This geth weapon works on the same principles as the Spitfire: it shoots superconducting toroids that break apart on impact, retaining an electrical charge that flash-converts the shrapnel into plasma. Unlike the Spitfire, however, the plasma SMG has been modified to take thermal clips. Holding down the trigger speeds up its rate of fire, rapidly depleting the gun’s heat sink in exchange for nearly continuous fire.
The Geth Plasma SMG "spins up" to a dizzying rate of fire (720 RPM at full ROF) and burns through the hundred round magazine in seconds. Using the SMG Magazine and SMG Heat Sink upgrades greatly extends the effective time in sustained fire after the rate-of-fire speed bonus has triggered.
Using the Geth Plasma SMG with power-based characters that relies heavily on quickly-recharging powers is not advised. The two seconds the gun takes to spin up to its full potential can leave you vulnerable to attacks, and every use of a power will force it to spin back up again.
The most obvious problem with this tactic is that prolonged fire, while out of cover, is likely to get users killed on Gold, recoil is increased slightly, and ammo consumed quickly.
The gun's high rate of fire and large clip pairs well with Cryo or Incendiary ammo (especially the level II or III versions). A sweep of gunfire over a group of weaker enemies can inflict widespread freezing or burning among them, slowing them down enough for squad members to deal with them.
When a geth multiplayer character uses this weapon, it inflicts more damage (only if points have been invested in the Networked AI passive power).
The Geth Plasma SMG has relatively low recoil and very high accuracy for its high rate of fire. (More accurate than most SMGs and assault rifles). Sustained fire can stagger foes, and achieving headshots during sustained fire is rather easy, allowing users to take advantage of the high rate of fire coupled with a headshot damage multiplier.
The Marksman power is extremely powerful on this weapon. With rate of fire upgrades, the Geth SMG spits death out in all directions. The extra headshot damage ability quickly eliminates most enemies even on the hardest difficulties in moments.
The Geth Plasma SMG is moderately effective against armored targets. Although the armor reduction reduces each bullet's damage to the minimum value (-50 DR on Gold), the weapons extreme rapid fire damage quickly adds up.
Its only real problem is its lack of damage which can be countered marginally with the SMG High Caliber Barrel upgrade.