05-21-2004, 12:00 AM
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Magi
Join Date: Feb 2004
Posts: 2,186
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Tom's Networking: WiFi PDAs' Dirty Little Secret
"I first stumbled upon low WiFi throughput in PDAs last fall, when testing SanDisk's SD WiFi card in an HP H2210 iPAQ running Pocket PC 2003. The tests for that review yielded best case average throughput of only about 350kbps. Both SanDisk and SyChip (who makes the card for SanDisk) said that the main factors in the low speed were software and hardware issues in the H2210's SDIO interface. What I found after a little digging seems to confirm the SanDisk / SyChip story, though there is some conflicting info. The SD interface on Intel's PXA255 XScale processor used in the H2210 (and in many current PocketPCs) is actually an MMC interface capable of supporting only the 1 bit transfer mode at a maximium 20MHz clock rate(1).
Even though it's not an SD interface per se...the MMC 1 bit mode is theoretically capable of supporting a 2.5MB/s (20Mbps) transfer rate. This should be plenty fast to support 802.11b's full 11Mbps raw data rate, as long as software overhead isn't a significant factor. But my experience with some of the PXA255-based PDAs that I tested yielded WLAN transfer rates far below what you'd expect for such relatively fast raw bus speeds. So it would appear that there are some software or other issues at play that limit wireless throughput."
As always, Tom's has done an excellent job of dissection and testing. The tests in this article are done with an HP 2210 with a SanDisk SD WiFi card, a Dell Axim X5 Advanced with a SanDisk WiFi card, an Asus A716, and a Palm Tungsten C. All of these devices use the 400MHz Intel PXA255 processor (except the Axim, which uses the PXA263 chip), but they all use different methods of getting the signal to the CPU. The device with the highest throughput had a speed almost three times faster than the next closest device. To find out which device "won", you'll need to read the article.
Hint: :mecry:
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05-21-2004, 12:13 AM
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Sage
Join Date: Jul 2004
Posts: 658
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So this article only refers to using the SD Wireless card right? I'd get normal speeds if I used a CF wireless card, correct? Or no?
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05-21-2004, 12:19 AM
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Ponderer
Join Date: Feb 2004
Posts: 50
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wow, tungsten C achieved 3 times better results then the best PPC.
actually on my UX50 I get around 250 KB/sec when using VFSFTP+
btw UX50 uses SyChip wifi chip used in the SD card :-) it's the same one :-)
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05-21-2004, 12:22 AM
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Editor Emeritus
Join Date: Aug 2006
Posts: 15,171
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You know, I was reading this and wondered if PIE could also be part of the problem. Has anyone else FTPed large files with a different program?
Nevertheless, I hope OEMs start to realize that as the rest of the device gets faster, this is something they need to optimize.
--janak
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05-21-2004, 12:24 AM
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Intellectual
Join Date: Dec 2003
Posts: 217
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This just goes to show that when Palm does something, they do it right.
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05-21-2004, 12:24 AM
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Editor Emeritus
Join Date: Aug 2006
Posts: 15,171
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Quote:
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Originally Posted by mscdex
So this article only refers to using the SD Wireless card right? I'd get normal speeds if I used a CF wireless card, correct? Or no?
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CF may be faster, but it's not clear how it'll compare to the devices reviewed -- one of the was an Asus A716 with built-in WiFi.
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Originally Posted by c3b82
This just goes to show that when Palm does something, they do it right.
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Generic assertions like this aren't really productive. :? I hardly think things like the PalmOS category/memo pad limits were "done right" to start with. But before we go any further: let's avoid a generic PalmOS-Pocket PC flame war in here.
--janak
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05-21-2004, 12:29 AM
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Intellectual
Join Date: Dec 2003
Posts: 217
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Quote:
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Originally Posted by Janak Parekh
Quote:
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Originally Posted by c3b82
This just goes to show that when Palm does something, they do it right.
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Generic assertions like this aren't really productive. :? I hardly think things like the PalmOS category/memo pad limits were "done right" to start with. But before we go any further: let's avoid a generic PalmOS-Pocket PC flame war in here |
OK, let's keep it specific to the thread.
This just goes to show that when Palm does WiFi, they do it right.
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05-21-2004, 12:36 AM
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Ponderer
Join Date: Oct 2003
Posts: 71
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Oh man Hp took a big hit on that chart.. :lol:
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05-21-2004, 12:36 AM
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Editor Emeritus
Join Date: Aug 2006
Posts: 15,171
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Quote:
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Originally Posted by c38b2
This just goes to show that when Palm does WiFi, they do it right.
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OK, I'll allow that -- maybe. :lol: Now, what I want to know is why they haven't released a WiFi device since... I've heard that the T|C's WiFi power management is second to none, and that the amount of useable WiFi surfing time trumps any other device out there, including both other Palm and Pocket PC OEMs.
--janak
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05-21-2004, 12:42 AM
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Thinker
Join Date: Apr 2002
Posts: 437
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Quote:
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Originally Posted by c38b2
OK, let's keep it specific to the thread.
This just goes to show that when Palm does WiFi, they do it right.
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I don't want to disagree with you but I'm not necessarily agreeing with you either.
Though the article goes in depth to some degree, this is not anywhere near a full comparison between Palm OS and Pocket PC.
One Palm OS device was used, and three Pocket PCs were used.
The Tungsten could possibly just be the fastest Palm OS device for WiFi. Who knows whether the other PalmOS devices are on the same level with Pocket PC?
For that matter, who knows whether other Pocket PCs would be faster? Maybe the HP iPAQ H5555, the Dell Axim X3i, or Toshiba e800 would have surpassed the Tungsten if they were used in the article.
Sorry c38b2, but all that was said to come to this point. Phrases like...
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Originally Posted by c38b2
This just goes to show that when Palm does WiFi, they do it right.
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...at this point are just acting as flame bait.
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