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View Full Version : How fed up are you with the speed of USB?


bitbank
08-26-2003, 11:24 PM
I am working on a new version of Virtual CE (www.bitbanksoftware.com) and I am including support for direct USB access (no ActiveSync). What this allows is 600K bytes per second data transfer and multiple devices connected to a single PC. The program is mainly for remote control of your PPC, but I am adding file transfer as well. I would like to know how people feel about the USB support and how far I should go with supporting things that ActiveSync does.

To clear up a few misconceptions...

1) The USB port on WinCE devices supports 12Mbs (1.1). Plugging it into a high speed USB 2.0 port will still only get you 12Mbs.

2) ActiveSync is the bottleneck reducing the data rate. With ActiveSync out of the picture, data moves at 500-600K bytes per second on all PPC2002 and PPC2003 devices. With ActiveSync, the data goes at typically 30-90K bytes per second.

3) Multiple USB connections are possible. I can connect any number of WinCE devices (PPC, HPC, SmartPhone) to a single PC and address each one individually. This can lead to some interesting possibilities for deployment of software to multiple devices (time savings). I am using this for an automated testing project.

4) Writing data to a memory card on your device is slower than writing to RAM. SD is notoriously slow on some devices compared to CF. This makes sense because the CF interface is 8 or 16 bits while the SD/MMC is 1 or 4 bits. On my HP2215 I am seeing about 300-400K bytes per second read speed from a Kingston SD card and a 100-200K bytes per second write speed (both over USB).

Larry B.

dean_shan
08-26-2003, 11:38 PM
I just use WiFi to transfer files.

petvas
08-26-2003, 11:40 PM
I am also using Wifi. Activesync in WM2003 devices is very fast and reliable. I don't feel that I need another solution and I am not really interested in such... :roll:

ctmagnus
08-27-2003, 01:04 AM
I use Wi-Fi also but I should be getting a USB 2.0 7-in-1 card reader in the next day or two.

maximus
08-27-2003, 01:25 AM
Ct, if you have time, let us know the actual file transfer speed for your USB 2.0 device for SD and CF ...

Janak Parekh
08-27-2003, 02:20 AM
I just use WiFi to transfer files.
This is what's so mystifying to me. If ActiveSync works so well over Wi-Fi (and it certainly does work much faster than USB), it would be cool to see the next-gen ActiveSync just use network-based connections exclusively, and have the USB connection emulate a LAN connection. All of the legacy USB code which originated from the serial code from the ancient Services for CE platform should be nuked, IMHO.

--janak

bitbank
08-27-2003, 03:13 AM
Wifi with ActiveSync is not very fast. On my HP2215 and a Symbol CF wifi card I am seeing about 250K bytes per second copying a file with ActiveSync over Wifi. With direct USB (no ActiveSync) I am seeing 600K bytes per second. ActiveSync slows down whatever connection you are using.

L.B.

buckyg
08-27-2003, 04:45 AM
FWIW, bitbank, what you're talking about with USB sounds interesting to me. If it is AS that is slowing things down (sounds like it), I think there's some market for file transfers and possibly for whatever you're considering to get around AS. Will have to check out Virtual CE, current version and keep an eye out for future versions

While I do use the Wifi on my PPC, I usually don't sync with it. I also know several others who don't either. I have a 7-in-1 reader but it's not always handy to drag it out or take it with all my other stuff.

Regards,
buckyg

ctmagnus
08-27-2003, 04:49 AM
Ct, if you have time, let us know the actual file transfer speed for your USB 2.0 device for SD and CF ...

Sorry to disappoint, but I bought the USB2.0 stuff for future-proofness, ie when I finally get a laptop. The machine it's going on now is (I believe) actually USB1.0 and not even USB1.1. I'm hardcore! :mrgreen:

doogald
08-27-2003, 02:09 PM
As someone who started with ActiveSync on a CE 2.01 device running on a serial port, I find USB via ActiveSync to be quite fast, actually.

I also have WiFi at home, though, and when I do sync at home, that's also really fast.

However, the ability to access data quickly via USB without having to use ActiveSync? That does sound a little bit intriguing.

wardseward
08-27-2003, 03:16 PM
Why didn't HP have the new line of ipaqs come with USB2 compatable cradles?

bitbank
08-27-2003, 03:26 PM
wardseward,
HP's cradles are compatible with USB 2.0, but operate at 12Mbs. The Pocket PC can barely keep up with a 12Mbs link, there is no point in adding a 480Mbs one.

L.B.

ctmagnus
08-27-2003, 07:32 PM
Something that may be worth pointing out:

I've found that if a Pocket PC is directly connected to one of my USB ports and turned on, all other devices connected via USB are painfully more slow than usual.

gorgoroth
08-27-2003, 09:55 PM
Being able to transfer data with a direct usb program is interesting, although i have a card reader for this.

Being able to remote control the PPC is nice also, and I would love that not being dependant on activesync.

But having a bridge or proxy support that allow internet passtrough without activesync, in a simple exe that can run from a floppy, that would be a dream for me...

I don't know if you plan to add this kind of function to your program, but if you do, I'll be your first customer.

famousdavis
08-27-2003, 10:30 PM
I am not wireless anything. ActiveSync is verrrry slow in moving files like my Pocket Backup file and when moving WMA or MP3 files.

Therefore, I'd certainly be interested in a software solution that could move files to the storage card on my PPC (an HP1910) that would be quicker than going through ActiveSync.

maximus
08-28-2003, 01:41 AM
Something that may be worth pointing out:

I've found that if a Pocket PC is directly connected to one of my USB ports and turned on, all other devices connected via USB are painfully more slow than usual.

That is strange. I always have a card reader in my #1 USB, and #2 USB is for the axim. When I simultaneously transferred data to both devices at the same time, I dont see any significant drop in data transfer. From what I read, USBs are independent device, which means USB #1 and #2 do not share bandwidth.

ctmagnus
08-28-2003, 05:31 AM
Something that may be worth pointing out:

I've found that if a Pocket PC is directly connected to one of my USB ports and turned on, all other devices connected via USB are painfully more slow than usual.

That is strange. I always have a card reader in my #1 USB, and #2 USB is for the axim. When I simultaneously transferred data to both devices at the same time, I dont see any significant drop in data transfer. From what I read, USBs are independent device, which means USB #1 and #2 do not share bandwidth.

Also worth noting in my situation: the desktop CPU is 200MHz. That may affect the transfer speed. :mrgreen:

maximus
08-28-2003, 06:41 AM
Also worth noting in my situation: the desktop CPU is 200MHz. That may affect the transfer speed. :mrgreen:

:bangin:

It is interesting to see that your PPC is faster than your desktop :p

ctmagnus
08-28-2003, 05:05 PM
:bangin:

It is interesting to see that your PPC is faster than your desktop :p

And I'm proud of it! :mrgreen:

I don't see the real need to upgrade. Until my dream notebook comes along and I can afford it, that is. After all, I dont game and the only real problem I have with thsi machine is with WMP7. But Winamp plays anything WMP chokes on without a hitch. I have no hardware hangups. The only thing really missing from this machine is more accessible USB ports.

maximus
08-29-2003, 02:27 AM
What version of windows running on your desktop ? I have an IBM PS/2 model 30 (8086 processor at 12mhz and 20MB harddrive) back in singapore, and it is still up and running. :rock on dude!:

Steven Cedrone
08-29-2003, 04:15 AM
Lets get back on topic...

Please???

Steven Cedrone
Community Moderator

buckyg
10-28-2003, 05:12 AM
Larry B.,

Any news on this project? (New version of Virtual CE w/ file transfer)

Thanks and regards,
buckyg

JustinGTP
10-29-2003, 02:42 AM
I use Wi-Fi also but I should be getting a USB 2.0 7-in-1 card reader in the next day or two.

Thats what I plan, but not just in a day or two.

-Justin.