Hardware for minimal latency

Hi there,

I just bought and tested a Steinberg UR12 and it’s definitely a huge improvement over my old soundcard. Now I’m able to play with 64 Samples with real low latency using the Yamaha Asio driver, which is much more fun! However, with 64 samples I get some crackling here and there (like I got with my old soundcard for 256 samples, 64 samples were impossible with crackling-only). This happens while my CPU is NOT occupied. But when it’s not the CPU, what is it then? Is a even better sound interface the only option?

Here’s my PC setup:

ASUS H87-PRO (C2) Intel Xeon E3-1230v3 Bx, LGA1150 Gigabyte GeForce GTX 770 Windforce 3X OC, 2GB DDR5, 2x DVI, HDMI, DisplayPort 16GB-Kit Crucial Ballistix Tactical Series DDR3-1600, CL8 Seagate Desktop SSHD 2TB SATA 6Gb/s NCQ 8,9cm (3,5") SSHD

Thanks for your help!