Tried programming STM32F1x using STM32_Program_CLI with both STLink/V2 & ST Link/V3 in SWD mode. Programming time for 640KB look same 30sec for V2 & V3 diff under 0.5sec -Why timings same? UM0892 doc says max SWD freq. for V2 is 4Mhz & for V3 is 24Mhz.
Programming times are mostly erase and programming times. SWD frequency is mostly so high that there is no noticable influence. B.t.w, what is the size of your binary?