My initial suspicion would be the user used bad cables. There's many cables that say they're capable of a speed when they are not in fact capable.
Equally, a Crucial X8 SSD rated for the same 10GB/s connects to both Macs at its rated speed.
This behavious has persisted across OS updates since Big Sur.
My current thinking is that there's some undocumented quirks in place in MacOS that scales speeds down with certain USB controllers.
> Cables used included a certified Thunderbolt 4 model, and the USB-C (data) cables provided with the cases. Again, each was verified by establishing SuperSpeed+ 10 Gb/s connections to an Intel Mac.
Edit: I did read the entire article. Like others have said here, it doesn’t match with my experience. But because nothing is clearly specified as to what’s used, the article is useless because nobody can compare to see if their setup is the same or different.
I can't understand why they did not put some kind of capability mark for cables/ports into the spec.
You're talking about a completely different thing from cables that claim to handle a certain speed but aren't built well enough to actually do so.
Just as a very simplistic analog DC example, if you have wires that are both sitting at 3V but one can only drive 100 mA while the other can drive 1A. If you only draw 50 mA they'd look near identical but as soon as soon as you tried to get close to 100 mA they'd both diverge heavily. You could advertise both at 50 mA for sales purpose but if they were hooked up with a bad high resistance cable they'd look very different.
The sound was transmitted digitally and didn't need that much bandwidth, so the only explanation is "dirty" power on the power wires, I think?
Anyway I grabbed a 3.1 gen2 SSD and plugged it directly into my 16" M1 Pro (Sandisk Extreme), and I got 850 MB/s read/write with his tool.
And that's supposedly one of the exact drives and laptops he tested. So something is going wrong for him, and it's 90% likely to be cables.
In your test, did you use a TB4 cable or a USB data cable?
I used a USB cable, but I retested with an active TB4 cable with the same results. And again with a passive TB3 cable to the same results.