Yes this is normal and nothing to worry about. By the way depending on how your Aspire's ram is configured 8gb of ram will make a dramatic improvement in performance and is cheap these days.
This is an even faster solution which may or may not be seen @ 1600 natively but the additional cost is worth the chance and if it doesn't 8gb @ 1333 is still wicked improvement. I wish this had been out when I up'd my lappy to 8gb's!
Corsair CMSX8GX3M2A1600C9 Vengeance Laptop Memory Kit - 8GB (2x 4GB), PC3-12800, DDR3-1600MHz, 204-pin SODIMM, 1.5V, CL9, XMP Ready at TigerDirect