USB Hub Wierdness

[Minwah]

I have a control panel which has an analog joystick interfaced with an AKI, and a spinner & trackball interfaced with an OptiPac.  The AKI and Opti-Pac are plugged into a 2 port USB hub, so I only need 1 cable.  This works great...

Thing is I just bought a USB 2.0 hub (also says compatible with USB1.1 low speed devices), and mounted it near the fron door of my cab for easy access for control panel leads and my portable USB HDD.  This also seemed to work ok...until I started playing MAME.

For some bizarre reason when my analog control panel is plugged into the hub, and I play spinner (& presumably trackball) games, the framerate drops like a brick, but only when I move the spinner.  For instance I load up Arkanoid, and display the FPS...it is at a solid 60/60, until I move the spinner.  Then it will drop to like 30-45 fps.  If I continuously spin the spinner, the framerate drops to 3 fps.  When I stop spinning it gradually goes back up to 60fps.  WTF!!  

So far I can only put it down to the USB hub being crap...can anyone shed any more light?

[2600]

Well this may be a rant because of my experience with USB.  (I'm developing USB boards for work and we use a mass amount of USB devices, like 125 per PC.  The max is 127)

Anyone here can correct me if I am wrong.  USB is CPU intensive, no real DMA and the CPU schedules everything.  USB2 is even more complicated, in that it schedules USB2, and for USB 1(low and full speed devices) it schedules the USB 1 inside of a USB 2 transaction (They call this transaction translator).  Some hubs do this for each port(Multiple Transaction Translators).

That being said, I doubt it is your hub as they all use pretty much use the same chip and are pretty identical.  I don't know the spec of your machine, but as a quick test here is what I would do.  Assuming everything is good power wise, disable High speed USB in your BIOS.  This takes one second and basically turns off the EHCI(USB2) controller.  It will make your hub show up as a 1.1 hub and should be less CPU intensive.  Let me know what numbers you get.  Also, what OS are you using?  For USB 2, if you are using windows I've had better experience with XP, 2000's USB2 stack in my opinion isn't as good.

[Minwah]

Well this may be a rant because of my experience with USB.  (I'm developing USB boards for work and we use a mass amount of USB devices, like 125 per PC.  The max is 127)

Anyone here can correct me if I am wrong.  USB is CPU intensive, no real DMA and the CPU schedules everything.  USB2 is even more complicated, in that it schedules USB2, and for USB 1(low and full speed devices) it schedules the USB 1 inside of a USB 2 transaction (They call this transaction translator).  Some hubs do this for each port(Multiple Transaction Translators).

That being said, I doubt it is your hub as they all use pretty much use the same chip and are pretty identical.  I don't know the spec of your machine, but as a quick test here is what I would do.  Assuming everything is good power wise, disable High speed USB in your BIOS.  This takes one second and basically turns off the EHCI(USB2) controller.  It will make your hub show up as a 1.1 hub and should be less CPU intensive.  Let me know what numbers you get.  Also, what OS are you using?  For USB 2, if you are using windows I've had better experience with XP, 2000's USB2 stack in my opinion isn't as good.

I'm using XP (P4 2.8ghz).  My motherboard has 4 USB2 sockets, which work perfectly...I only get the problem when I use the hub.  So I am positive the hub is the problem...why I do not know  

[2600]

But you are only using USB2 when the hub is attached.  When your devices are plugged directly into your motherboard they are 1.1 devices and attached to your 1.1 controller.  (Each ECHI (USB2) controller has 3 or so USB 1.1 controller's builtin(UHCI or OHCI).  So you are only using USB 2 when the hub is plugged it.  If you don't believe me or want a sanity check look in Device Manager, change the view so you can view by connection, and you will see which controller they are attached to.

Unless you have some need for USB2(hard drive, wireless), take the one second and try what I said.  If it works, then you can save yourself some time and not have to worry about anything else.  If I'm wrong, you waisted 1 minute of your life.

[Minwah]

I tried it and yes you are totally right, it works fine with USB2 disabled - thanks for taking the time to explain that to me

Problem is I wanted to use my USB2 hard drive with the hub...so I presume if I get a different USB2 hub I would still have the same problem?  I guess the answer is to use this hub for my HDD (not plugged in normally), and a get a USB1 hub for my control panel...?

Thanks again

[photorock]

        Hey guys, I think your both right on this one.

        2600 you know your USB inside and out and I learned a couple of things from you, thanks, but I have a problem with any thing that's surposed to be backward compatatble. I've seen alot of devices that were surposed to be backward compatatble and weren't. It depends on hardware, software, manufacturer and what setup you have. USB is processor intensive by way of IRQ's and in the case of CP's there is gonna be small amount of lag anyway with mouse and keyboards both vying for processor time.

        This is just my personal approach to the problem... I would disable USB2 in the Bios, exchange the USB2 card for the USB1.1 card and try that. My reasoning is that now everytning is USB1.1 compatable. The only other thing to try is to check for updated drivers for your USB2 Hub.

        I love this place, there is so much you can learn by reading the posts.

[Minwah]

       Hey guys, I think your both right on this one.

        2600 you know your USB inside and out and I learned a couple of things from you, thanks, but I have a problem with any thing that's surposed to be backward compatatble. I've seen alot of devices that were surposed to be backward compatatble and weren't. It depends on hardware, software, manufacturer and what setup you have. USB is processor intensive by way of IRQ's and in the case of CP's there is gonna be small amount of lag anyway with mouse and keyboards both vying for processor time.
[\quote]

I'm sure you're right...I hadn't even considered a problem running a USB1.1 device off of a USB2 hub to be honest.  I guess there is a mismatch there somewhere...

       This is just my personal approach to the problem... I would disable USB2 in the Bios, exchange the USB2 card for the USB1.1 card and try that. My reasoning is that now everytning is USB1.1 compatable. The only other thing to try is to check for updated drivers for your USB2 Hub.

Hmm but then I can't use my HDD at USB2 speed (which is a must for rom transfers etc.).  The USB2 hub seems to work perfectly with USB2 disabled anyway...I hadn't checked for new drivers, but I will do that now

[photorock]

       I didn't realize you had any USB2 devices (HD), that's a different story. If you want to keep those HD transfer rates up you will need USB2 support for that. That makes it a little easier, I would enable USB2 in the Bios and check for updated drivers for your hub first, If you find none then exchange the USB2 Hub for a USB1.1 Hub. Then when you first plug it in Windows will recoginize it as a USB1.1 Hub and load the proper drivers for it.

      It should work properly then. The only thing is I have never used any USB2 devices so I don't know if there are any little qwerks involved with USB2. 2600 is an expert on that. I hope this helps.

[2600]

Minwah,
Theres a couple of things you could do, but it's all about what you prefer.
Also, photrock is right about updating drivers, but I don't believe MS has released any updated drivers, plus hubs don't have "drivers" per se, they just use the standard driver that comes with the USB stack.  What you could look at is making sure you installed your chipset software depending on your Motherboard.  What kind do you have, btw?   Also, you didn't mention what OS you are using, but I doubt you reallly want to update that anyways.

Here's a couple of notes and suggested solutions:
A: You really shouldn't use a hub for your controls.  It adds a bit of delay, BUT it is convienent.
B: You could try a different hub, maybe you did get a bad one or they are using a crappy chip.  But really there pretty much the same.  If you get a different one, get a different brand and don't worry about price, money doesn't really buy you anything.
C: You are only using your USB Hard drive for updates, Right?  Well enable USB 2 when you update the roms and disable when you don't need it.  I think there's a couple of ways you could do this.
   1. The BIOS way I showed you.
   2. Then in Windows I think there is a couple of ways you could do it.  In the Windows way, you don't touch your BIOS you just leave it enabled.  I think you can create different hardware profiles and then at boot up you select which one you want.  So in one you would have it enabled, and then in the other you would disable it in Device Manager and save that profile. Or you could just enable it in Device Manager when you want to use it.  Oh, and What you are enabling/disabling in Device Manager is the EHCI controller(Enhanced Host Controller Interface).

Either way it's up to you for your situation.   Try them and see which you like the best.

[NoOne=NBA=]

Is the primary reason for the new hub that you can't access your USB ports?

If so, you might try running the controls on the old hub, and leave the new hub dedicated to connecting the HD.

[pointdablame]

If you're going to try to buy a new hub, perhaps you may consider some USB extensions?  That way you could extend the ports from the back of your computer and they would be used as 1.1 or 2.0 ports depending on what is connected no? (2600, correct me if wrong).  Also, if you used extensions, wouldn't each device be on a seperate controller? (again, let 2600 correct me, as I am not sure.)

Just an idea

[StephenH]

Try seeing if any of your USB2 ports are on separate root hubs (not the external hub) in device manager.   If so, try seeing if you can disableUSB2 on the one that your control panel is connected to, and leave it on on the firewire drive is connected to.

Also, in the device manager, try disabling error correct on the USB Root Hub that your control panel is connected to.

[Minwah]

Thanks for all the replys  Yes the main reason I wanted a hub is because it is tricky to access the USB ports on my motherboard...

What I have done is enabled USB2, and now I use the USB2 hub purely for my hard drive.

I found out an old USB1.1 hub, and I have connected that as well (fixed it next to the USB2 hub), and so I can use this purely for my control panels.  So far it seems to work fine...

Thanks again