Top speed of SU-35 is mach 2.35, about 1550kts. In BMS in clean, straight and level flight with full afterburner it won’t go much above 650kts. Tried different altitudes, diving to break through supersonic barrier, greater than 50% documented top speed is not possible. The same lack of top speed appears on several other aircraft.
Edit - Apologies, I was wrong about this, it must have been in IAS/CAS. Just test flown up to 37k, where it maxed out at about 465kts TAS. Then hit afterburners (clean - no stores/pylons). After breaking through the barrier at about 650kts it accelerated quickly to a top speed of 1453kts at 37k feet TAS. Thanks!