Wd raptor 36g 8mb cache

hi guys

I found this drive for 10e and i bought it(out of curiosity mostly because i ve never used a 10k rpm hd before) I installed the o.s on it, leaving a samsung ecogreen 5400rpm for storage.
Hd tune shows 80mb max for wd and 100mb for samsung but the wd has more than half access time (3 vs 8 ms)
3dmark05 (with exactly the same os and programs running in backround) gave the wd almost +500 points "overall" but also +1200 points "cpu score"
System is more responsive now especially in install/uninstall and winrar(or at least it seems to me like it is!?)
Do you think is a good idea keeping the wd for o.s (considering the fact that is a bit noizy compared to the samsung) or the extra 3dmark05 performance is too small in order to counterbalance the extra noise.

Thanks in advance and sorry for any grammar mistake

What are the average throughput rate on the drives? Are you saying the access time is 3ms on the WD and 8ms on the Samsung?

Since the Raptor has a better access time and throughput rate, I'd say it would be better for the OS and apps. Plus, you say you notice that the raptor is faster. The only problem is that it is really small. If the size, heat, and noise are not a problem for you, it sounds like it's better. But it's really up to you to weigh the pros and cons.