Data recovery success rates are not what they appear to be. Total data recovery success rates can be defined as:
Some data recovery companies that promote a single figure ‘success rate’, maximise that success rate figure by leaving out the jobs that they failed to recover from.
Here is how they do it
The number one cause of failure of computer Hard Disk Drives (HDDs) is where the surface of the spinning data disk (platter) is damaged by what is known as a head crash, where the read/write head(s) comes in contact with the spinning platter. The severity of the damage varies and in most cases the severity of the damage means the data is unrecoverable.
This is where the manipulation of the recovery rate figure starts. If the HDD arrives at the data recovery company with this type of failure and there is nothing they can do to recover the data they don’t include it in the success rate calculations.
Note: not all HDDs with head crash damage are unrecoverable. Highly skilled data recovery companies can recover from this type of damage. The investment in a well-equipped and costly clean room is required so that the HDD can be taken apart in a controlled clean environment, in order to prevent further damage being unintentionally caused. It is unusual for these conditions to be met to the standards required of accreditation required in the UK.
And in brief, here’s another way the figures can be manipulated
A data recovery company can define a successful recovery as being able to read any amount of data from the failed HDD, this could be much less than 0.1% of the total storage area and not even contain any of the lost files. Can this truthfully be described as a success when the customer is not going to want to pay for that data?
In reality, the success of a particular data recovery depends on a broad and complex range of factors, including difficulty of recoveries undertaken, the cause of the data loss and the storage environment on which the data is stored. For example, it is easy to achieve a very high success rate for standard hard disks, but difficult to achieve a high success rate for more complex or unique recovery jobs.