Differences:Su-30MKI-
Maximum internal fuel - 9,640kgs
Max Range(without mid-air refueling) - 3000kms
Max ceiling - 17.3km
Max Speed - Mach 1.9
Canards - Yes
Crew - 2
Max Afterburner Thrust - 12500kgf, Emergency Thrust - 12800kgf
External Fuel Tanks - No
Composites - Not in significant quantity.
Empty Weight - unknown. Estimated to be around 18400kgs.
Airframe life - 3,000hrs or 15 years(at 200 hours flight time each year)
Internal Jammer - No
RCS - unofficial estimate 11.5m2
Airbrake - Yes
Supercruise- No
Su-35S-
Maximum internal fuel - 11,500kgs
Max Range(without mid-air refueling, without external fuel tanks) - 3600kms
Max ceiling - 18km
Max Speed - Mach 2.25
Canards - No (since radar isn't heavy)
Crew - 1
Max Afterburner Thrust - 14500kgf(gives a massive boost to TWR compared to Su-30MKI)
External Fuel Tanks - Yes (can carry 2 drop tanks of 1400kgs fuel in each of them)
Composites - Yes. Extensive use of Titanium Alloys.
Empty Weight - Unknown. Estimated to be around 18800kgs.
Airframe life - 6,000hrs or 30 years(at 200 hours flight time each year)
Internal Jammer - Yes
RCS - unofficial estimate between 1-3m2
Airbrake - No. Powerful modified rudders act as Airbrakes.
Supercruise - Yes
Radar-
This deserves a separate mention. Because this is where the difference is at its max.
Su-30MKI has a N-011M BARS Radar
Transmitter peak power - 5kw
Transmitter average power - 1.2kw
Can Track- 15 Targets
Can Simultaneously Engage - 4 Targets
Max Detection for 5 sqm RCS - 140 km(Upgraded Radar with upgraded transmitter power, if any in service, its range is unknown.)
Su-35S has N-035 IRBIS-E. The most powerful Fighter Plane mounted X Band radar in the world. Specs are as follows.
Transmitter peak power - 20kw
Transmitter average power - 5kw
Can Track - 30 Targets
Can Simultaneously Engage - 8 Targets
Max Detection for 5 sqm RCS - 426 km
Max Detection for 3 sqm RCS - 375 km
Max Detection for 1 sqm RCS - 285 km
Max Detection for 0.01 sqm RCS - 90 km
DATA FROM OFFICIAL SUKHOI and NIIP WEBSITES. Not Wikipedia!
Armed-
Su-35S1 × 30 mm GSh-30 cannon with 150 rounds
2 × wingtip pylons for air-to-air missile R-73 (AA-11 "Archer") or ECM equipment
12 × wing pylons and close to 8,000 kg (17,630 lb) of weapons, including:
Air-to-air missile
AA-12 Adder (R-77)
AA-11 Archer (R-73)
AA-10 Alamo (R-27)
And may be armed by china
PL-8/9/10/12
Air-to-ground missiles and sea
AS-17 Krypton (Kh-31)
AS-16 Kickback (Kh-15)
AS-10 Karen (Kh-25ML)
AS-14 Kedge (Kh-29)
AS-15 Kent (Kh-55)
AS-13 Kingbolt (Kh-59)
bomb
KAB-500L
KAB-1500 laser guided bombs / TV
FAB-100/250/500/750/1000
Su-30MKIfireworks
1 serving GSh-301 30 mm, 150 rounds
Air-to-air missiles:
6 × R-27R/AA-10A/Astra [21], medium-range missiles, radar-guided semi-automatic, range 80 km.
6 × R-27T (AA-10B), medium-range missiles probe pink ngoao, 70 km
2 × R-27P (AA-10C), long-range missiles, radar detectors, passive
10 × R-77 (AA-12), medium-range missiles active radar detector, 100 km
6 × R-73 (AA-11) short-range AAM, 30 km
Air-to-surface missiles:
2 × Kh-59ME, radio guided missile, 115 km
2 × Kh-59MK, laser guided missile, 130 km
4 × Kh-35 anti-ship missiles, 130 km
3 × PJ-10 Bramhos, supersonic cruise missiles, 300 km
6 × Kh-31P / A, anti-radar missiles, 70 km
6 × Kh-29T / L laser-guided missile, 30 km
4 × S-8 rockets (80 guided rockets not)
4 × S-13 rockets (20 guided rockets not)
Bom:
6 × KAB-500L laser-guided bombs
3 × KAB-1500L laser guided bombs
8 × FAB-500T
28 × OFAB-250-270
32 × OFAB-100-120
8 × RBK-500 cluster bombs
Both Su-35S and Su-30MKI aircraft are the super-maneuverability, with technological security RCS almost similar (Su-30MKI use the opto-electronic system of Europe, only to attack the land), I think we will have duel between Su-30MKI and the Su-35S (export version for China)