7850 crossfire的可行性求問~~

Operating System
Windows 7 旗艦版 64-bit SP1
CPU
Intel Core i7 3770 @ 3.40GHz 52 °C
Ivy Bridge 22nm Technology
RAM
32.0GB Dual-Channel DDR3 @ 798MHz (11-11-11-28)
Motherboard
ASRock H77 Pro4/MVP (CPUSocket) 39 °C
Graphics
VX2240w-2 (1680x1050@60Hz)
Intel HD Graphics 4000 (ASRock)
2048MB ATI ASUS HD7850 Series (ASUStek Computer Inc) 38 °C
Storage
465GB Western Digital WDC WD5000AAKS-22YGA0 ATA Device (SATA) 39 °C
596GB Western Digital WDC WD6401AALS-00L3B2 ATA Device (SATA) 40 °C
931GB Seagate ST31000528AS ATA Device (SATA) 35 °C
465GB Seagate ST3500418AS ATA Device (SATA) 36 °C
119GB ADATA SX900 ATA Device (SSD) 35 °C
2794GB Seagate Expansion Desk USB Device (USB (SATA)) 50 °C
3GB ADATA USB Flash Drive USB Device (USB)
Optical Drives
HWNGBMZ LYF8HA7GHU SCSI CdRom Device
PLEXTOR DVDR PX-L890SA ATA Device
Audio
AMD High Definition Audio Device


機子買一段時間了，時至今日再裝一張是否在性能上有顯著提昇？原來卡片買了6990~~近日發現同款卡片跳水4500左右，有時間幫評估的大大給個建議一下@@

感謝