Yup, I have the DS411slim running with 3.5" drives right now.
The cage and power supply got here early and I just finished assembling everything. It actually works pretty well if you don't mind the mess of wires hanging out the back. It's definitely not portable, but like I said I was just gonna shove it under the desk and forget about it. The drives are a little noisier with only the thin aluminum wall supporting them, and the fan is a little noisier than I would have liked. I'm gonna see about wrapping the whole thing in some insulation or something to cut down the drive noise, and undervolt the fan to cut down its RPM and noise. Maybe snip the wires to the annoying blue LEDs while I'm at it.
If anyone else is thinking of trying this, I'd recommend you get SATA power+data cable extenders + SATA data cable extenders. The SATA data-only extenders have little notches on the side which you have to cut off, and they don't grip into the SATA ports in the NAS very well. There's a danger they could fall out from a little jostling, forcing a rebuild of your RAID array. The single-piece power+data extenders plug in just like a HDD and grip really well. So I have NAS -> SATA power+data extender -> SATA data extender -> HDD. I hope the combined 38" of data cable length isn't hurting performance. If I had it to do over again, I'd go with shorter cables to keep things a little neater.
The picoPSU worked as expected. I'm not sure if 60W is enough to simultaneously power up four 3.5" drives. They're supposed to need 20-30 W each on spin-up. But I noticed that the NAS powers up the drives one after the other, so theoretically all four drives should not be drawing peak power simultaneously. 3.5" HDDs typically only draw about 10 W max once spun up, so 60W should be plenty during normal use.
I did have to short pins 14 and 15 on the picoPSU with a paper clip to get it to power up (normally these pins connect to the power switch on your computer). On a normal power supply, the wires to these pins are colored green (signal) and black (ground). The picoPSU doesn't have cables so I kinda had to guess. Fortunately, the symmetric pins (16 and 17) are both ground so there was no harm in guessing wrong.
Enough of the construction details. Here's what you've been waiting for - performance:
Right now my DS411slim is hooked up to two Seagate 1.5 TB 7200 RPM ST31500341AS 3.5" drives. Yes, the notorious click of death drives which ruined Seagate's reputation. I made sure to flash them with the firmware fix before using them, and they've served me fine for 2 years. I allocated 100 GB of the NAS to iSCSI and mapped that as a local drive, then ran CrystalDiskMark on it. About 1.2 TB of the 1.36 TB is full, so it's possible this is only reflecting performance on a section of the disks, rather than an average. Jumbo frames are
off.
The 4k reads could be a little better, but otherwise this is pretty much indistinguishable from any of my older HDDs mounted locally. I'm happy with it. Significantly better than the sequential 40 MB/s reads and 20-30 MB/s writes I was reading from the DS411j reviews. The drives are reporting 33C and 34C temps, so no problems on that end.
I'm gonna clear the data off the 2.5" 1.5 TB drive, add it to the SHR array, then see if performance changes. Then decide if I should stick with 3.5" drives or can live with 2.5" drives. Long-term, when 10 Gbps ethernet is common and 60 MB/s is considered slow, I'd like to transition this to entirely 2.5" drives for portability and maybe use it as a media server. But for now, this is fine.
