The numbers below should be the best middle ground for most ITX boards but the most optimal length depends on you specific motherboard. For standard SFX PSUs, add 30 mm to these lengths.
- ATX 24pin cable - 270 mm
- EPS 8pin/2x4pin cable - 400 mm
- GPU 6+2pin cable - 230 mm
- SATA SSD power cable - 130 mm
- SATA HDD power cable - 275 mm