Honestly I could rattle offa few tests but ultimately this question is one that begs another question. Why are you wasting valuable time running diagnostics on a cable that costs $.50. In all seriousness if you have any concern with s drive cable, change it and benchmark before and after using any reliable benchmark. If the metrics improve replace the cable, if not look into other potential causes. You will spend hours running proper diags, top quality Sata cables cost $.50 bulk, about $3.00 Retail... Unless you live in Alaska and every computer store North of Washington is out of Sata Cables, you'll waste more time, money and Effort testing the suspect cable than a dozen replacements are worth. It's an efficiency issue.
Try a new cable and compare results, If they're better, keep the new cable, worse switch back and test for other issues, same leave the new one and test for other issues.
Oh sorry I was meant to ask this on Superuser. Can somebody with sufficient reputation migrate this over, please? – netvope – 2011-02-18T04:48:53.463