slow usb-c transfer speeds, reliability and Files app bugs, iPad OS, iPad Pro 2018
I've been experiencing unexpected and buggy behaviour of Files app when copying data from and to an external storage media.
iPad OS 13.1.1 and 13.1.2
Files app bugs:
- ExFAT formatted drives (both ssd and hdd) cause problems: files copied to external media not visible in Files app. Files app hangs and refuses to recognize drive after leaving current directory while file is being copied
- usually SLOW (10-15 MB/s) transfer speed when copying files from iPAD to external media - occurrs for SSDs, HDDs, SD cards, thumb drives, regardless of connection method, file size, file system (exFAT, APFS, OSX extended journaled). Same setups for all Macbook pros I have at hand exhibit transfer speeds reaching max specs for the devices. (all above 100 MB/s) - I can provide more details in subsequent posts.
- Frequent errors when copying large folders and files (5 GB and heavier) - files not visible after copy process or drive disconnects during transfer (probably related to exFAT or power hungry devices)
- Transfer progress bar inaccurate (finishes at half-revolution around the circle)
- Transfer progress bar visible only after changing view mode
- Multiple instances of a copied file listed during copy process (might be expected as one could be a partial file, but looks confusing)
- Initiating copy - paste from long press menu (as opposed to drag and drop) operation often does not provide visual feedback of the operation taking place - file name and progress bar visible only after view change.
- drag and drop copy-pase often drops the file in the last folder within the active directory, and not the active directory itself - minor annoyance for casual use, but for work related issues this can be a major workflow disrupting problem.
General related issues:
- For iPad Pro 11 2018 - Plugging in drives rated at 1,4A @ 5V (example: samsung 850 ssd in external usb-c enclosure) causes system crash during file transfer, without the "usb device requires too much power" message - iPad turns off and then restarts by itself. Does anyone know the recommended Watt/Amp rating for iPad Pro 2018 external USB devices?
- Inconsistent file transfer speed via usb-c FROM external media to iPad- especially SD cards (connected via Apple USB-C to USB A dongle or directly to usb-c port)
Regarding transfer speed for iPad Pro 2018:
I'd be grateful for a REAL LIFE max expected transfer speed, not the USB 3.1 spec.
Case in point:
Same sandisk extreme pro SD card connected via dedicated sandisk reader and Apple USB-C to USB-A dongle, transferring raw photos of about 30-50MB each. (I've checked batches of 4, 10 and 50 gigs of images)
- transfer speeds with usb-c equipped MacBook Pros basically max out the card at 160 MB/s
- transfer speeds with iPad Pros 2018 (checked a few devices) vary from 60 to a bit over 100 MB/s
I observed similar behaviour for other media, such as SSDs, HDDs and thumbdrives
iPad Pro 11-inch Wi-Fi
