so many ways.. better wireless card and antenna and just designed from ground up as a wireless device.. the iMac is still intended as desktop machine which should be hard wired.

However, on iMac (late 2012), the download speed is consistently coming under 450 mbps while the upload speed is over 900 mbps.

SMB has some issues .. the speed of the ethernet down should be equal to up but it can relate to source..

I would not have thought the hardware differences would be too great. Have a careful look at IPv6 configuration in both the laptop cf the iMac.

Post the actual ethernet being used via your system report.

Also look closely at the CPU usage.. some wired connections are more efificient than others.. drivers differ.

I think you are going to have a merry chase finding the cause. But local network tests are essential..

Tesserax might have a few more comments.

Thanks.. but the manual timing and calculation rather than automated is a bit clumsy.

I asked one of the guru's here.. he suggested

Downloads - Wired and Wireless Network Analysis Software by TamoSoft

The free download has a server and client .. load the server onto one computer and client on the other.. gives a chart that looks like this.

I am out of edit time.. my brain sometimes takes a while to kick in.

Downloading from Internet needs a suitable location to store the file.. if that is stored in RAM it is very fast.. how much free RAM do you have on the iMac.. or you need SSD drive.. Remember spinning drives are SLOW>. SLOW SLOW .. VERY SLOW..

The MBP probably has SSD.. and Apple used Super Fast card type. That will give a location for files to be saved to..

So what you are seeing might really be nothing more than artifacts of the machines themselves.

The right way to start is iperf tests on local lan ..

Let me suggest a simple test.

In order to figure out what is the problem (if it is real or not).. do a few tests copying very large files between the two computer.. something like a Mac upgrade file, but a movie or anything you like.. around 5GB single file is what you want.

iperf is command line so you need to know what you are doing. And later OS doesn't come preinstalled.. I am guessing both computer are running latest OS with all the patches.

Set each computer with IPv6 on link local only and wireless off. Both connected via the router with ethernet.

Set each Mac to share the hard disk so you can do the copy each way.. then copy the file from each computer to the public folder on the other.. From iMac to laptop and then laptop to iMac.. use activity monitor to watch how it progresses..

I will check if there is some easy to use software that does iperf like tests on a Mac.

Use the software download I recommended in the post above.. it is much easier than messing around with sharing files over the hard disk.. although in the end that is also a good test.

The software method is much faster and will quickly show up a problem.

You don't need to install anything.

macOS already has the nc (netcat) command that can be used to test Ethernet speed. Please, see the link below for details

http://deice.daug.net/netcat_speed.html

Hi! I have a related issue and I am hoping that you might be able to shed some light on it.

I have recently subscribed to 1 gbps synchronous internet service from CenturyLink. I am getting close to over 900 mbps up and down on my MacBook Pro (late 2013). However, on iMac (late 2012), the download speed is consistently coming under 450 mbps while the upload speed is over 900 mbps.

Any suggestions on how to improve the iMac download speed to over 900 mbps as it should be?

The wifi speeds (up and down) are also lower for my iMac compared to my MacBook Pro. Can it be simply a question of a newer model supporting higher speeds than an older model?

Thank you.

Hi! I have a related issue and I am hoping that you might be able to shed some light on it.

I have recently subscribed to 1 gbps synchronous internet service from CenturyLink. I am getting close to over 900 mbps up and down on my MacBook Pro (late 2013). However, on iMac (late 2012), the download speed is consistently coming under 450 mbps while the upload speed is over 900 mbps.

Any suggestions on how to improve the iMac download speed to over 900 mbps as it should be?

The wifi speeds (up and down) are also lower for my iMac compared to my MacBook Pro. Can it be simply a question of a newer model supporting higher speeds than an older model?

Thank you.

Hi! Your technical understanding of the topic is much more advanced than mine. So please bear with me while I try to comprehend what you recommending.

First, thank you for the explanation regarding the difference in the wifi speeds. That makes sense.

Second, I am using the same ethernet cable to test speed on iMac and MBP. So help me understand how iPerf test on local LAN will help.

Third, I have a fusion drive for iMac and an SSD for MBP. I am using speediest.net to test the internet speed. iMac RAM has 16 GB 1600 MHz DDR3 while MBP RAM has 8 GB of the same. Would the speed test be affected by the RAM size and the drive type here?

Fourth, I don't know how to interpret CPU usage to assess the efficiency of a wired connection. On iMac, the top three CPU processes by CPU time are kernel_task (26:14), WindowServer (20:04) and instalid (16:38). On MBP, the top three CPU processes by CPU time are photoanalysisd (20:53), Safari Networking (8:22) and Safari (4:57). Needless to say that the iMac is my workhorse.

Thank you again for taking time to help me troubleshoot the problem.

Thank you so much. I will run the test.

😮 WOW. Almost 1Gps of Internet bandwidth

802.11ac speed of 1.3Gps is theoretical. Average speed is what you recorded.

Anyway have a look at this page

Upload speeds are always significantly lower than download speeds.

http://www.bandwidthplace.com/download-speed-vs-upload-speed-whats-the-differenc e-article/