My sata cables always needs to be changed

The most obvious answer would be to use higher quality cables. Run an e-Bay search within the Computer section for "SATA cable" then sort the search into "Price highest first". I just did and found some at £40 which surprised me a bit. Ignore the Apple ones - they may not work in a PC.

Just buy one to experiment with in case this advice is total rubbish.  

i've never heard of such a thing. i've used nothing but the free cables which came with all of my pc parts without a hitch. performance on day 1 is similar to performance after a few years at least in terms of cables.

i'm not sure of the brand but the ones i use all came with my top of the line asus and dfi motherboards so i'm sure they are a bit better than low-end junk cables but still i dont think they are expensive by any means.

i agree, dont use junk cables. this doesnt mean however that you need to pay $40 each for one. buy from a well known brand and you should be fine. if you still have issues then perhaps there is a problem elsewhere. some component or software could be to blame instead of the cables. i'm not sure why a new cable would affect performance but sometimes pc problems are perplexing indeed.....