System Workbench for STM32

Hi guys,
I'm using the STLINK v2 debugger that comes with the nucleo boards to debug my project. I've upgraded the firmware to JLINK but I was wondering how I can increase the speed of the link. I can't get it to go above 1000kHz. I've also got a Nordic nRF51 debug board on which the JLINK debugger can connect to the Nordic MCU at 25MHz. But when I try to use it with my STM32 MCU, I'm still limited to 1000kHz even if I use JLINK tools like JLINK Commander and JLINK flash. Btw the MCU I'm working on is STM32F207.
Does anyone have any ideas? Thanks!