If anyone knows, this would be great.

1. Can I plug a large (~100GB) USB-based SSD into one of the USB ports and will it read properly?  Presume I have on that disk the following sort of hierarchy of directories and files:

Artist / Album / xx - Track Name.ext

The actual music files will be either .FLAC or .MP3 extensions.

Will these units (1) correctly accept such a device as storage and read it, (2) not take an eternity on each power on to do so (that is, they keep track of the disk ID and don't have to re-index if the same one is still connected) and (3) CORRECTLY SORT THE SONGS?  I've had problems with some other brands that I've tried this with.  The latter is a huge issue if it decides it's going to read ID3 tags, ignore the track number, and ignore the filename!  That's two ordering systems that these units ignore (and there are multiple offenders, by the way); some are even worse in that they use the actual inode (directory entry!) order to sort on which, unless you're very careful and never delete and replace a file, will bite you hard and makes changing anything on the storage medium impossible over time.

In each folder (Album) there may also be an album art file.  Will it display on the head unit?

2. Does the above apply to an SD card inserted in the unit too?

I like these units conceptually but I have a VERY LARGE music collection.  If I want FLAC files it will NOT fit on an SD card.  Not even a large SD card.  It WILL fit on a SSD in a USB enclosure, which will work on even a 500ma USB power-limited port (being an SSD.)

But if the unit can't handle this, or worse, scrambles the order of the music when I select an album to play....... then it's worth zero.

There are no car audio shops around here that have these units in their building so I can't grab a USB-cased SSD and go try it.  Thus, the questions.

Please tell me Pioneer didn't make something that is less capable than my 10+ year old Phatbox!

I think there was a member here that did add a usb drive and it worked. as to for how large i dont know. Yes when plugged in you will see the folders in alphabetical order. Album art will show on the unit.

Folders in alphabetical order is good (if you can drill into them as you'd expect) -- but how about the song order?  There's a comment that prompted this that the unit was reading the ID3 tags and sorting alphabetically on THAT!  (right below this message in the list)

That will cause every album to play in the wrong order....

I use an 80gb intel ssd, and it works great. I have the 4000nex.

Thank you Joe.... that's exactly what I intend to do (but with a 120Gb SSD; I have an extra Vertex laying around in an external USB enclosure...)

So just to be clear with the music on an SSD, say, "The Wall", if you play that album where you dumped the files it sorts and plays by track number so the songs are in original-album order (without having to create a separate play list PER ALBUM) -- yes?

Can the unit handle a NTFS-formatted device (FAT doesn't work for devices beyond ~100GB, and most media devices won't read multiple partitions, so if you have a "large" device you're screwed as you are forced to format it in either exFAT (which these units won't read) or NTFS (which they ALSO won't read!)

Last question -- how is the delay between tracks?  The Phatbox is capable of "stitching"; that is, it pre-reads the next file in series so the audio is SEAMLESS, which is important for albums such as much of Pink Floyd, Genesis, a fair bit of classical music and others.  I know these units don't do that (although they damn well should; this is 2014!) but they don't -- how long is the delay between songs (e.g. gap)?

I like to know this also, but surely having a 120gb ipod classic would do the same job unless you don't like  apple products, which is ok, some don't.

Koush

"Go buy a fruit product!"

No.

(Never mind the reading issue -- FLAC, which is what makes this series of decks interesting to me in the first place.)

i just copied artists in no order to my hard drive, the head unit sorts  everything however you want. all alphabetically, whether it is by artist, album, songs, genre. If i feel like a certain artist, i will go to that artist, it will list albums, or hit all, and it will show all songs. I happen to shuffle all my songs usually. It will take a few minutes to read the whole drive, initially. After that, it takes no time at all. It will remember where you left off, and start playing at that point. If the  songs are ripped say from a cd, it will list them in correct order. there is very little lag if any on the sad, nowhere near what it would be if it was spinning disc. According to the operators manual, it can read ntfs, fat16, or fat32. I don't recall how mine is formatted. It will not read a disc that is partitioned. 

I personally, prefer the ssd over the iPod. you can get a 250 gb for less than 150.00 on ebay. And get external enclosure for less than 20.00. comes with usb cord. No expensive apple cables needed or anything else. I am using an intel X-25m that is several years old i had in an older dell m1530. I got a samsung 830 pro 240 gb, intel 530 series 480gb, in my MacMini, and my Macbook pro, and both of them are extremely fast. You don't have to buy the fastest or most expensive ssd for these head units, all are going to be so much faster than a spinning disc, and you don't have to worry about vibration, or bouncing around like you would spinning disc. Plus they don't use near the power, 2 watts compared to 6 watts. Kind of a no brainer, now that ssd's are finally affordable. I opted for the 16gb iPhone 5s, because all my songs are also in the cloud, so to speak. I have 140 gb of songs on each of my computers, so copying them onto a ssd is quite easy. Both of my son's rap crap is also stored on my computer, but not on my trucks ssd. I can only say this has to be the most awesome setup i have ever seen in a vehicle. Back in the early 2000's i had pioneer super tuner with 12 cd changer, but nothing compared to this.

I think I'm gonna load up a drive and check it out, see how fast it is

Tekki, give us a report on what you experience  please.

Well the NEX line supports the NTFS file format which a big boost over previous units that were restricted to FAT32. As such I'm certain that it could handle larger libraries without a problem.