As stated WIE is not a good a good bench mark, terrible would be better. But it does provide a good indication of working, ie if you get a score of 4.2 for your HDD and eveybody else is getting 5.9 you have a problem.
On that same note: there is not a big diff beweenr raid0 and a Non raid0 in overall performance. Raid0 improves only Sequencial read and writes, it does little, to nothing, to improve the more important small file random reads and writes, and does not improve Acess time (unless short stroked). The best SSD only scores a 7.9 and it is at min 40->50 times faster than a HDD. So even if a raid0 HDD was 20% faster than a non-raid0, that's just to small of a change (20% x 2/40 is only .01) ie HDD is 5.85 = 5.9 and raid0 is 5.96, still 5.9.