Speedtouch 330 USB Bandwidth (Windows XP)

Hi,

I have been using a Silver Speedtouch 330 for a while now on 1Mb, and now on 8Mb. Looking at all the documentation and stuff on the internet regarding drivers and such I have a little question.

I have tried both the standard drivers and the 8Mb drivers. To be honest performance is good (when the ISP is working ok), its better with the 8Mb drivers which forces the modem into Isochronous mode (the best I have seen is http://www.speedtest.net/result/66469152.png ).

If I use Isochronous mode the modem reserves only 75% of the USB Bandwidth on that controller (Which sets the USB Bandwidth of the modem at 7680 and hence the line syncs at 7680, it will sync at the full 8128 in Bulk mode, yet the performance is not as good).

My question then is, why does the modem only reserves around 75% (7680) and not the full 8128 which still would not be 100% bandwidth of the controller.(Windows device manager reports 75% reserved for the modem)

I tried asking Thompson themselves but their support is abysmal, they wont answer the question and just direct me to speak to my ISP (who have no clue) or microsoft (who are not interested).

Is there a way of configuring the USB Bandwidth given to a device in Windows XP?

Cheers,

Mike

Above about 4M sync speed the 330 will suffer regardless of drivers - simply because it's a USB 1.1 device (top whack 12Mbps on the bus, Windows reserves 10% of that and once you get above about 50% capacity you will start to get collisions on the USB bus, triggering retransmits on the ATM side - which will drop the perceived speed). As you see with the isochronous driver sync is lower but throughput higher....

For anyone out there doubting the suitability of a USB modem for the ADSLMax service, a read of this from BT may be a little more convincing: BT IPstream Office, BT IPstream Home, BT IPstream Max & BT IPstream Max Premium Products, Service Description and Interface Specification - section 5.1 on Page 14 of that PDF (which is BT's description to ISPs of the ADSLMax service)

The answers are here!

I have read the FAQ before, it doesnt tell you how to (if you can) configure the USB bandwidth reservations at all, it just says what the difference is between Bulk and ISO modes. I knew that anyway but, thanks.

The reply I got from Thompson support, said its a windows configuration issue and to talk to MS.

Edited by deleted (Mon 18-Dec-06 15:30:54)

But you'll get no further with a USB 1.1 device - you need either a USB 2.0 highspeed (480Mbps) device or something connected via ethernet (wired or wireless).

I also have SpeedTouch 330 USB ASDL Modem connected to USB 2.0 port of an IBM Thnkpad. I use Broadband Max with Fast.co.uk. It is an 8 Mbps service. They promise a real life 3-6 Mbps. I live only 1 km from the exchange and get close to 6 Mbps.

Below is a test result from http://speedtester.bt.com
IP profile for your line is - 6500 kbps
DSL connection rate: 448 kbps (UP-STREAM) 7616 kbps (DOWN-STREAM)
Actual IP throughput achieved during the test was - 5994 kbps

I was surprised to know that Stormy is getting 8394 kbps.
What dio I need to get this?

The only way to improve your speeds would be to increase the sync speed, and then let the IP profile increase, although what you're getting looks very good anyway.

Have you tried connecting via the Master Socket (removing the face plate, and using the socket underneath) to see if that improves your Downstream DSL connection rate at all?

I doubt you'll be able to do much to improve what you're currently getting though.

Anon...

Many thanks for your comments and putting my mind to rest about the connection speed I am getting.

I will try what you suggested. But not to the extent Hi-Fi enthusiasts go to get best connections. Silver plated OFC cables and inter-connects, fancy cable geomtries, elaborate screening, gold plated contacts and so on.