Claim: X87 had more than ten implementations, one of which was the Cyrix 6x86 which had an FXCH of 2
Evidence: Cyrix 6x86, Cyrix MII 80486 (or 80487) 80387 (and later 287 models) 80287 (original) 8087 AMD K6 (including K6 II/III) Pentium / Pentium MMX Pentium Pro Pentium II / III Athlon (K7) Athlon 64 (K8) Pentium 4 2