Is it just me or is something wrong with USB?

T

tdemarco

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USB has now been around for a few years and proved itself to be the connection of choice for a wide range of devices. I must have connected twenty different peripherals over this period to one of more of our six Macs. I've come to believe that every new USB connection comes with problems. And a quick scan of this and the MacFixit forums shows many system problems that are USB related (E.G., the 16 page MacFixit tutorial on powerbook sleep problems and USB--16 pages!).
Just for starters, my desktop G4 configuration allows me five different kinds of USB connection (two built in ports, two on keyboard, two on the Cinema display, five on a D-Link powered hub, and four on an unpowered hub), and NO TWO OF THESE ARE ALIKE. Devices that work OK on one are invisible on another. Each new release of Apple software, changes the rules. For instance, 10.3 made connection of the keyboard via the display suddenly not work, and then 10.4 made connection of keyboard through the powered hub also not work. My scanner works nearly everywhere, but one of my two flash disks draws a bit more power than the other and so won't work on the keyboard nor will it work on the (powered) display port. It does work on the powered D-Link port, though sometimes it doesn't. My palm works on the powered hub, but the system forgets that it's there, and so I have to unplug it and plug it back in prior to synch.
Is it just me or is the design of USB inherently flawed?

Tom De
 
'Is it just me or is something wrong with USB?' - it is just you.

'USB has now been around for a few years and proved itself to be the connection of choice for a wide range of devices - no, USB was designed for non-data transfer devices, such as mouse'es (ok, mice), keyboard, printers, scanners, PDAs, etc. When one needs to handle data transfers - FireWire is the proven choice.

'... my desktop G4 configuration allows me five different kinds of USB connection' - no, there is only one standard USB connection. There are different USB speeds [1, 12, and 480 Mbits per second] and different USB protocols - depending the type of device [a hub verses a mouse, keyboard, etc.].

A hub, can be powered - and therefore must deliver 500mA at 5Vdc per port (connector), or non-powered - and therefore must deliver 100mA at 5Vdc per port (connector).

Compatiblity issues, typically, are those of the devices, and / or supplied drivers, not of USB itself. Naturally, Apple can cause some problems as well - depending on how the host USB processor is controlled via MacOS X.
Overall, however, MacOS X has itself rarely been the cause of USB issues.
 
tdemarco said:
USB has now been around for a few years and proved itself to be the connection of choice for a wide range of devices. ....

Tom De
Click to expand...
Yes, there is something wrong with USB. Apple has done a remarkable job to get the technology to work, but it is problematic. In his sarcastic way, barhar actually pointed out some of the problems with it. Some devices have to be powered; others do not. Each device uses the same connector even though there are multiples speeds. Not all vendors implement the complete USB standard. Despite claims to the contrary, some USB devices require proprietary drivers. As a Mac user, USB actually works fairly well for you. For real "fun," try it on Windows.
 
I try to keep it simple. I have _one_ powered USB-2 hub connected directly to my PowerBook. It's a seven port hub, which is enough for my devices. If I have to add something quickly, say a memory stick, I put it to the PowerBook's other direct USB-port or into the hub. It always works.

There are _some_ instances where one or the other device somehow kills the USB connection. Like when I accidentally connect that no-brand mouse which I theoretically _know_ doesn't work with Macs (it still sometimes happens). Then _none_ of the connected devices work anymore. I simply disconnect the hub, disconnect that mouse, reconnect the hub and all's fine. I think the problems start when you're using (actively using) too many hubs.
 
my keyboard ones are nearly useless. i always get a low power notice from them. i stuck a usb 2.0 5 port card in a pci slot, and then none of the usb ports in the mac worked properly, so i ripped it out. generally, it's a bit finnicky.
 
One kind of USB connection is particularly flakey, the one that allows a connected device to originate action. My scanner is an example: if I drive the scanner from my Mac, OSX can always find it, but the scanner has a scan button on it which is supposed to invoke the scan program, and that only works intermittently.

Palms are another example, since you originate a sync from the Palm instead of from the Mac. At least three quarters of the time, OSX does not detect the sync signal from the Palm. In these cases, I can always make it work by unplugging and replugging the USB connector (sigh), thus forcing OSX to re-learn that the device is there.

My own and others' inconsistent, sometimes maddening, results with USB connected devices makes me conclude that USB is architecturally flawed.
 
I've seen similar issues on Linux and PC's with USB. My theory (nothing more) is it comes down to the quality and completeness of the interrupt management within the driver code for the device in question. It's certainly not something easilly diagnosed and fixed in "user land". Sometimes the sequence devices are originally installed can effect this - install the devices that might generate the action (scanner, palm) 1st before other devices that are less demanding of interrupts.

Sorry I can't help you nail the problem down, I have never made any progress at really nailing it down myself. Haven't seen this on mac's yet because I am too new to macs ...
 
The sleep problems are not really USB's fault — that's all Mac OS X's fault, and it happens even with FireWire. The Mac OS has had this problem in one form or another since before USB even existed (yes, I'm talking about System 7 - OS 8).

barhar said:
'USB has now been around for a few years and proved itself to be the connection of choice for a wide range of devices - no, USB was designed for non-data transfer devices, such as mouse'es (ok, mice), keyboard, printers, scanners, PDAs, etc. When one needs to handle data transfers - FireWire is the proven choice.
Click to expand...
Hmm. I have to disagree. USB has proven itself as the dominant standard for virtually everything except digital video. I've certainly never seen a FireWire flash drive, and while FireWire thrives in the HD realm, USB2 is very common there, too. Heck, even Apple uses USB2 instead of FireWire for their HD iPods now. So yes, USB has proven itself as the connection of choice for a wide range of devices. Maybe it's not the best for everything (it's not), but hey, that was the original poster's point, wasn't it?
 
'FireWire flash drives' do exist; however, they are expensive - relative to USB flash drives.

One rather 'neat' usage is by Micromats 'TechTool Protege'.

'USB was designed for non-data transfer devices' was meant as 'as opposed to large volume data transfer'. For example, from data storage devices - hard disk drives, digital video cameras, etc..
USB 2.0 (at 480 Mbs) is generally slower than FireWire 400 (at 400 Mbs).

I have seen much discussions and comments, on the internet, as to why the latest iPods do not have FireWire. Even if Apple was to release a statement as to why, we may never know the real reason.
 
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