Random drop is FPS, is it my specs?

Hey I'm not much of a computer person and I was curious about why I get these random FPS drops while in game and I could be doing nothing but sitting and chatting. If I need to upgrade something please let me know. ><

Operating System: Windows 7 Home Premium 64-bit (6.1, Build 7601) Service Pack 1 (7601.win7sp1_gdr.130708-1532)
Language: English (Regional Setting: English)
BIOS: BIOS Date: 06/11/10 09:58:21 Ver: 07.04
Processor: AMD Athlon(tm) II X4 630 Processor (4 CPUs), ~2.8GHz
Memory: 4096MB RAM
Available OS Memory: 4094MB RAM
Page File: 4040MB used, 4146MB available
DirectX Version: DirectX 11

Card name: AMD Radeon HD 7700 Series
Manufacturer: Advanced Micro Devices, Inc.
Chip type: AMD Radeon Graphics Processor (0x683F)
DAC type: Internal DAC(400MHz)
Display Memory: 4095 MB
Dedicated Memory: 3072 MB
Shared Memory: 1023 MB

When I did the benchmark for Desktop (high) which is my current settings in game, and maximum they both scored fairly high but my fsp likes to stay at 15-18 and then randomly drop to 7-8 fsp >< The two lower settings I can stay at 28-30 then it also drops to 11-12.