be routed directly from a QSFP to CX4 cable

 Due to the physical specification for CX4 based 10 Gigabit, it provides a lower latency than comparable 10GBase-T copper PHY solutions. With the use of CX4 passive (copper) cables, the nominal distance you can expect between your 10GbE links is ~10-15m.   There are also amplified 'active' (but still copper) cables with nominal distances up near 30m.QSFP to CX4 cable are available broadly in the market today and SFP+ type designs for both optical modules as well as Direct Attach connections have been demonstrated and will be getting rolled out very soon by various vendors It provides a highly cost-effective way to establish a 40-Gigabit link between QSFP+ ports of QSFP+ switches within racks and across adjacent racks. FIberStore provide QSFP+ cables including QSFP+ to 4 SFP+ Breakout Cable, QSFP to CX4 Cable, QSFP to XFP Cable. These cables are available in lengths up to 20m, and we also offer custom cable length to meet your requirement high bandwidth, reduced power cost needed for HPC super computers and large data centers.