Email sync
I use my handheld for email all the time. Without a wireless connection, it's impossible to send and receive email on the fly, but you can download email from your inbox or other folders, reply to it, compose new messages, and upload them to your outbox with every hotsync. For the email sync benchmark, I tagged 20 messages as unread in five different folders, giving me a total of 100 unread messages. Using the Intellisync 3.6 conduit with Outlook 2000 set to download all unread messages, I timed hotsync operations for the same 100 unread email messages for both USB and serial. For this and all subsequent tests, the AvantGo sync was disabled to completely remove the PC's internet connection as a variable.

The USB interface performs admirably here, besting the serial connection by almost five minutes. The USB cradle ends up being 4.3 times faster than its serial counterpart, and finally reaches Handspring's advertised 4X speed advantage. While 100 emails is more than I'd usually sync—a lot more—the emails only added 475K to the Visor's memory, dropping the free space from 41.1% to 35.3%. Now USB has a much fatter pipe, but there's something else going on here, because 475k isn't a hell of a lot to be passing down that pipe.

The hotsync process doesn't just dump files onto the Visor; it synchronizes them with the Visor's mail database and converts them into a format that the mail software can understand. The email sync represents 100 files that not only must be converted, but also must be integrated with a Palm database. Since any conversion processing should be independent of the syncing interface used, the slowdown shown by the serial cradle probably has a lot to do with how the files are transferred. I can only conclude that each email is being processed and sent individually. Instead of having one transfer of 100 emails, there are 100 separate transfers. USB has an obvious edge here, as it's able to quickly start and get through small transfers while the serial connection takes significantly longer to get wound up and through the numerous, small transfers.

Etext installation
One of the best things about the Visor (and handhelds in general) is the ability to store etexts for your reading pleasure. Etexts are not only great to read, they also make a good benchmarking tool, since they're generally a single, large file. For this benchmark, I installed a 1,924k etext on to the Visor. Since the original format for etexts is plain text, there was some conversion that needed to be done to turn the file into a Palm document that the Visor can read. That conversion is done on the PC before any syncing takes place, though, and therefore doesn't have any impact on the results.

Wow, USB really ripped through the etext, beating the serial interface by a whopping eighteen minutes. It took a while with both interfaces, but the USB cradle was able to complete the task 5.15 times faster than the serial connection. While we saw USB take a big lead with the email sync, this win for USB comes under totally different conditions. Since all the processing to get the etext into the Palm document format is done on the PC, this test is all about how fat the pipe is.

So why does USB do so well in comparison to other tests we've run thus far? This is about the simplest benchmark testing the raw speed of the syncing interface. Because we're just dumping a document file on to the Visor, there's really no synchronization; it's just a straight file copy. Also, unlike AvantGo and email syncs which deal with multiple pages or emails, this is a single file big enough to let both interfaces wind up to their top speeds. As you can see, USB is faster than the advertised 4X serial speed for large single file transfers.