The other linux box with SCST in fileio what are the performance reads and what is it and was this tested on the same system and can we get the hdparm from there logs with this box.
Is the linux box 6bit mode what are the specs....

I believe this might be isolated as I dont have older systems to test with. Can you test with DSS V6 Trial version?

Also look at the dmesg logs to see if we can see anything that could possibly be going on.