2-4 MB/sec. from a NTFS formatted drive plugged into a Windows computer seems very slow to me, and in the past I’ve used a 3rd party add-on to enable writing to NTFS disks without noticing any problems. Assuming there’s no other bottleneck between your computers and the My Cloud–like an iffy Wi-Fi signal, for example, or an older router that doesn’t support gigabit Ethernet, etc.–I think your results actually *do* suggest the problem lies with the NAS.
When I first copied my data to my My Cloud, everything became excruciatingly slow very quickly, and within a few hours the drive was thrashing so hard, i thought it might wobble itself off the shelf… Everything changed completely as soon as I disabled the “wdmcserverd” and “wdphotomergerd” daemons after stumbling upon this thread:
Now I don’t know if that’s what’s happening in your case. All I can say is that after switching off DNLA and iTunes serving from the drive’s dashboard, and then entering via SSH those four short command line instructions–2 to turn off the daemons, another 2 to prevent them from starting again upon reboot (I opted for the update-rc.d command rather than the alternative suggested in the thread of fiddling with permissions using chmod)–doing that made the drive behave the way it it’s supposed to: fast, quiet, reliable. What I gave up by disabling those, I’m not sure, but since I do all my media streaming via iTunes itself (Home Sharing), I had zero use for any of the drive’s built-in media serving features. If your data has a lot of photos, and it doesn’t matter where (because in my case they were buried among my iTunes tracks as album art), the WD NAS will not only “index” them, but also generate thumbnails for every single one. It’s completely indiscriminate as to what it thumbnails: if it’s an image–anywhere–it gets thumbnailed. My hunch is that the drives processors are plenty adequate for running a reliable and quick consumer network drive. If you happen to have a lot of photos in your data, like album artwork or a photo library or two, then then they maniacally start thumbnailing every bleeping image they find… I just don’t believe they have anywhere near the grunt to do that kind of thing. Certainly not with large volumes of media, which–ironically–is why many people buy the drive for in the first place!
Again, this may not have anything to do with your situation at all. But I wouldn’t settle on any conclusion re. the drive’s functionality until you’ve disabled those 2 daemons and tried it that way first.
