Vodafone 3g HSDPA modem speed limited by PC port speed ?

I've just got hold of a Vodafone 3g USB modem (E220) and plugged it into a USB port (COM4) on my Dell Dimension PC.

The speed is very erratic when measured using http://www.irishisptest.com/
Anywhere from 30Kbps to 1Mbps, but mostly around 200Kbps.

Looking at the USB port settings, I see the speed is set to 460800 (presumeably bps).

Does this mean that regardless of the modem speed I can not get better than 460800 bps ? Is there any way to change this upper limit ?

Haven't seen any mention of this limit in the modems documentation.

When you use a speed-test like that or all of them, they give an estimate of your ISP, not your USB or Modem speed.
And I didn't know that you could limit a usb speed?

That USB speed is 480 Mbit/s.... (that a bit M , so Megabyes)... your speeds sound about correct... in the region of what I get...

jhegarty said:

That USB speed is 480 Mbit/s.... (that a bit M , so Megabyes)... your speeds sound about correct... in the region of what I get...

Click to expand...

Are you sure about that? Do a Google for "HSDPA", "USB" and "460800" and you will see posts/info elsewhere on a similar topic.

BTW - 480Mbps = 503316480 or 480000000 bps depending on what definition of K is used (1024 or 1000) so I don't see any correlation to the number 460800 here.

Seems that the bit rate of the USB virtual COM port/UART of 460800 is standard and/or not really indicative of the actual raw throughput possible.

Measurements of my download speed over a day has shown i'm getting between 600 - 982kbps. Not bad, i suppose, for indoors and my rural location. After 6pm it drops to around 200k for some reason.

Looks like Sn@kebite and Clubman are correct, the 480600 limit is the ports thru'put (USB Modem <--> USB Port) and nothing to do with the ISP speed.

You can limit the USB speed in 'Control Panel' -> 'Phones and Modems' option.

Probably more sharing the node?

We use some of those 3G modems in our office and have had some signal problems with them, as in it can be hard to get a good signal in some locations.

redstar said:

Measurements of my download speed over a day has shown i'm getting between 600 - 982kbps. Not bad, i suppose, for indoors and my rural location. After 6pm it drops to around 200k for some reason.

Click to expand...

That is most probably due to "contention". i.e. the number of users of this wireless service peak at around 6pm or so. That would be right due to ppl arriving home from work (after using the internet on a workplace ADSL connection) and want to send emails, brouse etc.. So your ISP shares your connection with these 3G customers.

So: If you have a 1Mbit connection and your contention is 48:1, that means that your connecton speed can range from max. 1:1 (1024kb/s or 1Mbit/s) to min. 48:1 (21kb/s or c.0.021Mbit/s) but cannot be any lower than that, If you are interested in these technicals lol.