Comment by ChrisMarshallNY
6 hours ago
As always, these testers (the affordable ones) are capable of testing continuity, and, I guess, the cable chip report.
If you want to test bandwidth, that's a five- or six-figure bit of gear.
6 hours ago
As always, these testers (the affordable ones) are capable of testing continuity, and, I guess, the cable chip report.
If you want to test bandwidth, that's a five- or six-figure bit of gear.
This keeps needing to be pointed out every thread this appears on. Plenty of cables have eMarkers that claim "40Gbps" or whatever speeds, or support 240W PD...but absolutely cannot deliver either of those. And none of these consumer level testers can test either of those claims.
Resistance measurements can cursorily test claims of 240W but resistance changes with temperature which changes with current...so unless your tester puts 5 amps down the wire for 5 minutes and then tests resistance it's not a very good test.
Yeah — "the eMarker said 40Gbps" is basically the same problem as trusting the print on the jacket.
For home use I've ended up treating real capability as an empirical property of the specific cable+port+device combo: does this exact cable drive this monitor at the mode I want, under load, for an hour? If yes, it gets a colored heat-shrink band and never leaves that use case. Everything else is a phone/charge cable until proven otherwise.
Why on earth is so much more expensive than an arbitrary pair of devices that could max out a cable?
Think about it.
You need to generate a precise, calibrated, 40GHz signal, transmit it, then precisely measure the returned signal for phase, amplitude, and waveform integrity -at that speed.
Oscilloscopes and logic analyzers that run at that speed, are damn expensive.
It’s much cheaper to just buy your cables from Apple or LTT knowing they tested them on a 6 figure testing rig.
I throw out every usb cable that comes bundled with devices because they are literal junk.