One more reason why USB 2.0 SUCKS!!!!

[Jammrock]

To the MURCers who work at Intel, I apologize. I'm sure you are not the ones to blame for this, so I hold no grudge against you ... just the morons who designed USB 2.0.


It is official, Intel has made my sh*t list. I have been researching and researching and trying to figure out why, oh why!, my USB 2.0 hard drive were running like sh*t on my computer. It acted as if the transfer rates were running in USB 1.1 mode. As it turns out, they were ... and this is the reason why.

Apparently the geniuses at Intel who "overhauled" USB 2.0 to make it "480 Mbps" decided to share the USB 1.1 and USB 2.0 controller. This means that if you use a USB 1.1 device, say a USB mouse, ANYWHERE on the same system as a USB 2.0 device, ALL USB devices are switched to USB 1.1 mode.

You would think, all logically and like, that if you kept your USB 2.0 devices on your USB 2.0 ports, and your USB 1.1 devices on your USB 1.1 ports this would not happen. But !!!NO!!!, Intel f***ed up and even if you keep USB devices on the respective ports, if there is ANY USB 1.1 device plugged in ANYWHERE in the system, even all your USB 2.0 ports will drop to "full-speed" mode, which is max throughput of 12 Mbps.

Before you people get up in arms about "it's not Intel's fault, it's a poor mobo design" let me clarify the system I am working with. It is a Dell Optiplex GX260, which uses an Intel designed and made mobo. All Dell does is tweak the BIOS to their liking. So yes, this is an Intel problem.

Stupid, stupid, stupid, stupid, stupid, stupid, stupid, stupid, stupid, stupid, stupid, stupid, stupid, stupid ...

Jammrock

[William]

I'll have to get out the standard to check; but I'm pretty sure that this is non compliant behaviour.

BTW the easiest work around is probably to either fit a PCI USB controller; or to plug in an external USB 2.0 hub, and plug the mouse into that.

[Tjalfe]

Way to go intel
I run a USB 1 mouse and a USB 2.0 memory device on the same computer (Nvidia based A7N8X-X) and it works fine, so USB 2 itself is not to blame, just intels implementation it seems.

[dZeus]

no problems either running low-speed and high-speed USB devices off my Intel branded mobo at the same time.

[High_Jumbllama]

It's gotta be the implementation.

It's usually 1 to 4 controllers usually all on the same chip on the motherboard, running to the same number of sets of ports. 1 usb 1.1 device on one set will drop the set to 1.1 but not any ports on the other set(s)/controller(s). Initial implementations had motherbaords with ports specifically supporting 1.1 and the others were 2.0.

[knirfie]

no problems here using USB1.1 and 2.0 hardware next to each other:

USB2.0 Hardware

40gb hdd
128mb flash drive

USB1.1 Hardware

Mouse
Webcam

Both the harddrive and the flash drive work at normal speeds (flash reaches 5-6mb/s and 40gb hdd 30mb/s). Maybe a problem is causes if i connect an USB1.1 and an USB2.0 device to the same internal hub, but i've never tried that.

[SpiralDragon]

i know USB is prety mutch standard and all but i wouldnt go and use an HDD on USB x .... firewire is the way to go in this one.. atleast IMHO..... although this does pose a problem if using flash drives that are USB2.... heh... try transfering 1gb of data at the 1.1 speeds.... not an enviable position.... intel has to get its act together ... its been ****ing up too mutch in the last few years.... having said that, i still prefer intel over AMD...

[High_Jumbllama]

I had bought an enclosure for USB just because it could connect to any computer even if at a slower speed. If I had the money at the time, I would have gotten one that does IEEE 1394/Firewire.

[agallag]

I happen to be using a Dell Optiplex GX260 right now (1.8GHz P4, 1GB ram). I have the following USB devices plugged in:

Logitech Wheelmouse Optical (1.1)
Compaq Ipaq 3650 (1.1)
Sandisk 6in1 flash reader (2.0)
Sandisk Cruzer Mini 256MB flash drive (2.0)
Yamaha CRW-F1 44x burner (2.0)

Everything works fine, even when using all 5 devices simultaneously, and the burner is definitely running at usb2.0 speed, since I can burn a full 700MB CD in under 4 minutes. I even tried copying data from a CF card to the cruzer, while burning a CD and syncing my ipaq, and there wasn't a single hiccup. The buffer on the burner never went below 99%.

Either your OS is screwed up (I'm using XP SP1 by the way), or you got some dud hardware from Dell. It's definitely not a problem with all GX260s.

[spadnos]

You do realize that you NEED a USB2.0 compliant cable??

The way the USB controller detects whether to use USB1.1 or USB2.0 requires a cable with a full shield, and it needs to be connected correctly at both ends.

Try a Super Snazzy cable, and see if the problem persists.

FWIW, I use a USB1.0 or 1.1 mouse and a SanDisk Cruzer Mini on the same controller, and the Cruzer really cruzes.

- Steve

[rylan]

Oh you can get a usb2.0 device to run on an old usb1 cable.. it'll probably even work until the error dection kicks in and slows it down. I have a couple good shielded usb 1.1 cables that work fine with 2.0 devices because somebody knew how to make a good cable back then

[agallag]

I read that the specs for a USB 1.1 cable are identical to the specs for a USB 2.0 cable. You only run into problems when using cheap USB 1.1 cables that aren't really up to spec. Can't remember where I read that though...

[leech]

I've been running an Asus P4PE (using the intel i845PE chipset) and it works fine. I have a USB keyboard (which has two usb ports on it... ok it's not really a USB keyboard, since it has the PS/2 connection which has to be connected, but it has a two port hub on it, which I plug in my mouse and steering wheel.) Along with a USB 2.0 enclosure with a 200gb harddrive in it. No problems with the speed here. I just hate it that Windows for some odd reason always insists on running some sort of scan at the boot up that looks on that harddrive (I had a theory that it was the autoplay, which Windows has the tendancy to run whenever I plug the drive in while Windows is already running) but I turned that off through TweakUI and still have the issue... Though it could be that TweakUI is just not loading up the settings to disable Autoplay until AFTER Windows tries to detect the drive.... It does this 'detecting' right before the logon screen comes up....

Leech

[spadnos]

Originally posted by agallag
I read that the specs for a USB 1.1 cable are identical to the specs for a USB 2.0 cable. You only run into problems when using cheap USB 1.1 cables that aren't really up to spec. Can't remember where I read that though...

A good quality USB 1 cable works with USB 2 in high speed mode. Unfortunately, a lot of USB cables aren't even fully USB 1.1 compliant and won't work at USB 2 speeds.

I took a class on implementing USB 2.0 at Embedded Systems Conference a couple of years ago (which is why I can't remember the specifics ). Basically, the controller grounds each of the signal pins, and checks that the other pin still functions in some way, which won't happen unless the shields are properly connected. Vague enough for you?

I'll try to find something about it if anyone's interested.

- Steve

[rylan]

The amazing thing is USB uses a differential signal standard, so its even harder to screw up the signal integrity unless the cable is really a piece of crap.
Oh I think the power conductor on usb2 cables can carry more current.