Why is C500 Data Transfer Rate still slow despite mini USB?

[Guest ghm101]

The C500 seems to have an abysmally slow transfer rate over active sync on the cable, as a experiment I also tried Bluetooth and thats not worth commenting on.

There doesn’t seem to be any benefit, data throughput wise, in the switch to a mini USB cable with the SPV c500. Performance seems similar to what was reported in the topic http://smartphone.modaco.com/viewtopic.php?t=2094 - "Active sync USB file transfer speeds very slow"

For shifting large volumes of songs you could use the Windows Media Player 10 “Sync” function – set it off when you go to bed and let it run so it is ready for the next day – but who wants to have to think that far ahead?

Ok so you take your Mini SD card out and shove it in a reader.

– I’ve got a USB2 reader thingy and it is very fast by comparison.

– Seems like it takes longer to take everything to bits and put it all back together again than it does to shift a couple hundred MBs about.

But I worry about things working loose – 6 months down the road end up with a phone that falls to bits or just stop working because the battery doesn’t fit snugly any more :cry: …and what happens if me mum wants to ring me when me phone is in pieces :?:

As a test I tried the following methods to transfer 30.1MB of songs:

USB Card Reader

Time taken 0:00:19

MB/sec 1.584

USB cable Media Player 10 Sync via active Sync

Time Taken 0:02:25

MB/sec 0.208

USB cable Active Sync

Time Taken 0:02:05

MB/Sec 0.241

Blue Tooth via activesync

Time Taken 0:15:20

MB/Sec 0.0327

Mainly because I like every thing to work I was a bit disappointed not to see the Device recognised in Windows Media Player 10 when connected via Bluetooth.

Considering you can buy a fairly small USB2 card reader for 15 ish quid it would have been nice if they could have got some of that tech into the phone.

My main gripe about this is how they failed to fulfil the potential of existing tech in this area.

If anyone knows ways of speeding the process up let me know.

I still love the phone though :) .

[Guest zippy172]

Looks to me as though the USB interface on the C500 is V1.1 @ 12Mbps ^_^

[Guest midnight]

seeing as i've come from an E100 with serial interface i actually find the C500 transfer extremely fast, 30mb in 2 mins aint that bad, how often would you be transferring 30mb? and how ofen would you need to do it really urgently?

[Guest zippy172]

Well... I'm not the original author of this thread, just having a grumble on the side I guess.. If the C500 had been shipped with USB2, everyone would be laughing... I've just taken delivery of a lovely Trancend 512Mb Mini-SD card, the last thing I want to do is to have to open the phone up every time I want to fill the card with mp3's - It simply isn't convenient enough to either pull the phone to bits, or wait forever for files to copy over the USB lead...

As someone said in another thread, it was a major wrong doing for the spec of the rest of the phone... ^_^

[Guest zippy172]

....as was the p!$$ poor implementation of BlueTooth :twisted:

[Guest ghm101]

It would be interesting to know exactly where the bottleneck is.

Are there other applications, other than active sync, that can transfer data to the phone?

if so - do they do so at the same sort of rate as active sync connected via USB?

If other applications generate the same data rates then I think it it is a reasonable assumption that the underlying hardware determines the data thru-put.

If this is not the case maybe there is some limitation in Activesync that determines the capability.

Anyone got a way to test this?

[Guest zippy172]

If my assumption is correct, that being the interface is USB V1.1, then the bottleneck is the maximum data transfer speed of 12Mbps... ActiveSync isn't going to impede the flow greatly....

[Guest ghm101]

I wouldn't be surprised if it was just USB 1.1, It would just be nice to know for sure.

I always find these things a bit difficult as advertised thru put is always a theoretical maximum

(- achieved in the land of oz only when clicking a pair of red shoes together on a any day of the week as long as it has a "K" in it.)

Following my test I'm tempted to say the thing is serial once it gets off the mini usb lead :?

[Guest pisquee]

USB is a serial communication. I guess what you are meaning is that is RS232 once it gets inside the phone?

[Guest ghm101]

Yes that is what I mean

- as usual I got the techie side wrong.

(The only piece of Jargon that I authoritively know about is what PCMCIA stands for = People Can’t Memorise Computer Industry Acronyms)

Fully prepared to be wrong on it but 30 MB in 2+minutes (see original post) is not anything like the 12MBps of USB 1.1.

[Guest pisquee]

12Mega bits per second NOT 12Mega Bytes per second

[Guest zippy172]

Yes, V1.1 is 12Megabitspersecond, hence the small 'b'. V2.0 at 480Mbps is slightly more useful...

As for the USB serial interface to the cpu inside, it most definately does NOT translate back to RS232 :!: Perhaps SPI or I2C yes, definately not RS232.

[Guest ghm101]

hmmmmm...

30.1 MegaBytes transferred in 125 seconds...

=

240.8 Megabits @ 1.9 Mb per sec

not quite 12 Mb per sec specified by USB 1.1

Why do these things always under-perform :?:

also =

246.57 KiloBytes per sec

1972.63 KiloBits per second

.02930 GigaBytes per second.

From the above you can either conclude I have a fundamental

understanding of the units of measure and their conversions

or

I found a website that converts these things for me ^_^.

(so in the tradition of modern leadership I can blame "the system" rather than "the individual" if I got it wrong.)

[Guest midnight]

have you taken into consideration all the other stuff that goes on while transferring a file? not only does it need to transfer it needs to write somewhere, and that will slow the process down slightly, there are various factors why actual transfer speeds are never met. Ok, it doesnt explain why its actually 'that' slow, but it would account for some loss in speed.

Even closing down apps on the phone speeds up the data transfer ^_^

But either way, i'm quite happy with the transfer speed to be honest, never really bothered me on the original SPV, and certainly doesnt bother me now its much quicker.

[Guest zippy172]

Just disappointing the interface isn't USB2 really....

[Guest Taoski]

When i read about the C500 being Mini-USB - i expected the slow transfer rates i get on my SPV1 to be resolved.

Glad to hear its quicker... shame its not "super quick"!

[Guest RikF]

There is any easy way to tell if a device is USB 1 or USB 2 (the C500 is 1 btw). Plug it into a PC running XP and with a USB 1 interface. If it is a USB 2 device you'll get a 'friendly' little message from Uncle Bill telling you that you have a high speed device plugged into a low speed interface.

RikF