[mschuster91]

In practice though 10G via copper requires pretty perfect terminations. The slightest error leads to crosstalk issues.

[JonChesterfield]

Ymmv. I've got a mix of cheap premade patch cables and some I crimped from solid core, all cat5e, all holding 10gbe totally happily. I suspect that only works because they're a meter or two long but that reaches across the rack.

[userbinator]

NICs have DSPs to cancel out crosstalk.