S400, i3-2365M + AMD HD7450M@RM1699[1.8kg], 4GB, 500GB(5400rpm), W7HB
S400, i5-3317U + Intel HD4000 + 24GB mSATA + 500GB(5400rpm)@RM1999[1.8kg], 4GB, W7HB; AMD HD7450M/W8@RM2199
The i3 is sandy bridge (2nd gen), the i5 is ivy bridge (3rd gen) Intel i core CPU.
The i3 is also an M(obile) CPU, and the i5 is ULV (ultra low voltage) CPU. The i5 in this case is more power efficient.
The S400 with i5 spec also has a mSATA SSD for caching, which make boot up / regularly used apps launch slightly snappier.
For MS Office 2010 (Words, Excel, Powerpoint), you will not notice much difference in raw processing power. The i5 spec one, due to the mSATA SSD caching, however, may seems to be more "responsive" in certain circumstance.
Thank you for the detailed explanation, appreciate it.
I think if I want to ensure really fast performance, maybe I should install microsoft office 2007. Sure fast one, right? But the problem is I asked around and it seems that office 2007 are not selling anymore.