Aurender N100 internal hard drive or USB external drive?

I own one of the rare breeds of Aurender N100 variants that did NOT come from the factory with any internal hard drive storage, it is the same as the N100H in every other aspect.
Right now I have a 4tb WD HDD connected in the rear of it by USB which is fully accessible from the Conductor app.

I guess two questions really....

1/ Would I truly notice any difference in SQ if I went ahead and installed an internal hard drive vs my present usage of an external USB hard drive.

2/ If I went ahead and installed an internal hard drive, what model of hard drive is fully compatible with the N100, or does it really not matter? Or are there levels of HDD drives? Is SSD better than HDD? Are there levels of SSD?

Guess thats more than two questions but you get my quandary.
Seriously this stuff keeps me awake at night.........

That’s way too many questions...just kidding. Looks like you got the N100SC model.
1. I would say yes, you should hear uptick in SQ. Based on my experience with head to head comparisons between Vault and Aurender playback from their respective internal drives. The music files stored on sounds fuller, detailed and smooth compared to those on Vault. The music stored on Vault drive sounds lifeless. There is a considerable amount of loss in high fidelity.

2a. What drive model, I would ask Aurender support team for recommendation.

2b. SSD better than HDD...Yes, here is why; by caching songs to the SDD for playback, it eliminates any sound quality degradation and even drop outs due to a non-optimal network connection from for example, a NAS drive. Playback from SSD also minimizes wear and tear on the HDD drive as after loading to the caching drive, the HDD goes idle.

With a internal drive, you’re also shortening the path and eliminating possibilities of external interferences between two components.
Great article Anwar, thanks!

Sounds like due to the way Aurender caches all music queued up to play onto its internal ssd it might not be as crucial for where the hard drive resides as it might be otherwise.

However I still might prefer to install an internal HDD just to tidy things up a little.
Internally, you have less of an issue with more power supplies to pollute your AC.

SSD is best, but you don't need top of the line. 2 year old SSD's have plenty of throughput.  They have instant, random access, and no motors to spin up/down.

I only have about ~ 200 GB of music at home, I keep it on a thumb drive attached to my Roon server. Technically slow as can be, works fine.

Heard back from Ari at Aurender customer support.

You pays your money and takes your choice apparently.

Any brand off HDD or SSD was his reply although he did say he preferred Samsung for SSD and Seagate for HDD.

I’ve had good luck with Samsung, crucial and WD ssds, according to their website it needs to be a SATA SSD 2.5/ 7mm. There’s 3 speeds I, II , III get the III it will run at whatever your streamer accepts and that’s the fastest and most common now. If you decide on a HHD same deal 2.5/7mm need to watch those some laptop drives are 9mm.
Thanks for the additional information of speed of drives.
If going to do it probably not worth skimping so do it right first time.

The speed would be dictated by the streamer connection most likely it's either SATA II or SATA III either one would be plenty fast for audio. Main thing is the interface of SATA 2.5/7mm there are a lot of different ones. 
Good comments by @Djones51.

I believe that a 4 TB HDD in a 2.5 inch/7 mm form factor is something that probably doesn’t exist, at least from a quality manufacturer.

Although I have no experience with Aurender products I don’t think you could go wrong with a 4 TB Samsung SSD, especially the "EVO" version. The somewhat less expensive "QVO" version just comes with a 3 year warranty, as opposed to the 5 year warranty of the EVO. Also, while it may not matter the QVO is rated for considerably fewer lifetime writes than the EVO (1440 TB vs. 2400 TB).

Unfortunately, though, the Samsung 4 TB EVO SSD costs $600 at B&H or Newegg, my go-to places for such things.

Best regards,
-- Al

It looks like you are correct on there not being a 4tb hdd in 2.5 and 7mm height format, largest would be 2tb.
I have found a few pre owned Samsung 4tb ssd in 2.5 and 7mm height on Fleabay between 350 and 400.
Might be my route as I have not much intention to perform many writes, just my initial copy and a few updates when/if I add more albums digitally.
Thanks to all!
I have a Sony HAP-Z1ES. It comes with a 1TB HDD from factory. It wasn't long before I had that filled and had to replace it with a 2TB HDD. Later on, I read somewhere that replacing the HDD with an SSD would improve the sound quality. Of course I had to try it. I found a 2TB Micron SSD for cheap on Ebay. Expecting a minor improvement in sound quality, if any, I fired it up and was immediately blown away. Not a minor improvement, but a large one. I was up half the night listening to all the songs I was familiar with to hear the difference it made. Fast forward to adding an external DAC, again being blown away, way more than the SSD blown away. This was a new level of blown away. A little while after that I started thinking 'if a DAC made that much difference, how much would a front end make?'. Get rid of the Sony and get a higher end server. After a lot of looking, I found a good deal on a demo N100H. An item I had seen in my local HiFi shop of choice but never thought I would ever be able to afford. Before even paying for the unit, the gears in my head were upgrading the HDD to an SSD. It made a huge difference in the Sony so I had to try it in the Aurender. I then started reading the forums and learned how the Aurenders cache the data to an SSD prior to serving. That did not deter me. If bits can be disturbed traveling from an HDD to the electronics then bits can be disturbed traveling from an HDD to the cache SSD. I will make this upgrade. Oh yes. After finding the SSDs I wanted, paying lots of money for them, and pulling my hair out for days trying to get them to work in my N100H, I fired it up and listened. Does it sound better? The delay in swapping everything out and the headaches trying to get it to work had muddled my memory of the HDD sound so I could not say for sure one way or the other, although I think it did, but not as much as with the Sony. Regardless if it did or not, I hate mechanical HDDs and would have done the swap even if I knew it would make no difference in sound quality. I get peace knowing that I have good quality SSDs in there shuffling my bits around and serving them up to my DAC. I'm loving the sound of this thing. 

If interested, here are some photos of it after the upgrade. As the photos show, I used Samsung 860 EVO drives. 500GB for the cache, 4TB for the storage. 500GB is overkill for the cache but it was all I could find in an 860 EVO. I used a Silverstone thin double right angle SATA cable and created my own SATA power harness from an old ATX power supply. The harness is inside a channel I designed and 3D printed to keep it away from the other electronics. I could have used the harness that was already in there for the HDD but I didn't like it sitting so close to the USB circuitry. I'm no engineer but that just didn't look like a good idea to me. I also used double sided tape to keep the SATA data cable away from the board and against the outer casing.
That is strange.  I replaced the 1TB HDD in my Sony HAPZ1ES with a 2TB SSD and heard no difference in sound quality.  

Hi rcb3n474! I'm not a computer master but good enought to disamble a computer and putting back together knowing what am I doing! My problem is I'm not very familiar with linux. You said it was very difficult to make it work! Can you explain what was your way to make it? Did you clone the hdds? And what kind of partitions did you used? I intend to buy a second hand n100h but 2terra it is not enough to me so I need to know how difficult is to change to a larger hdd! Thank you!

Buy the Samsung EVO 4TB SSD. Put it into the tray at the rear and using the Aurender app format it. Then plug in your HDD with your stored music and copy it to the SSD using the Aurender app. Easy. 10%+ improvement in SQ.