Incorrect conversion between bps, kbps, mbps

[dwilliams-1]

Describe the bug
It looks like a factor of 1024 is being used to convert between bps, kbps, mbps, gbps. While appropriate for storage/memory, network throughput needs to be scaled as a factor of 1000 (1kbps = 1000bps, 1mbps = 1000000bps, etc). This would also be applicable for B, KB, MB, GB as well.

Details:

• Device: [Macbook Pro M1]
• macOS: [15.1]
• Application version: [2.11.18]

[exelban]

wat?

[dwilliams-1]

To add an example
If you start an iperf3 session using '-b 100m' to send 100Mbps, iperf3 will report 100Mbps.
-open activity monitor in and view network activity. You should see ~13.1MB/s (104.8Mbps - the byte counters on a system read with overhead included)

Looking at the stats application
-In application mode -> open stats (network in Bytes to match activity mon). You will see ~11.9MB/s (95.2Mbps). If we undo the use of 1024 and replace it with 1000 we will see expected values
95.210241024 / 1000000 = 99.8Mbps -- expected value

-In interface mode -> open stats (network in Bytes to match activity mon). You will see ~12.5MB/s (100Mbps). If we undo the use of 1024 and replace it with 1000 we will see expected values
10010241024 / 1000000 = 104.9Mbps -- expected value

When scaling network speeds, you use multiples of 1000, not 1024. Network speeds are a metric conversion vs storage/memory being based on binary multiples. Currently the network information is calculating Mebi(bits/bytes) per second instead of Mega(bits/bytes) per second. Both are valid numbers, however Mega is what is reflected by speedtest applications, os network tabs, etc. I am slow to trace things out here, but I think it stems from the reuse of the the units or getReadableMemory helpers.

[fiwswe]

To be pedantic this is the old discussion about metric vs binary units. KB vs KiB, MB vs MiB, etc. Originally computer people used the units wrong, i.e. to mean 1 KB = 1024 Bytes.

If the current numbers use the binary (1024) multiplier then the units should be KiB, MiB, GiB, …

See https://en.wikipedia.org/wiki/Kilobyte

I have no opinion on what values should be displayed. But it should be noted that practically all marketing material and end-user documentation, including the Finder on macOS, have been using the metric units (1 KB = 1000) for quite a while now. The only notable exception seems to be RAM size as no one would understand why a machine has e.g. 8.59 GB of RAM instead of 8 GB (actually 8 GiB).

[exelban]

thx, I will take a look at this later today