GTX 670 extreme lag when bruteforcing wpa

[qtotheball]

When bruteforcing a WPA handshake using cudaHashcat-plus64 my computer lags extremely bad. Bad enough that just moving a window a short distance causes the computer to freeze for a second or two. My previous computer had dual 9800 GTX geforce cards in it, ran a much slower processor, but didn't experience anything close to that amount of lag when bruteforcing wpa with hashcat. This makes me wonder if I am doing something incorrectly, or if maybe my previous computer ran better because of the dual cards possibly? Any advice would be greatly appreciated =) Thank you for your time.


Running Win 7 Ultimate
ASUS Rampage IV Extreme X79
Intel Core I7 3930K
Geforce GTX 670
16 GB Ram