I just bought an i5 NUC 2 days ago, 8Gb ram. Tested normal HDD at the shop and everything ok.
At home, updated to latest BIOS (WYLPT10H.86A), I tried with my SATA OWC Extreme Pro 6G 240GB SSD, and it is not detected. Tried again with other SATA SSD, here is the result:-
1) OWC Extreme Pro 6G 240GB = not detected
2) Intel 520 480GB = not detected
3) Crucial M550 1TB = detected after 10 sec delay at POST
4) Crucial M500 960GB = detected immediately, fast and furious.
5) Samsung 840 Evo 1TB (mSATA) = detected immediately, fast and furious.
Out of 4pcs 2.5" SSD, only Crucial M500 is working flawlessly. The rest is having problem of slow detection or no detection at all.
This is annoying, and after trying around, i found the real problem of this SSD issue on all intel NUC, which later i found out many people is also facing:-
The short SATA cable in the NUC is NON_STANDARD type. The connector is standard, but the pin arrangement is not. Try this, take out that short NUC SATA cable and install it on a normal PC - NONE WILL WORK. Next test, replace the short NUC SATA cable with a normal SATA cable - again NONE WILL WORK. Intel has changed the cable standard, and then use the female SATA connector in the NUC to revert it back to "normal". By logic this should work; but in reality, many SSD suffer from this.
However, a good news is that the mainboard of the NUC has no problem, i try remove the NUC hdd caddy, replace with normal SATA data cable and an external SATA power cable to power the the SSDs. Guess what, ALL SSDs are detected and running perfectly !!
So the problem here is very clearly, not at the mainboard, but starts from the non-standard SATA cable until the female SATA slot connecting to the SSD. I don't know how intel is going to do about this, even their own 520 SSD is not detected. BIOS update may help, but intel has to test all SSD in the world to guarantee the compatibility.
From our consumer part who is tired of the SSD issue, besides waiting for the mercy of intel, the immediate way to overcome this is to remove the default cables + hdd caddy and replace with normal SATA data + power cable. normal SATA data cable is easy, but the power cable may not, you need to find both end female slot power cable, which is almost non-existent. One possible solution is to get the 1 male to 2x female sata power cable splitter and just use the 2x female end. Best if you can get someone to custom made for you a short female - female cable.