I've, along with several other tech writers (see for example THIS) recommended “Phone Disk” and “iExplorer” in several of my articles (see for example THIS). These two apps allow for directly accessing files under not only the media directories, but also any installed AppStore apps, allowing for adding a lot more functionality to, for example, computer emulators available in the AppStore like the PC or the C64 emulators or fixing major bugs (e.g., inability to restart) in programs (see for example my two bugfixes of the third-party apps “EC Player” and “Hard Lines” HERE and HERE, respectively.)
Today, I've decided to provide you with, in addition to the charging Amperage of my previous, dedicated article, some more specific benchmark data on the synchronization / file transfer speed of both Apple's own and (cheap) third-party cables. While I've already mentioned in the comments section Chinese, cheap cables are generally sufficient for synchronization, I wanted to offer some more tangible results.
After realizing all the Apple cables (both the original 3-ft ones and the component video cable) are about 6% faster than the two shorter, Chinese cables I've tested (I'll update this article later with benchmark data on the 10-foot cable) during iTunes File Sharing file transfers, I've re-run the tests with external (non-iTunes) file transfer tools, including both Phone Disk (current, tested version 22.214.171.124 for Mac) and iExplorer (v126.96.36.199 for Mac) – and iFunBox (V0.8.0719 for Mac), in addition. iFunBox is a highly recommended tool on both OS X and Windows, particularly now that its app installer utility has been fixed on the Mac. (Up until now, only the Windows version was capable of installing apps on non-jailbroken devices.) Now, you can install any signed, legally purchased IPA files on any desktop computer, even on ones that are not synchronized to your iDevice. This feature is a REAL killer and highly useful, “thanks” to Apple's overly restrictive approach to app synching via iTunes.
While iExplorer and iFunBox both delivered only slightly worse desktop-to-iDevice file transfer results than iTunes File Sharing itself (while the latter only needs 1m:02s to transfer an 1.7G file to the iPad 3, the two former apps take 1:08 and 1:16, respectively), Phone Disk delivered waaaaaaay worse results: it took almost four times more (4:40) to transfer the same file on my late 2009 17” MBP running Snow Leopard 10.6.8.
I've re-run the tests with an absolutely clean (no previous installs of Phone Disk, unlike on the 17” MBP) early 2010 MBP 13” running Lion 10.7.3 for another file and got very similar results. These are as follows for both reading from and writing to the non-jailbroken (more on JB-related Phone Disk problems later!) iPad 1 (running iOS 5.1) on both MBP's:
Phone Disk: 2:44 (SL) / 2:20 (Lion)
iExplorer: 0:56 (SL) / 0:49 (Lion)
Phone Disk: 1:40 (SL) / 1:37 (Lion)
iExplorer: 1:15 (SL) / 1:08 (Lion)
As you can see, writing with Phone Disk has turned out to be much slower than with iExplorer (or, for that matter, iFunBox / iTunes). Reading is better BUT!
The iDevice-to-Desktop memory usage bug
The latest, current version of Phone Disk is still suffering from the same memory usage bug plaguing the previous versions and applying to both OS X versions.
When you transfer files from the iDevice to your desktop using Phone Disk, it'll allocate RAM memory for the file(s) it transfers. This means if you transfer a 1GByte file from your iPad (for example, a video you've shot), the Phone Disk process will allocate slightly more than 1GB memory for itself. An example Activity Monitor shot showing the memory usage (here, 816 Mbytes) of the utility:
Unfortunately, if you have physically less RAM memory than the (total) size of the files you try to transfer, this will result in your Mac's completely bogging down. Also, Phone Disk doesn't deallocate the memory after having finished any transfers. It's only by manually quitting and restarting it that you can free up memory. All in all, before this bug is fixed, do NOT transfer large (or a lot of small but totalling Gbytes in cumulative size) files from your iDevice with Phone Disk and/or quit it immediately after finishing the transfer!
(Note that I haven't tested the Windows version of the app. All this may only apply to OS X.)
Finally, there is another major problem with the app.
Phone Disk can't transfer huge files to jailbroken devices
If you, for some reason (the above benchmarks show you shouldn't), would still like to use Phone Disk to transfer huge files to your iDevices and they happen to be jailbroken, you'll be surely greeted by an error dialog complaining about the iDevice not having the necessary free storage.
I've thoroughly tested the problem. It's present on both OS X versions (10.6.8 and 10.7.3) I've used. Some figures: I've tested the following jailbroken devices:
iPad 2 5.1.1 with 5.8G free: about 220M can be transferred at most
iPad 3 5.1.1 with 12.8G free: about 900M can be transferred at most
iPhone 3GS 5.1.1 with 27.3G free: about 400M can be transferred at most
This problem doesn't apply to non-jailbroken iDevices, where you can (but, again, shouldn't – other and even free(!) means of file transfers are far faster) transfer even files of Gbytes.
All in all,
for the time being, for transferring large files (or many files totalling Gigabytes in size), use Phone Disk cautiously (or only when it's absolutely necessary) because of the slowness / RAM usage bug / jailbreak bug.
UPDATE (somewhat later): I've also tested the 10-foot cheap Chinese cable. Just like the other, cheap cables, it's about 6% slower, transfer speed-wise, than the factory 3-foot cable of Apple. This is a very good result indeed for such a cheap cable! (The tests have been conducted on two cables. Both delivered the same results.)