The USB "standard" is decending into chaos
- Thread starter Sunray
- Start date
UnderOpenSky
baseline neural therapy
Like honestly. What the suffering fuck.
USB 3.0 type B.
OK you guys have a point
NoXion
Craicy the Squirrel
Is that something in your possession? What's it for? Never seen anything like it. It's apparently one of these:
I didn't realise there was such a proliferation of different connectors.
UnderOpenSky
baseline neural therapy
Is that something in your possession? What's it for? Never seen anything like it. It's apparently one of these:
I didn't realise there was such a proliferation of different connectors.
Yeah. Just got a new monitor and it connects to the PC so that the USB ports on the monitor work.
platinumsage
HaveMyPassword123
I recently bought a new torch and it recharges using mini-USB. Of course when I need to charge it I inevitably find a micro-USB cable first 
teuchter
je suis teuchter
So, I eventually got an external SSD for my mac.
The disk is advertised as offering speeds up to 2000MB/s and compatible with USB 3.2 gen2x2 (which allows speeds up to 2,500MB/s)
When the disk (which I got on ebay) arrived, it came with:
To clarify, SSD disk > cable > adaptor > port in mac
Those of you who think this is all fine, I challenge you to:
(a) state in theory the maximum speed achievable with the given setup and please submit your workings
(b) guess the speed I get in practice (at least, measured with the Blackmagic disk speed test)
(oh yeah, the speed of the mac's internal SSD measures at about 2,500 MBps so that should not be a limiting factor in itself)
The disk is advertised as offering speeds up to 2000MB/s and compatible with USB 3.2 gen2x2 (which allows speeds up to 2,500MB/s)
When the disk (which I got on ebay) arrived, it came with:
- A third party "USB3.1 type-C male to USB3.0 AM" cable
- A third party "USB3.1 Type CM to USB3.0 AF" adaptor
To clarify, SSD disk > cable > adaptor > port in mac
Those of you who think this is all fine, I challenge you to:
(a) state in theory the maximum speed achievable with the given setup and please submit your workings
(b) guess the speed I get in practice (at least, measured with the Blackmagic disk speed test)
(oh yeah, the speed of the mac's internal SSD measures at about 2,500 MBps so that should not be a limiting factor in itself)
nick
Pleomorphic Adenomas R us
I'm guessing a few hundred MBps (based off questions / conversations on the back up thread where I questioned the need for thunderbolt 4 etc when the limit is directed by the read/write speed of the external disk (and then got derailed by people with more knowledge saying that the structure of the files being written affects write speeds) )
teuchter
je suis teuchter
Maximum speed in theory though? Because it surely should be possible to say given the easy to understand and consistent USB protocol.
mauvais
on reddit or something
The USB4 port on the Mac is type C female. I don't understand where type A and adaptors come into it. Why don't you just use a C-C cable?
If it really is constrained by something USB3.0 then in theory 625MB/s but I think that something would probably have to be active, not just wiring.
If it really is constrained by something USB3.0 then in theory 625MB/s but I think that something would probably have to be active, not just wiring.
teuchter
je suis teuchter
Because at the moment I don't have one.
The drive arrived with an A-C cable and an adapter to change the A end into a C end.
The next question though, is whether it's worth me getting a C-C one and if so, what exactly should it be, to make sure it's not a limiting element? And then you disappear into a maze of USB variants, vague product specifications and doubts about what's compatible with what in which direction.
Saul Goodman
It's all good, man
At a guess, around 250MB/s
teuchter
je suis teuchter
Well, I've measured around 900MBps.
That's higher than USB3.0 should manage (625MBps) and the USB-A connectors that are part of the cable setup are labelled as USB3.0. Indeed the adapter says 5Gbps (=625MBps) on it.
So, is the cable over-achieving up to the limits of the disk's real world performance, or is it over-achieving but also limiting the disk that supposedly should achieve up to twice what I'm measuring? Who knows.
A USB3.2 gen2x2 cable ought to allow 2500MBps, and I could get one of those, and then in theory I could know the cable wasn't a limiting factor.
That's until I start trying to work out what the port on the mac is because Apple's specs tell me it "supports" USB3.1 gen 2 (elsewhere known as USB3.2 gen 2) at 10Gbps (=1250MBps) so it should allow somewhat more than the 900MBps I'm measuring. It doesn't tell me it supports the faster USB3 gen2x2 ... and yet, it's described as a USB4 port, and isn't USB supposed to be backwards compatible so if it's USB4 shouldn't it support USB3 gen2x2? Again... who knows.
Who knows, are (presumably) people with relatively specialist knowledge. But that's not what USB is supposed to be about, surely. It ought to be something that allows a moderately informed computer user to see quickly and clearly what's compatible with what.
Brainaddict
slight system overdrive
I hoped when we got the massively inconvenient switch to USB-C for phone charging (which is still a pain in the arse - I tried to borrow a charger from housemates recently and nope, they've all got older phones) that at least the sockets would be stronger. But no, I'm probably going to have to bin a Moto G6 with a couple of years more life left in it because the socket is fucked (and hard to replace). I think the charging socket has been a problem on every phone I've had. If you're going to change the standard, change it to something BETTER you fuckheads.
existentialist
Tired and unemotional
My USB-C equipped Android phone has been chargeable by the same cable for years, too
. Well, that's not strictly true, as I've replaced the cable a couple of times. But always with USB-C - I never felt any need to change.
maomao
普費斯
Are you hammering the cables in or something? I'm a heavy handed person, have a multitude of usb charged devices (several different kinds) and have never had this problem. And looking at the phone I'm on (pixel 4a) I'm not even sure how you would knacker it. The lip of the socket is not separate from the phone body and the tongue in the middle is far enough back from the lip to make it pretty hard to bend.
Brainaddict
slight system overdrive
Yes, I often use a lump hammer to get it in but I thought that would be fine.
I just put it in man, I'm not thinking about it. I don't think I should have to. One problem seems to be that for all these smaller usb fittings the plug can usually move around the socket - there's always some wiggle space. I think that stresses the interior tongue.
mauvais
on reddit or something
My anecdotal experience is that USB-C stands up better. I do Android development for a living and until this latest phone, where wireless debugging is a thing (so good), that meant plugging in a lot. Gradual port failure tends to be what kills off my phones although obsolescence and battery failure aren't far behind. Anyway the last phone was still working OK in that respect when I got rid. It ended up looser, as in easier to detach the cable, but it still worked.
souljacker
innit
The only problem I've had with USB-C is that pocket fluff gets in the port and stops it from charging. It's easily cleared out though.
Saul Goodman
It's all good, man
They did. USB-C is much better.
UnderOpenSky
baseline neural therapy
I got a hard disk enclosure this week. Its got a standard A connector on it, so the cable is the same both ends. I didn't actually know this was a thing.
teuchter
je suis teuchter
There's consistently an A type on one end and a B type on the other, except when there's not, so that it's always clear to the consumer what's going on. This way the consumer can always know when they have got a non-standard setup and be clear that they now need to be slightly confused. This avoids uncertainty. Of course now with the C type connectors, sometimes on both ends and sometimes on both, and an array of slightly different speed standards, consumer confusion can be further standardised to be constant in all situations. It's amazing work.
8ball
Decolonise colons!
Saul Goodman
It's all good, man
Some of mine don't fit until the fifth flip.
mauvais
on reddit or something
A-to-A is not in the spec because you could use such a cable to do bad things like short out components not designed to be connected.
I don't know why manufacturers insisted on doing it anyway.
Why is USB Type-A to USB Type-A never used?
I was wondering why almost all USB cables that exist are USB-A to (Micro-USB | USB-C | USB-B | etc.) Why was USB-A to USB-A not a popular thing? Is there a technical reason this cannot work?
mauvais
on reddit or something
Also, this:
This use of USB B sort of makes sense to me because it's good to have some physical differentiator between input and output USB ports. Whether this outweighs the disadvantages and overall weirdness, I don't know. It's not like the USB input to a monitor is swapped out very often so it's about as good as use for it as you get.
mauvais
on reddit or something
I'm not an expert on this, so treat with some caution.
This is what's going on in a USB C connector. For a start, it's only half as complicated as it looks. As you can see, it's symmetrical, which is why you can plug it in either way up.
Lilac is USB 2.0 and in theory you could have a USB C cable with just four pins (two USB 2.0, one +V and one GND) in one row wired up and it would do the job of USB 2.0 only. Double that to make it work either way up.
Connect up the blues and you have support for USB 3.x data, despite what the legend says.
The yellow (CC) is used to negotiate the specific mode for USB 3.x which determines the speed but that's just a channel, not a job of the cable itself.
So, if you have a cable (or cable chain including adapter etc) where everything is properly wired up, then the cable should be irrelevant to the speed outcome, and it's down to what the devices at either end negotiate.
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