Marketing always says the bus speeds. Theoretical throughput.

When we post actual "results", we use real world benchmarks (like AJA System test), with published CPU and drive configurations, on freshly created volumes. I would have to look that up for your setup, or repeat the test, to give you real world data.

But use AJA System test for testing, with these settings, so you can compare with other results:
Go to the App store and get AJA System Test Lite.
Run AJA, set resolution to 8K video, Codec to 16bitRGBA, and file size to 64GB.
Next, in settings, check "Dual DMA engine".
Select your volume to test.
See what results you get.

Its as close to a "standardized" result as you can get.

M series is faster on writes than intel, as its more efficient on CPU usage.