How much readable blocks last last longer than writable ones?

Question

Let's say I have some data on HDD that being only viewed. How long those areas of HDD will last in comparison to those which gonna be constantly overwritten ?

Answer 1

I believe a more appropriate way of asking this question might be "How long does bit rot take to set in".

The answer is "It entirely depends entirely on the disk", however in reality the hard drive is orders of magnitude more likely to fail from old age then for bit rot to occur.

On any decent hard drive in a normal operating environment, bitrot should not set in for many years - typically longer then the 1-5 year warranty of the drives. While it certainly does happen, for a home user its more of a theoretical then real problem.

Answer 2

As mentioned here:
"Most sources state that permanent magnets lose their magnetic field strength at a rate of 1% per year. Assuming this is valid, after ~69 years, we can assume that half of the sectors in a hard drive would be corrupted (since they all lost half of their strength by this time). Obviously, this is quite a long time, but this risk is easily mitigated - simply re-write the data to the drive."