Actually had it set to 1024 block size, I thought changing it to 512 would ruin my partitions but it didn't happen 
Had SFS on this hdd before, the speed increase when opening a drawer is very noticeable with PFS3
check with Icon Information (or any other tool) and you will see that is using 512 bytes even if you set 1024 in HDToolbox (or what you have used for partitioning)