USB hubs reduce speed of audio interface?

[slirak]

I've tried a Belkin and an HP hub and both added 2 ms of latency to my Apogee One USB interface. It didn't matter if nothing else was connected or if I powered the hubs. This was on a late 2008 unibody MBP Core2Duo@2.4GHz and 4GB RAM.

Interestingly, Live picked up on the added latency automatically.

wow, cool info. 2ms, I'm surprised.

did a quick google, it might be a purposeful delay when using Isochronous USB transfers, but 2ms is a loooong time in computer terms. maybe it's related to a buffer size.

Yeah, 2 ms is a lot, especially considering that I'm at ~7 ms w/o a hub. That's almost a 30% increase.

It kept at 2 ms even if I turned up the buffer size in Live though and it was the exact same amount (like 2.12 or something) down to the second decimal with both hubs. Both those facts sure sound like a fixed buffer to me. Could be the hubs or OS X adding it for safety I suppose. BTW, I forgot to mention that this was on OS X 10.5.x. (x = 6, 7 or 8 ). Haven't upgraded to Snow Leopard yet.

[veedid]

I don't care USB hubs reduce the speed.

[Tone Deft]

I don't care USB hubs reduce the speed.

NO THEY DON'T

[vicz]

I don't care USB hubs reduce the speed.

Only if you plug a USB 1.1 hub into a USB 2.0 port

[Fizmarble]

I have a M-audio Keystation pro 88 connected through usb. It has latency creep. It gets worse the longer it's plugged in, and it was worse when I had it through a usb hub. But even without it, it still creeps and gets more delay the longer it's plugged in.

[adam8290]

There are also some 13-port hubs out there for around $40. I've picked up one but have not had time to assure that the little glitches I was encountering were from the hub. For now I am relying on a Belkin 7 port hub, but I end up short by just a few ports. I'm on an Imac. I've asked about this question before in Abe Forums and gotten some pretty good answers, so you might search on adam8290 & hub.

I send my interface directly into my imac FW400. I also send my external hard drive (with my live library on it) through the imac's FW800 port. The Waves Ilok key gets a port on the imac. The APC40 gets one since it won't work without a direct connection. Finally, the Belkin 7-port gets the last one. Oh, there's one slow USS port on the keyboard that I'm actually not sure what it goes into just now.

--Adam

[Donnie]

I reccomend never running your audio interface through a hub. Its just not a good idea, even if works for some.

[contakt321]

I reccomend never running your audio interface through a hub. Its just not a good idea, even if works for some.

Why?

Not being jerky, just trying to get some empirical evidence in here as to why it's not advised.

[emef]

for my own peace of mind i run my audio interface off one dedicated usb port and everything else through my powered usb hub

[Donnie]

I reccomend never running your audio interface through a hub. Its just not a good idea, even if works for some.

Why?

Not being jerky, just trying to get some empirical evidence in here as to why it's not advised.

Its a fair question. You are basically making your most important and resource intensive device (audio interface) depend on an intermediary device, and a device as fickle as a usb hub no less! Depending on the hub it could mean latency, instability, random disconnects, device failure, shit...the list goes on. In theory everything should work great, but there are too many variations involved to take that risk. When it comes down to it your audio interface is the LAST thing you want to go down, so you are better off giving it a dedicated connection and dedicated power whenever possible.

[Fizmarble]

The usb ports on your computer are pretty much a usb hub as it is on most cases. You see two or four usb ports on the side of your laptop, they are basically an internal hub.

[Donnie]

The usb ports on your computer are pretty much a usb hub as it is on most cases. You see two or four usb ports on the side of your laptop, they are basically an internal hub.

Sure, but isnt that just more reason not to add more hubs to the chain. Every step is just another chance for your most important device to have a problem

Not to mention your laptops usb have been integrated specifically for that device, and tested with that device. Your usb hub is a completely different story.

Like I said...theoretically...

[Fizmarble]

The usb ports on your computer are pretty much a usb hub as it is on most cases. You see two or four usb ports on the side of your laptop, they are basically an internal hub.

Sure, but isnt that just more reason not to add more hubs to the chain. Every step is just another chance for your most important device to have a problem

Not to mention your laptops usb have been integrated specifically for that device, and tested with that device. Your usb hub is a completely different story.

Like I said...theoretically...

USB 2.0 is a spec, so each device doesn't need to be tested. It's built to a spec that's tested already. I think usb hubs have a stigma attached that isn't rational. A powered usb hub should be just as good, if not better than the shared hub built into the motherboard. USB is USB, power is power. They should equal each other theoretically.

[Donnie]

USB 2.0 is a spec, so each device doesn't need to be tested. It's built to a spec that's tested already. I think usb hubs have a stigma attached that isn't rational. A powered usb hub should be just as good, if not better than the shared hub built into the motherboard. USB is USB, power is power. They should equal each other theoretically.

No, its based on experience. USB hubs are not known for there consistancy and reliability.

So using this logic all USB hubs are built and tested the same way using the same components? Obviously no. Sure the USB standard is just that, but that has nothing to do with what I am saying. I am saying your laptops device has been tested with the laptop, to work with your laptop. This is basic design/manufacturing process.

Hey, run you audio interface through a hub, it doesnt matter to me. Either way you slice it it WILL cause problems for some people, often unexpectingly. Beyond that, pointless arguement. Everything should work in theory, but theory does not always equal reality.

[vicz]

The OP question was whether a hub would slow down the audio interface, and it won't. There are other reasons why it may not be a good idea - reliability of hubs, software glitches, more cables etc to get pulled out or fail while you are working.