Both cards are SLI compatible, but my question is are they compatible with each other? They only difference that I can tell (in my untrained amateur PC builder mind) is that one is a 660 TI and other is just a 660.
Here is my current computer build.
-MSI 990FXA-GD65V2 AM3+ AMD 990FX SATA 6Gb/s USB 3.0 ATX AMD Motherboard
-AMD FX-6200 Zambezi 3.8GHz (4.1GHz Turbo) Socket AM3+ 125W Six-Core Desktop Processor FD6200FRGUBOX
-G.SKILL Ripjaws X Series 16GB (4 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model F3-12800CL9D-8GBXL
-XION AXP-700K14XE 700W ATX SLI Ready CrossFire Ready 80+ Bronze Modular Power Supply