RailPro User Group
RailPro => RailPro Specific Help & Discussion => Topic started by: William Brillinger on December 12, 2017, 07:38:50 AM
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The question was raised on another thread (https://rpug.pdc.ca/index.php/topic,538.msg4144.html#msg4144) a few days ago regarding the time it takes to transfer files with the CI-1/HC-SIM vs the HC-2.
I ran a few tests using the EMD 645 Turbo ULT File from Local Storage and I captured the process on video so I could accurately compare the times to load the files. If the video was in focus, I would post the video. It's not, so I won't. ;)
Here is what I found:
42:58 - RPA to HC-2B via USB 5:30 to 48:28
15:01 - HC-2B to LM-3S 0:36 to 15:35
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57:59 combined total time
10:32 - RPA to HC-SIM 3:12 to 13:44
36:10 - HC-SIM to LM-3S 0:41 to 36:51
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46:42 combined total time
These times only include the actual time to transfer the file.
Conclusion: The CI-1 is much slower at transferring files to the LM, but the HC-SIM is much faster at loading files from the RPA.
The key benefits of using the CI-1 remain:
- Saving battery power on the HC.
- Keeping the HC free for other tasks while loading files.
When loading program updates or smaller files, this speed discrepancy is much less noticeable.
I like to use both devices, in a tag team fashion, when there are new updates to apply or an updated sound file.
I prefer using the HC-SIM to load and program LM's and the HC-2 to test what I have done.
Cheers!
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Interesting comparison Bill. So now the question, why does the file transfer, either way, have to take so long? Is it because it takes place outside of Windows? Other, large, unrelated Windows files can be downloaded in seconds.
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So now the question, why does the file transfer, either way, have to take so long?
That's a good question, and one I have asked myself for a long time. I think our Tim might have some insight into this as he has looked under the hood a fair bit.
I don't know why it takes so long to download files from Ring Engineering's server to the RPA (a spec not covered in my test), but in my mind, this should be super fast. These are not actually large files.
As for the time it takes to transfer files to the LM, I suspect that the answer lies in the speed of the radios being used and the HC & LM's memory write speed.
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Bill, additional info may be gleaned by watching Windows Resource Monitor - Network while running your tests. You could get some idea of the communication activity going on with Ring's server.
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Here's the network load while downloading a prime mover file from Rings server:
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Well... that speaks volumes now doesn't it. Maybe Ring should consider carrier pigeon.
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...and they recently updated the server.
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Well... that speaks volumes now doesn't it. Maybe Ring should consider carrier pigeon.
Do we get to eat it afterwards? I've heard carrier pigeons are delicious.
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I think our Tim might have some insight into this as he has looked under the hood a fair bit.
Yes, some insight, and given enough time I do hope to have more but I have so few minutes to spare at this time of year to do tests and such.
So, why is this really cool system so slow to load, copy and update? Here's a few things in no order.
RPA uses UDP to communicate with Rings server. UDP has no built in error detection and correction in the protocol itself so for every bit of data sent by Ring's server RPA must basically send that same data back to Ring server so Rings server can verify what it sent was received correctly.
UDP was a terrible choice for this part in my opinion but it's likely a carry over from way back when we didn't have RPA but downloaded directly to the HC using the old internet access program (remember then?)
For RPA to HC-x / HC Sim, I haven't looked much into this but I believe UDP might used again on RPA to HC-Sim so the back and forth sending and returning data possibly applies. Not sure on RPA to HC-x. Also both the HC-x and HC Sim (emulating a HC-x) are not true USB devices, well at least the HC-2 (and HC-1) isn't. On board there is a USB to serial converter and I'm talking old school serial; I think it's RS-232 (I'll have to check again). In the grand scheme of things RS-232 is very slow with transfer rates slower than your old dial up modem.
For HC-x / CI-1 to LM, I don't thinks there's much I can do to test this to find transfer rates etc, at least for the HC-x. I might be able to work out what's going on with the CI-1.
As for the speed of Ring's server, well the old IP address pointed to an ADSL connection meaning his server was quite possibly (read likely) in his office or home, the same if you turned your home computer into a webserver, which would make the connection very slow. Where is his new server? Office or in an ISP datacentre? who truly knows but from the available information I'm leaning to his office / home. This would mean his server would have slow communications to begin with (being on a standard ADSL connection itself) and that coupled with how slow communication using UDP is that would account for the great slowing of RailPro.
These are not actually large files.
It's worse than you think! The EMD 645 Turbo ULT sound file is only 2.58 Megabytes.
- Tim
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That file should take about 1 second to download. ::)
As to the server location, Google shows the address at a strip mall, and the last package I sent was delivered to the reception desk, but I believe that location is a mail service office, and his business is within his home.
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Maybe Tim Ring is using up all his bandwidth streaming NetFlix. ;D