Flash
Lost in speed
Exactly. If the data1 is overwritten with data2, you will little or zero chance to retrieve data1.Since you have tried multiple softwares, but still in vain, most probably the data has been over-written. Using anymore recovery softwares won't be of much help.
As said above, if the data is of prime importance, give the HDD to a professional recovery company, but even then you need to keep your fingers crossed.