Recently my HDD stopped showing up. That wasn't really a problem as I have only been playing GTA V which is on my SSD so I didn't notice it was missing. Untill my system started hanging. I troubleshooted till I found out that when the HDD is plugged in it makes Windows hang at bootup and shutdown. Unplugging it immedtialy fixes the problem.
Seagate does not botch their diagnostic software to say a disk is good when it really isn't. Their main goal with this is to know for sure the test results given are accurate for their drives. This saves Seagate money in the long run. Seagate will give you a much easier time in the RMA process when you say "SeaTools gives me this error code." as opposed to "Frank's Red Hot drive diagnostics gives me this error."
Sure use what ever you want. If you want warranty replacement, it makes it much easier to put the error code that Seagate SeaTools gives you on the RMA form. I have sent RMAs to Seagate going on 50 times now (this is why I no longer use Seagate). If you don't plan on an RMA, use what ever you like.
The drive is not showing up anymore so running a diagnostics tool is impossible. I thought HDDs showed signs when they were dying. This just kinda happened over night.
I totally forgot about the 8gb of flash. I'm going to write to Seagate and find out if they might know what is going on. Luckily I recently copied all of my pictures to my SSD. Although all of my Shadowplay clips are probably gone if the data can't be recovered.
Its a hybrid drive.. its not the controller its actually the flash that has died... the early to mid time revisions had very bad NAND in terms of long term reliability