What is the data transfer speed of the sansa fuze charge/data transfer cable?

What is the data transfer speed(mb/s) of the sansa fuze charge/data transfer cable?:smiley:

(cable provided buy sandisk when bought)

The Same Speed as your usb port.

time it

just 'cause a cable carries 480mbps doesnt mean the device uses the full bandwidth

slower is cheaper in designing <$100 electronics

(remember to use bits not bytes, as bytes are full characters)

ALWAYS ALWAYS ALWAYS divide bps by 10, NOT EIGHT

There is no such thing as a data-only protocol, there are control and error bits in just about every

transmission line protocol

reminds me of the days people thought baud and bits were the same during the days of modems

engineers have since found ways to push more than one bit per symbol down a pipe

(use more than one freq channel etc)

i digress

the electronics chipsets on EACH SIDE of your transmission line are factored into these speed calcs too

if all things were created equal , there would not be any differences in products, but there are

one lame example:

http://www.tomshardware.com/charts/compact-flash-memory-card-charts/File-Server-Benchmark-Pattern,854.html

not all mp3s are created equal

but you DID ask what is the transfer speed of the cable, not the electronics on each end of the cable

so the stock answer is 480mbps USB v2.0

Message Edited by bytehd2000 on 02-24-2009 03:37 PM

480Mbps is the theoretical maximum speed for USB2. Typically, it can’t get close to that just because of the architecture. But it doesn’t matter when you’re using flash with read speeds about 1/10th of USB2’s actual max, and write speeds much slower than that.

Message Edited by bdb on 02-24-2009 08:34 AM

Here’s what I measured using CrystalDiskMark… 

Sansa Fuze 8GB

Sequential Read :    5.648 MB/s
Sequential Write :    3.958 MB/s
Random Read 512KB :    5.644 MB/s
Random Write 512KB :    2.017 MB/s
Random Read 4KB :    2.531 MB/s
Random Write 4KB :    0.029 MB/s

HDTach 3.7 gives me:

on 8GB Fuse

Random Access: 3.1ms

Avg Read: 4.2MBPS or 42mbps (out of 480mbps max)

Burst Read: 4.4MBPS or 44mbps

8GB Verbatim Store_N_GO flash drive:

Random Access: 10.4ms

Avg Read: 29.9MBPS or 299mbps (out of 480mbps max)

Burst Read: 31.1MBPS or 311mbps

Fuse is slow compared to a bare drive.

for fun:

Seagate  3120022A - 120GB PATA internal

Random Access: 15,ms

Avg Read: 45.7 MBPS or 457mbps (PATA bus max 133 MBPS or 1330mbps)

Burst Read: 91.0MBPSor 910mbps

this is why hard drives still rule

I get about 350-375KB/s.

@bytehd2000 wrote:

Avg Read: 4.2MBPS or 42mbps (out of 480mbps max)

 

For someone named bytehd, I would have thought you knew that there are only 8 bits in a byte, not 10. 4.2MBps = 33Mbps. :wink:

That sounds about right, though. I’ve also noticed my (Sandisk) flash card transfers faster than the internal flash.

Message Edited by bdb on 02-24-2009 08:17 PM

re-read my post

im not talking about character storage

character transfer

watch this, youll love it:

8 data bits, no parity, 1 stop bit

imagine that

im done here

Sorry, a byte is still 8 bits in data transfer, too. 8N1 is low-speed asynch serial, completely irrelevant to USB which uses data packets with up to 1024 bytes of data in each packet.

@bytehd2000 wrote:

re-read my post

 

im not talking about character storage

 

character transfer

 

watch this, youll love it:

 

8 data bits, no parity, 1 stop bit

 

imagine that

 

im done here

I understand what you mean.

However I’m not sure the parity and stop bit still exists in USB on a 10 bits basis as your,e saying (maybe you’re already an expert on USB specifications and you know, I’m jsut saying…)

But if you look at the USB specificaiton (USB 2.0), there is a lot of CRC, PID, SYNC bytes (not bits) and it gives different usefull data payload depending on several factors and protocol consideration. So clearly, the old rule of divinding by 10 is not true anymore, at least to give usefull information.

So even if there is still stop/parity, you need to consider all the overhead if you think you are really talking about the usefull data payload used by the device.

It is basically hard to calculate for USB, you need to test it to see really as it depends on many factor.

One thing I know for sure, is that you don’t absolutly need exactly one a stop bit and one parity for every byte of data you want to trasnfer. I’ve done it myself for smal circuitry, and you can manage some kind of sync bytes or you can do it for not every byte at least (using serial communcation) (not sure if that is what USB specificaiton is also talking about and I’m not a USB technical expert myself).

Finally I don’t think I will apply your recommentation (or “rule”) of: “ALWAYS ALWAYS ALWAYS divide bps by 10, NOT EIGHT”, I actually prefer to divide by 8 to give me an actual idea of number of bytes flowing in the stream (even if it is garbage, sync bytes, stop bits, crc or actual data, it doesn’t matter).

Message Edited by freydrich on 02-25-2009 12:03 AM