This adapter SATA -> IDE are perfectly filled role. In my case, the idea was to be able to connect SATA hard disk of a failed PC IDE external hard drive case in order to recover the disk data to be able to transfer them to another PC. Tested for several hours, this small adapter works perfectly well. I can not give a figure as to its transfer speed because the SATA drive that I used is an old Western Digital 40GB that is not what there is faster. But he did not seem to be any particular slowness compared to the use of the disc when it was directly connected to the PC via SATA.
