Yes, the faster card will be clocked down some what to match the slower card. Try to overclock the slower card to more closely match the faster one.
Only issue I see is GPU-Z says your second PCI-E slot is running at 4x speed instead of 8x or 16x. This will bottleneck your crossfire a bit. Which motherboard do you have? The i5-2500K is a strong CPU and you should overclock it a bit, be sure yo get a decent aftermarket cooler though. You may want to look into a motherboard that supports two PCI-E lanes at 16x/16x or 8x/8x as the 4x speed will slow you down a bit.