Question about transferring recordings from old HDD to new HDD via PC

[Black Hole]

Well, USB started at 1.5Mb/s (too slow for anything much) then moved on to USB2 (480Mb/s). The new kid on the block, USB3 does 5Gb/s so long as both ends support it (more wires in the connector, but falls back to USB2), and now USB4 is in the starting gate (30Gb/s) using a totally different connector. Obviously, the HDR-FOX has USB2.

The next question is whether there is anything in the implementation which might give one port a performance advantage over the other. If there were more ports than two, I might say that was possible - eg two ports sharing one data path and another one on a different data path, but clearly that's not likely with only two ports... it seems unlikely the designers would share one USB port with (eg) the network interface rather than sharing the port with the other USB port.

What it boils down to is that I have no reason to expect different data rate capabilities between the two USB ports, subject to carefully conducted trials.

 

[MikeSh]

OK. I understand that.
I know that ports of the same type (eg. USB 2) can have different power capabilities which made me wonder if there was anything else that could be different. If there was then I could be fairly sure it would trip me up

From what you've said I presume no-one has found any difference in speed, etc, between the two Humax ports.

 

[Black Hole]

can have different power capabilities

The USB spec requires a specific 5V current capability from each and every properly compliant port, but this is subject to abuse, and the spec is only a lower limit. Some chargers (eg Apple) are designed to negotiate higher voltages if the connected device can take it, to increase the power that can be delivered (and therefore the rate of charge) without increasing the current beyond the safe limit for the cable, but those are specifically chargers and they only output 5V unless there is a negotiation.

The main difference to be aware of is that a USB3 port has a higher current specification.

The main point to note is that the 480Mb/s spec for USB2 is neither a limit nor an expectation. The characteristics of the connector, cable, and the AC characteristics of the signalling system, impose a physical limit on the data rate (which may well be better than 480Mb/s), but the implementation of the electronics and how busy the rest of the system is will almost certainly reduce the actual data rate substantially.

From what you've said I presume no-one has found any difference in speed, etc, between the two Humax ports.

I haven't, but I have not conducted detailed trials. A job for you? To be valid, you would need to ensure conditions were identical between testing the front port and the rear port (preferably with the box doing nothing else at the time - Maintenance Mode?).

 

[Trev]

For transfers using a USB to SATA link from FOX to/from HDD is there any difference using the front or back USB port on the box?

All this time wasting speculation. Why not just try it and report back

 

[prpr]

All this time wasting speculation. Why not just try it and report back

Quite. I had a really nasty email from a (now ex, thankfully) person in another part of our organisation when I light-heartedly told him to 'just try it' instead of asking endless questions about something, and he was bugging everyone elsewhere too.

 

[Black Hole]

Yeah, I recall somebody who wanted all the i's dotted and t's crossed when it would have been quite apparent what to do if he actually did it instead of asking questions that really didn't need answering.

 

[/df]

To waste some more time, the BCM7405 chip at the heart of the HD/Rs offers 3 USB ports:

The USB module consists of the host controller with root hub capability, a device controller, and two integrated transceivers with two ports. The host controller is USB 2.0 compliant, and the transceiver is able to operate at a transfer rate of 480 Mbps. The device controller communicates at a rate of 480 Mbps.

A third USB 2.0 host/client port is available and is independent and private with respect to the USB 2.0 channels.

The BCM7405's digital audio output pin can be biased to 3.3V instead of 0V to force the third port into client mode. Presumably this happens at start-up when the audio output is not being used. The test schematic shows a jumper to set the bias voltage with 10x larger resistors pulling up/down than that to the SPDIF output stage.

The OS has found or been configured with devices usb1 and usb2 using the EHCI driver, and usb3 and usb4 using the OHCI (USB1.1) driver. If those correspond to ports 1 and 2 in USB2.0 and USB1.1 respectively, presumably the 3rd port has been disabled in the configuration, and if so it's likely that the front and rear ports are identical apart from cabling.

 

[MikeSh]

All this time wasting speculation. Why not just try it and report back

Quite.

Because where the box lives makes accessing the rear USB port difficult ... and it has the WiFi dongle in it.

Since these boxes have been in the wild 10 years or so it seemed probable this knowledge was around. I just asked a simple question so I could decide if I would be better going to the trouble of accessing the rear port or not.

If getting answers here these days is going to be a trial by fire every time then these boxes are going to end up in the recycling a lot sooner than they could

Thanks anyway to BH and latterly /df for responding sensibly.

 

[MikeSh]

New Seagate Pipeline 2TB installed and all files (slowly) transferred

While doing the t'fers I had the old disc sat nearby, with one end propped up to let a bit of air under, and it was still running pretty warm.
I notice also that the box (with the new disc) is reporting a lower temperature than before. It has 44% set for the fan and I think it used to run about 46-47°C but now runs about 40-42.
I did brush the fan off while it was out, but there was hardly anything on it, so I doubt that's the main cause. I assume the newer discs just burn less power.