USB Ports - Are they 2.0 or 3.0?

Good morning all.

I have looked at just about every discussion on the community site and cannot find a definitive answer. I've seen discussions on what the second USB port can be used for, USB hard drives that work with the Tablo, but I cannot determine if the USB controller in the 4-Tuner version of the Tablo is a USB 2.0 or 3.0.

I am wondering because there will be nights when I have 4 shows recording and possibly 4 recorded streams playing via multiple Roku 3's. That's a lot of IO on the HDD.

USB 2.0 should have a theoretical limit of ~35MB/s (480 Mbps) and USB 3.0 at ~640MB/s (5 Gbps).... with the hard drive being limited to ~125MB/s. If 1080p live video can be written fairly easily at ~4.5MB/s, a USB 3.0 controller should not have any issues handling the IO.

BTW - I have a 1TB WD Passport (USB 3.0) and am about to replace it with a 2TB WD Elements (USB 3.0) - Model WDBU6Y0020BBK-05

Any ideas... 2.0 or 3.0?

Thanks!

Not a Tablo employee or expert here but I read in a response from one of the Tablo users (TabloSupport or TableHQ) that they are USB 2.0.  I don’t recall which discussion it was in but it was in response to someone asking if using a spare SSD would help performance.  The Tablo response was that it would not and that “we don’t need the speed” and “that’s why we use USB 2.0 ports to save cost”.  Quotes are my paraphrasing.  Hope this helps!

Thanks for the reply!

I was afraid they were 2.0 ports. I will have to set up that scenario in the next few days (4 programs recording, 4 playing) and see what happens.

@snzkickin The USB ports are USB 2.0


Because the Tablo transcodes, the most one stream will actually send to the disk is 10Mbps. So, 10 x 4 (on the quad) = 40Mbps - well within USB 2.0’s limits :slight_smile:
@snzkickin The USB ports are USB 2.0 Because the Tablo transcodes, the most one stream will actually send to the disk is 10Mbps. So, 10 x 4 (on the quad) = 40Mbps - well within USB 2.0's limits :)

@TabloSupport, and, assuming the most a video will take to read from the disk is 10 Mbps… then, to support your feature set:


* 4 recordings
* 6 device playbacks

(10 Mbps x 4 recordings) + (10 Mbps x 6 devices) == 100 Mbps

USB 2.0 has a real-world limit of 280 Mb/s – it seems you are still way under that.

What worries me, and I’m sure you got a handle on this, is if I send one big copy operation to my USB stick (on my PC), then it goes pretty fast. If I send that same amount of data to the USB stick in several parallel copy operations it goes really slow (much longer than the single operation). This could simply be the nature of the memory in USB sticks. So many variables there, though, so you can feel free to ignore me.

@snzkickin - How is your Passport right now? We’ve seen this line have disconnect issues.



@cedarrapidsboy - This is exactly why we don’t support USB sticks! :slight_smile:
@snzkickin - How is your Passport right now? We've seen this line have disconnect issues.

@cedarrapidsboy - This is exactly why we don’t support USB sticks! :slight_smile:

Thanks for the reply!

The Passport seemed to be fine from what I can tell except for an occasional ‘cannot load’ or ‘unable to play’ message when I went to view a recorded TV show. I would back out one screen, click it again, and it would play fine.

I did replace it with the 2TB WD Elements drive and I will see if that has the same behavior.

@snzkickin Keep us posted!