I have a 650 ti and an x4 760k processor and i lag recording minecraft?

I record with Dxtory with lagarith lossless codec and 720p and I lag i get like 20-34 fps but i don't get it because when I'm not recording i get about 180-300 fps please help! Here are my specs

4GB of ram
650 TI GPU
X4 760K Processor
170 mb/s ssd hard drive

Try obs

Use Open Broadcaster Software with game capture source.

Try another recording program such as Bandicam (you can try it for free) to see if it also lags there. Then you'll know if the problem is DXTory or not. There could be a bottleneck somewhere such as your HDD write speed.