Comments on: USB 3.0 is a replacement, and not an extension of USB 2.0 http://billauer.co.il/blog/2015/12/usb-superspeed-parallel/ Anything I found worthy to write down. Sun, 29 Nov 2020 17:07:56 +0000 hourly 1 http://wordpress.org/?v=3.1.2 By: eli http://billauer.co.il/blog/2015/12/usb-superspeed-parallel/comment-page-1/#comment-1498 eli Fri, 24 Apr 2020 09:27:29 +0000 http://billauer.co.il/blog/?p=4875#comment-1498 Hello, The USB 3.0 spec is explicit about that all wiring, both USB 2.0 and USB 3.0 wires are connected between each device and host / hub, so you will definitely be violating the spec by letting only the SSTX / SSRX wires through for one of the devices. Having said that, I can tell from personal experience that if you connect only the SSTX / SSRX wires, it works perfectly well. You should also have the GND connected to prevent excessive DC voltages. However since you're breaking the rules, and is not in control of the device, I can see a possibility that the device refuses to play ball with the 3.0-only wiring. Not very expected, but yet possible. If it's very specific hardware involved, I would get myself a USB 3.0 extension cable, and cut off the non-3.0 wires, and see what happens when the device is behind it. Just be sure to test that it connects as USB 3.0 before doing the cuts. Some extension cables are junk. Hello,

The USB 3.0 spec is explicit about that all wiring, both USB 2.0 and USB 3.0 wires are connected between each device and host / hub, so you will definitely be violating the spec by letting only the SSTX / SSRX wires through for one of the devices.

Having said that, I can tell from personal experience that if you connect only the SSTX / SSRX wires, it works perfectly well. You should also have the GND connected to prevent excessive DC voltages.

However since you’re breaking the rules, and is not in control of the device, I can see a possibility that the device refuses to play ball with the 3.0-only wiring. Not very expected, but yet possible.

If it’s very specific hardware involved, I would get myself a USB 3.0 extension cable, and cut off the non-3.0 wires, and see what happens when the device is behind it. Just be sure to test that it connects as USB 3.0 before doing the cuts. Some extension cables are junk.

]]> By: Troy http://billauer.co.il/blog/2015/12/usb-superspeed-parallel/comment-page-1/#comment-1497 Troy Thu, 23 Apr 2020 17:29:46 +0000 http://billauer.co.il/blog/?p=4875#comment-1497 I was thinking about a project I am working on and right now I have a USB 2.0 (even though its a USB 3.0 port) connected to a switch and then connected to a USB 3.0 Micro B connector (even though I am only getting the USB 2.0 connection). The switch only has 4 positions and this is why I didn't use the USB 3.0. This connection is between a router and a hard drive and the switch is used to alternate between loading data to the drive in one position and the other position is for direct connection between the router and the drive. So after reading this I am thinking I can eliminate the switch. I can have the USB 2.0 to a port for loading data to the drive and the USB 3.0 between the router and the drive for normal operation. Does this make sense? I can send a wiring diagram to you. Does the USB 3.0 need power along with the SSTX pair, SSRC pair, and ground? I was thinking about a project I am working on and right now I have a USB 2.0 (even though its a USB 3.0 port) connected to a switch and then connected to a USB 3.0 Micro B connector (even though I am only getting the USB 2.0 connection). The switch only has 4 positions and this is why I didn’t use the USB 3.0. This connection is between a router and a hard drive and the switch is used to alternate between loading data to the drive in one position and the other position is for direct connection between the router and the drive. So after reading this I am thinking I can eliminate the switch. I can have the USB 2.0 to a port for loading data to the drive and the USB 3.0 between the router and the drive for normal operation. Does this make sense? I can send a wiring diagram to you. Does the USB 3.0 need power along with the SSTX pair, SSRC pair, and ground?

]]> By: eli http://billauer.co.il/blog/2015/12/usb-superspeed-parallel/comment-page-1/#comment-1384 eli Mon, 10 Dec 2018 05:38:23 +0000 http://billauer.co.il/blog/?p=4875#comment-1384 Indeed: If you connect only USB 2.0 devices to a USB 3.0 hub, it will perform exactly the same as a USB 2.0 hub. The USB 3.0 lanes will be detected by the host, but will carry no traffic. Indeed: If you connect only USB 2.0 devices to a USB 3.0 hub, it will perform exactly the same as a USB 2.0 hub. The USB 3.0 lanes will be detected by the host, but will carry no traffic.

]]> By: Bob http://billauer.co.il/blog/2015/12/usb-superspeed-parallel/comment-page-1/#comment-1383 Bob Mon, 10 Dec 2018 04:55:32 +0000 http://billauer.co.il/blog/?p=4875#comment-1383 Thank you for helpful information, I have a question in this regard, You said by using a USB3 hub that is connected, let's say to 4 USB2, it does not mean that the host is working on 5Gb/s while the ports are working on 500kb/s? right? If 4xUSB2 devices are connected to the USB3 hub (by leaving SSRX and SSTX float) you mean that the USB3 host plug works at USB2 speed? Thank you for helpful information, I have a question in this regard, You said by using a USB3 hub that is connected, let’s say to 4 USB2, it does not mean that the host is working on 5Gb/s while the ports are working on 500kb/s? right? If 4xUSB2 devices are connected to the USB3 hub (by leaving SSRX and SSTX float) you mean that the USB3 host plug works at USB2 speed?

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