USB 3.0 and an extension cable - Page 1
Forum section: electronics / general

author: Srbel
author_rank: Frequent Contributor
timestamp: August 17, 2016, 09:23:56 am
content: I have an external HDD with USB 3.0 support. With the cable that came with the HDD, when I plug it into a USB 3.0 port on my computer, it works as USB 3.0. But, when I plug that cable into an USB 3.0 extension cable, and then into a USB 3.0 port, then it only works like USB 2.0. And Windows gives a message: "This device can perform faster if plugged in USB 3.0...".Is the total length of cables the problem, even though they are USB 3.0 cables?HDD:http://www.transcend-info.com/Products/No-324Cable (only mine is 1,8 m):http://www.mikroprinc.com/proizvodi/elektromehanicke-komponente/kablovi/gotovi-kablovi/kablovi-usb/k-usb-3.0-am-usb-af-3m/index.php

author: Kilrah
author_rank: Unknown
timestamp: August 17, 2016, 11:27:49 am
content: Max length for USB3 seems to be about 3m without active repeaters, so if your extension is 3m plus the HDD's own cable plus a set of connectors it might indeed not work reliably.

author: Srbel
author_rank: Frequent Contributor
timestamp: August 17, 2016, 11:40:03 am
content: It is less than about 2,3 m total.Extension cable is 1,8 m, and the HDD cable is short (see picture):https://www.goldfries.com/images/hwreviews/2016/transcend25h3/25H3_02.jpg

author: MosherIV
author_rank: Super Contributor
timestamp: August 17, 2016, 12:13:44 pm
content: USB extensions barely work for USB2.I would not expect USB3 to work with any extension, think about the data bandwidth required.USB3 is a highly balanced transmission network. Any deviation from the correct parameters will seriously degrade the data signal.

author: Srbel
author_rank: Frequent Contributor
timestamp: August 17, 2016, 12:30:09 pm
content: But this HDD is only doing like 90 MB/s or so max.

author: TiN
author_rank: Super Contributor
timestamp: August 17, 2016, 01:11:48 pm
content: It does not matter what actual device speed, as USB link trains at interface speed. And if it does not train, controller drops USB3 SS link and works on USB 2.0 instead. Exactly what you seeing there.

author: rdl
author_rank: Super Contributor
timestamp: August 17, 2016, 01:55:19 pm
content: Maybe just get a longer cable instead?

author: Srbel
author_rank: Frequent Contributor
timestamp: August 18, 2016, 06:20:41 am
content: Longer? O.o

author: orin
author_rank: Frequent Contributor
timestamp: August 18, 2016, 07:36:27 am
content: The extension cable could be mis-wired and have the USB3 TX/RX pairs swapped... you get that error - the OS reports the device can perform faster if plugged into a USB 3 port. At work, we had many cables that had the pairs swapped in the molded blue plug. It didn't help that each pair was blue/white and that they were individually shielded with foil... on one pair, the foil was very pale blue and the other was very pale green. Not surprising that sometimes they got swapped in manufacture.Of course, it could just be that given the quality of the cables, they are simply too long. Even for USB 2 cables, there is a lot of junk out there with price not really being an indicator of quality.

author: Srbel
author_rank: Frequent Contributor
timestamp: August 18, 2016, 08:35:00 am
content: Quote from: blueskull on August 18, 2016, 07:11:09 amI meant, when it works in USB 3.0 mode, I get something like that. But with an extension cable, I only get UBS 2.0 speeds, and that message.

author: fubar.gr
author_rank: Unknown
timestamp: August 18, 2016, 09:04:35 am
content: USB3 pushes the limits of transmission speed over twisted pairs.Therefore it relies heavily on the quality of the cable.

author: sync
author_rank: Frequent Contributor
timestamp: August 18, 2016, 09:44:05 am
content: Quote from: MosherIV on August 17, 2016, 12:13:44 pmDepends. Two USB3 extension cables 1.8m + 3m in series. One USB3 to SATA adapter works fine. Reading at 195MB/s sustained without errors. Another USB3 to SATA adapter gives massive amount of errors. Completely unusable.

author: Srbel
author_rank: Frequent Contributor
timestamp: August 18, 2016, 09:55:32 am
content: So, it could be swapped data lines in cable, bad cable (pairs not twisted enough times?), bad connection with USB connectors or a controller issue (in the HDD case).

author: mariush
author_rank: Super Contributor
timestamp: August 18, 2016, 05:28:14 pm
content: Here's a cable that will work, and it's 10 meters long :https://www.amazon.com/Optical-Cables-Corning-Cable-Meter/dp/B00JOJRF6K/ref=sr_1_1?ie=UTF8&qid=1471541039&sr=8-1&keywords=usb+3+fiberIt's expensive though, $100+ but it uses optical fiber instead of data wires, and regular wires for power transmission.

author: rdl
author_rank: Super Contributor
timestamp: August 18, 2016, 07:24:01 pm
content: I wasn't kidding, just get a longer cable. For a high speed connection like USB 3 I wouldn't even consider stringing multiple cables together. A decent quality single piece 1 meter/ 3 ft. cable is less than $10 here. Surely they sell similar ones where you live?http://www.newegg.com/Product/Product.aspx?Item=9SIA6ZP3KE2459

author: Zbig
author_rank: Frequent Contributor
timestamp: August 18, 2016, 07:46:48 pm
content: 90MB/s over a single serial link to/from magnetic storage medium is "only" now? Kids these days...

author: rrinker
author_rank: Super Contributor
timestamp: August 18, 2016, 08:31:59 pm
content: It is also potentially a power issue. I have a old USB 2.0 external drive, it came with a very short cable. It does not work reliably if I use a longer cable. I have another external box that I mounted an old laptop HDD in (when I swapped for an SSD), and it too came with a very short cable. I can use the HDD's cable on either device, but the external box's cable will not work on the HDD.

author: wraper
author_rank: Unknown
timestamp: August 18, 2016, 08:34:43 pm
content: Quote from: rrinker on August 18, 2016, 08:31:59 pmThen your cables most likely are crap with very thin power wires and that causes large voltage drop.

author: rrinker
author_rank: Super Contributor
timestamp: August 18, 2016, 08:49:50 pm
content: I dunno, they seem to power Arduinos with a bunch of LEDs and stuff just fine. ANd work with other peripherals. The two short ones that came with the drives seem exactly the same, but one works, the other does not.And I'm not talking trying to run more than 3 meters here, this is more like replacing a 1/4 meter cable with one that's maybe a meter.

author: C
author_rank: Super Contributor
timestamp: August 18, 2016, 11:18:12 pm
content: The simple fix for needing longer cable for USB 2.0 is a powered hub.Same should be true for USB 3.0The powered hub should retransmit the signals.

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 19, 2016, 03:18:50 am
content: A USB 3.0 hub isn't even particularly expensive nowadays.

author: Srbel
author_rank: Frequent Contributor
timestamp: August 19, 2016, 06:39:43 am
content: I just use an extension cable from the back of the desktop computer case, over the top, and there is where it sits. I only do this so I can have USB port on the front of the case.

author: Zbig
author_rank: Frequent Contributor
timestamp: August 19, 2016, 01:41:10 pm
content: Quote from: Srbel on August 19, 2016, 06:39:43 amYes, you do this and it doesn't work. You got several valid suggestions how to make it work. Passive USB extension cables are a violation of the standard and were specifically declared a firm no-no in the USB papers since the very beginning of the standard, if I'm not mistaken. They are not guaranteed to work, they just might if you're lucky. What else do you expect from us?

author: bicc1306
author_rank: Contributor
timestamp: August 19, 2016, 01:57:03 pm
content: I think the most of us make mistake when take a 10 foot cord that came with device and then purchase a 10 foot extension to make a cable 20 feet.

author: rdl
author_rank: Super Contributor
timestamp: August 19, 2016, 03:23:19 pm
content: Quote from: Srbel on August 19, 2016, 06:39:43 amI use this:http://www.newegg.com/Product/Product.aspx?Item=N82E16811999246All it does is provide front panel connections to a USB 3.0 port on the motherboard. You need to have a motherboard with USB 3.0 built in. If you're using some kind of add-in card it won't work. The box is empty. There are no electronics inside. It's just something to hold the front panel in place.

author: wraper
author_rank: Unknown
timestamp: August 19, 2016, 03:29:18 pm
content: Quote from: rrinker on August 18, 2016, 08:49:50 pmYour Arduino with bunch of leds does not consume even fifth part of that current. And other peripherals barely anything at all. Also if you are using front panel USB of the desktop PC, then expect at least half a meter of additional cable, likely crappy one. Iv'e seen a PC case from supposedly respectable brand which had just ribbon cables to front panel USB, no any shielding or thicker wires for power at all.

author: rrinker
author_rank: Super Contributor
timestamp: August 19, 2016, 07:05:37 pm
content: From my laptop, not desktop PC. And the port DOES supply enough power to charge my phone.I've put together enough stuff attached to Arduinos now that I need to use an external supply, the USB can't keep up (or rather, the regulator on the Nano can't supply enough power_, though total draw is pretty low, I can set the current limit to 50ma on my bench supply and it doesn't flip into constant current mode.It's a known issue with this particular model WD external drive. They do something strange - I originally bought it as a cheap way to get an bigger hard drive in my laptop, since most of these thing are standard laptop SATA drives plugged into an adapter board, but I pulled this apart and they integrated the USB on the drive electronics so I couldn't do what I wanted to with it. I've since gone SSD, and since we've gone Office 365 with OneDrive I've dumped all the stuff I used to have to keep in the external drive and now I can get to it from any computer I want, without carrying the external drive around. Now all I use it for is to throw some movies on when I go away on business trips. If I was that curious I'd get one of those USB voltage and current monitors, or build one, just to see what this drive does that the other one does not.

author: Kilrah
author_rank: Unknown
timestamp: August 19, 2016, 07:18:04 pm
content: Quote from: rrinker on August 19, 2016, 07:05:37 pmI came across one of those recently, friend had a failing drive and as I've had multiple instances where it was actually the USB-SATA adapter that failed but the drive was fine I opened the thing to take the drive out and put it in a cradle... but no. The bastards

author: Srbel
author_rank: Frequent Contributor
timestamp: August 19, 2016, 07:19:50 pm
content: Quote from: rdl on August 19, 2016, 03:23:19 pmThis is literary the same as an extension cable.And yes, my motherboard has USB 3.0.