First, Cat5e is a UTP (Unshielded Twisted Pair) spec, not an FTP (foiled) or STP (shielded) spec
Gigabit Ethernet, IEEE 802.3 1000BASE-T, supports 1,000,000,000 bits per second signaling over Cat5 and better (5e, 6, etc. ) UTP cabling. After overhead, good software can get 941Mbps of TCP throughput out of that.
Sometimes cables talk about what frequencies they're rated for, like "200MHz". That rating is meaningless as long as it truly meets or exceeds the Cat5 specification.
It may be worth noting that network speeds are traditionally measured in 1,000's of bits per second (kilobits, megabits, gigabits), whereas disk and file I/O speeds are traditionally measured in 1,024's of 8-bit Bytes per second (KibiBytes, MebiBytes, GibiBytes). So 941Mb/s is roughly 112 MiB/s.