A typical consumer hard drive is going to last about 5 years, maybe more but it will wear just from existing. If you wrote 16GB to it a month that wont be a challenge for it.

The SSD however will be specified on a life of how many writes it can do. For example a 990 Pro from Samsung will have a specified life of 1200TB. That is about 76,800 months of operation at 16GB, this is not only not a challenging workload for an SSD but you have 8 of them so 8 * 76800 months of operation on average.

I have SSDs that are quite old, my original Intel 80GB G1 still works and still has 80% of its life left but its utterly obsolete as its too small to be useful and 500MB/s on SATA is a bit dated. All the OCZ SSDs are dead long ago but the Crucial M4 is still trucking along and its 512GB so still useful enough as is the Western Digital 1TB. I have barely scratched the surface of their usage life despite writing 35TB on them they still have 95% life over 42,000 hours of operation.

So at 16GB writes monthly they are going to last as long as the silicon and PCB lasts, which if made well could be decades. They will certainly become obsolete in speed and size more than likely rather than dying.