I own a Dell Precision T1600. I recently purchased 16gb of used ECC RAM for my precision, seeing that it supported up to 16gb of ECC RAM. It was 30$ USD so, a pretty good deal.

http://www.dell.com/downloads/global/products/precn/en/precision-t1600-spec-sheet.pdf

http://www.ebay.com/itm/Pair-of-Samsung-8Gb-2Rx4-PC3L-10600R-ECC-M393B1K70CH0-YH9-/321930449871?nma=true&si=fg3oJjujt%252Fzha1ZSbLlkx1HGXMA%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

I received the RAM today and plugged them both into my mother board. The mother board beeped twice then beeped in sets of three. It did not turn off but nothing was displayed on my monitor (no start-up, no bios, etc.). I then plugged in my original RAM along with the two new ones. It turned on and worked as expected. I then ran a system & components scan to check if everything (including the new RAM) was working as it should be. Everything checked off as 100%. Entering my system settings I found that it only recognized 8gb of installed memory. My motherboard supports ECC RAM and the components check resulted in no error. I'm certain it is compatible with 8gb sticks of ECC RAM because I've seen them sold for the T1600.

http://www.amazon.com/Memory-Precision-Workstation-Black-Diamond/dp/B009TI53BA

I've also checked my bios to see if ECC compatibility is turned on, but I couldn't find any ECC related sections of my bios.

 So my question is, what the heck is wrong with my setup?! Is my RAM broken? Is my motherboard lying to me and actually not compatible? Has my mother board turned off the compatibility for ECC RAM? Is there a way to turn it on from somewhere other than the bios?  Please inform me.