Armor

T-90A has a better hull armor overall than the M1A2 Abrams. The M1A2 Abrams UFP armor is ~780 mm vs APFSDS, 600-700mm vs HEAT, but the T-90A armor is steel-composite-reactive blend (vs APFSDS: 700–800mm; vs HEAT: 900-1,600mm.) However, much of tank warfare is conducted in hull-down position, where only the turret is exposed. In this respect the Abrams is superior. The Abrams' turret cheeks are completely impenetrable to the T-90's rounds, while the M1A2 can easily penetrate the mantlet of the T-90 at most ranges, usually killing at least one crew member and disabling the breech. On another note, the T-90 has a tightly packed crew and autoloader that means most penetrations result in a knock out, while the M1A2's spaced out interior means it can survive even a few successful hits.

Engine

`The M1A2 Abrams uses an Honeywell AGT1500C multi fuel turbine engine with 1500 hp. The V-92S2 of the T-90A engines made by Uralvagonzavod is much weaker, about 1000 hp.

Range and speed

The T-90A is one of the main battle tanks with the longest operational range, about 650–700 km, much more than the M1A2 Abrams which is only 426 km. The T-90A's speed is also a little bit better than M1A2 Abrams. The M1A2 Abrams's on road speed is 56 km/h, off road - 40 km/h, while the T-90A's on road speed is 65 km/h and off road speed is 45 km/h.
Armament

The main armament of the M1A2 is the M256A1 120 mm smoothbore gun, designed by Rheinmetall AG of German with 42 rounds. The M256A1's rate of fire depends on the loader, and can surpass the T-90 because of this. The M256A1's effective range is 4000m. The M256A1 has a much better APFSDS round than the T-90 and also is able to make use of a saboted HEAT-VT shell for use against helicopters and other low-flying targets. The secondary armament is one 12.7mm M2HB heavy machine gun and two 7.62mm M240s.

The main armament of the T-90A is the 2A46 125 mm smoothbore gun with 43 rounds, which effective range is 5000m. The 2A46 is an autoloaded gun, so it can shoot at a fixed rate of 8 rounds/minute which can be an advantage for the T-90A. The 2A46 features an inferior APFSDS round to the Abrams but also has access to a specialized tandem gun-launched ATGM. The secondary armament is one 12.7mm NSV heavy machine gun and one 7.62mm PKT.
Final Conclusion

The T-90A overpowers the M1A2 Abrams in speed, and range, but the M1A2 Abrams has a better engine. The armament can be somewhat of a draw, because the T-90A main gun is autoloaded and has and has an ATGM, but the the M1A2 Abrams can fire better APFSDS and can be loaded faster. The armor is also somewhat on par, as the T-90 is superior in close quarters but the Abrams trumps at range while hull-down.