Only able to connect 42 USB devices

Jacksleo · 25 Mar 2015

I am trying to build a setup to read a lot of smart cards.

I have a dedicated USB controller card with 4 USB port which each should be able to run up to the 128 USB devices.

On 1 powered USB hub with 10 ports I have connected 6 USB smart card readers and 3 other powered USB
hubs with each 10 USB smart card readers so a total of 36 smart card readers.

This connected gives a total of 42 USB devices (36 readers, 4 hubs, 1 mice, 1 keyboard).

We have checked the power setup and the powered USBs is providing fine.

It runs without any problems at all on any of the USB controller ports.

Connecting one more USB device of any kind results in it not loading. A reboot with the unit connected gives a random USB unit failing but the removing any other will bring that one up.

So it seems like somewhere theres a blocker at 42 USB devices any who know if there is such a thing in windows?

Layback Bear · 25 Mar 2015

This post is a joke right.

Jacksleo · 25 Mar 2015

Ofc its not a joke.

Have around 250 smart cards to be hosted 24/7 but sadly they have to be on windows machines.

If I can only get the 36 I need 7 machines running them and I was only counting to have 2.

Lady Fitzgerald · 25 Mar 2015

Forgive my curiosity but why do you need to access so many cards at once?

One possible bottleneck may be the USB controller card itself. If the card is running off just one PCI-e lane (which means the vast majority of cards), then each USB port on the card will be running at no more than 1.25GB of bandwidth when all ports are being drawn on. Also, even when using powered hubs, you can daisy chain only so many before getting shut down.

Also, many of us don't speak textese and I, for one, do not appreciate having to look up texting shortcuts like ofc. If what you are saying is so vulgar as to require text abbreviation to "get away" with posting, mayhap you shouldn't use the expression at all. Jack's asking if your request was a joke is understandable considering you are a brand new poster and it is extremely unusual for someone to want to process so many cards at once (I've never seen it before) so there was no need for disguised profanity.

Jacksleo · 25 Mar 2015

I have that many smart cards I need to keep online.

The daisy max should be 128 on each main port and I also hit 42 if I use the standard USB instead of the installed card.

There is no active data transfer when Im connecting more readers so it should not block up on bandwith.

Its not a joke proberly gives you the meaning then. Never heard any making that kind of jokes and spending time to register to make them.

If there were answers or any experience on mass USB usage or of the 128 max USB that is said to be the max I wouldn't have to post but could use those answers. I doesn't get the point of the rest of your post so I guess this answer will have to do.

Lady Fitzgerald · 25 Mar 2015

Jacksleo said:

I have that many smart cards I need to keep online...

That doesn't really tell us anything. Why do you have so many and what are you doing with them?

Jacksleo said:

...Its not a joke proberly gives you the meaning then. Never heard any making that kind of jokes and spending time to register to make them...

We have, hence the question.

Jacksleo · 25 Mar 2015

Its digital tachograph company smart cards that you sync up with a truck drivers tachograph smart card to transfer the statutory truck driver informations.

Lady Fitzgerald · 25 Mar 2015

For something on this large of a commercial scale, you probably should hire an IT professional to set up a system for you to avoid possible legal issues.

Layback Bear · 25 Mar 2015

There has got to be a better way of doing this project other than this.

from post #1

This connected gives a total of 42 USB devices (36 readers, 4 hubs, 1 mice, 1 keyboard).

I understand that many trucking companies monitor many things from a truck on the road.
They surly don't have a bunch of usb devices hanging all over off of hubs and usb ports.

Jacksleo I would suggest you do some research on how other trucking companies do such things.

Indianatone · 25 Mar 2015

Technically you'll also be limited to a maximum of 24 drives per computer given that Windows is on the C drive and the CD/DVD is on D drive. That leaves you 24 drive letters so the machine can see and use the USB Drives. So by that issue alone you are going to need 11 PC's absolute minimum but I would suspect that it would be rife with problems. Not something that is a good idea, probably need more PC's that that for reliability. I would suggest a maximum of 10 USB drives per machine and that frankly would be pushing it.