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View Full Version : Podcatching and DLs to PPC pretty unspectacular at the moment...


floepie
08-17-2006, 08:19 PM
Why is it that DLing large files directly to the SD card using a PPC's wi-fi access is remarkably less than spectacular? I've tried Egress to DL podcasts and update feeds over wi-fi, but the speed with which this happens is quite a bit slower than I would expect, even with an 802.11b connection.

I have an imate JAMIN with a 150x SD card which I thought would make a difference, but the difference is hardly noticeable when compared to a slower card (50x). Furthermore, if the update takes place overnight, the risk of leaving wifi turned on well into the next day sort of ruins the whole experience, as you can barely make it a whole day with the wifi turned left on.
I really was hoping that I wouldn't have to rely on the PC for podcatching in favor of DLing directly to the PPC, but I have found that the easy access to the SD card on the JAMIN and an available SD slot on my laptop for syncing not as cumbersome as I anticipated and a whole lot faster if the need to update on short notice arises.

This process of removing the SD card much like removing a floppy works much faster than via ActiveSync wired or wireless using bluetooth and Mobsync, which many have found invaluable for this purpose.

I have settled on iTunes as a means of receiving podcasts on the PC only because of the nice way in which podcasts can be searched by relevence and popularity and the myriad of reviews for many of the feeds. I then use a backup/sync app (Syncback) to sync the iTunes podcast folder on the PC to the Podcasts directory on the SD card and have used this as a "favorite" in Mortplayer. When iTunes deletes an episode, the corresponding episode on the card will be deleted as well.

Using this method of syncing, the file structure is maintained, unlike when PC media managers are used that employ libraries which arrange the diretory structure on the PPC according to tags such as "artist", which quite often is unrelated to the feed's title and results in the user trying to associate these "artists" with the proper feed.

So, until the devices are shipped with bigger batteries and can DL files with greater speeds, using the SD card as a "floppy" seems to work best for me, as of now at least.

Cybrid
08-18-2006, 05:23 AM
Why is it that DLing large files directly to the SD card using a PPC's wi-fi access is remarkably less than spectacular? I've tried Egress to DL podcasts and update feeds over wi-fi, but the speed with which this happens is quite a bit slower than I would expect, even with an 802.11b connection. Simple answer? Your Pocket PC is not as fast as your laptop.
Detailed answer? Your laptop employs x86 based CPU architecture with loads of high BUS speeds and Bandwidth. Your Pocket PC has an StrongArm based architecture with a lower BUS speed and Bandwidth.
Imagine a door...500 People per second and 15 people wide= 7500 People per second.
Imagine another door... 400 People per second and 5 people wide...=2000 People per second.
What line would you like to be standing in?

http://www.webopedia.com/DidYouKnow/Hardware_Software/2005/computer_bus.asp

Smaller devices are always going to be slower. You could compare a PPC to a 25 year old PC and be close to speeds if that'll make you feel better? :lol:

floepie
08-18-2006, 05:32 AM
Ok thanks for the explanation, but we're talking *much* slower for PPCs. Strong 802.11b wifi connections result in, what, 5-6 Mb/sec, right? Those speeds are still slower than the actual benchmarked read speed of my storage card. I know nothing about chip architecture and bus speeds, but if the PPC can accept a stream from a card at those speeds, why aren't PC wi-fi speeds at least somewhat approachable on the PPC?

Well, I think that the greater bottleneck most probably is the write speed to the card, which is typically 10x slower than the read speed, so I suppose that would explain the difference in DLing podcasts and other large files directly to the PPC....

Cybrid
08-18-2006, 05:47 AM
Ok thanks for the explanation, but we're talking *much* slower for PPCs. Strong 802.11b wifi connections result in, what, 5-6 Mb/sec, right? Those speeds are still slower than the actual benchmarked read speed of my storage card. I know nothing about chip architecture and bus speeds, but if the PPC can accept a stream from a card at those speeds, why aren't PC wi-fi speeds at least somewhat approachable on the PPC?

Well, I think that the greater bottleneck most probably is the write speed to the card, which is typically 10x slower than the read speed, so I suppose that would explain the difference in DLing podcasts and other large files directly to the PPC.... But I haven't seen a PPC get 5-6Mb/sec... do a test... I'd say 700Kbps tops... With as you say a significantly slower write speed to SD cards...

floepie
08-18-2006, 06:02 AM
No, I meant the storage card gets 5-6 Mbps read speed. I was just making a very crude comparison between the bus that shuttles data from the card and the bus that shuttles data from the wireless adapter. But, even if those wireless speeds were attainable the PPC can't do anything with data that fast anyway I suppose.

This kind of dampens my enthusism for higher data rates offered by HSDPA and the like...

GSmith
08-18-2006, 03:04 PM
I regularly get 125 kbytes per second and occasionally up to 200 kbytes per second enclosure downloads using FeederReader on my Windows Mobile Smartphone over WiFi. This is equivalent to 1-1.6 megabits per second. I find it to be fast enough for daily use. This is using a "standard" SanDisk miniSD card (not the Ultra II). It often depends on the speed of the host serving the file. Some servers are faster than others, and I've seen anywhere from under 10kbytes per second to 200kbytes per second depending on the server.

I see similar speeds using FeederReader on a Pocket PC over WiFi.

With FeederReader, you can adjust the number of feed connections and the number of enclosure connections separately to optimize the use of your card and your connection. Setting up to receive multiple feeds (particularly from different hosts) can improve overall download and write times.

Greg Smith
Author, FeederReader - The Windows Mobile RSS Aggregator - news, blogs, audio, video, podcasts direct to your device
www.FeederReader.com - Download on the Road

floepie
08-18-2006, 03:45 PM
After having tested the speed of my new PQI 150x 2GB SD card, I'm finding an average of 850KB/s read and a measly 70-75KB/s write speeds.

Does this seem like a faulty card? My 50x card was writing roughly 150KB/s. So, the max speed I could DL something to the SD card is 70KB/s.

For a 140MB video, that would be ~31 min. 8O

Now, on the face of it, it doesn't sound too terrible for this 1 video, but if multiple vids and audiocasts are DL per update, this can really add up.

I think I'll try to get some real world DL's going from a good server to see if the DL speed matches the write speed of this card.

Do you know of a benchmarking app that would give this info?

GSmith
08-18-2006, 04:53 PM
I think it's free for personal use: http://www.spbsoftwarehouse.com/products/benchmark/?en

I haven't tried it though. I've worked on optimizing enclosure downloads quite a bit within FeederReader so using FeederReader directly has given me all the benchmark data I need ;-)

Greg Smith
Author, FeederReader - The Windows Mobile RSS Aggregator - news, blogs, audio, video, podcasts direct to your device
www.FeederReader.com - Download on the Road