I'm looking for suggestions on how other GM's handle combat situations, especially on a large scale when there are more then 20+ combatants. My next game there is going to be the potential for a very large firefight. I usually pre-roll initiative for my NPC's. I always bring my laptop to gaming sessions (For Sound Effects, some Videos, ect.) and I was thinking about using the Dice Roller program, especially for NPC's with large dice pools. Are there any other programs someone can recommend or different ways to run your SR combat? I appreciate any feedback. Thanks.

Use the Dice for Hits rules to simplify things among NPCs. If you have some grunts or whatever fighting it out and not directly involved in the fight with the PCs, just figure out what happens by buying hits. Example: Grunt A has a pistols plus agility pool of 8 and is shooting grunt B who has reaction 4. A buys 2 hits versus B's 1 hit. No dice roll needed. You can do the same for the damage resistance test. B has body 3 and Ballistic armor 5 so can buy 2 hits. This makes it easy to figure out who wins when it isn't PCs doing the fighting. I used this very mechanic in Ghost Cartels in Kowloon City (those who have played this should know which bit I'm talking about).
If one of these grunts moves on to fighting a PC directly just go to normal rolls. You only really need to roll the dice for things directly involving the PCs, so you could also just hand wave any NPC on NPC fights.

Buy Hits, single damage tracks for NPCs. Handwave and do the box test for non PC focused action, focus on the players actions.

The easiest is to do enough damage to the PCs they don't need to roll dice after the first attack....

I use Mass Combat rules from the Exalted game by White Wolf as the game rules for SR and Exalted seem to be easily interchangeable.

Roll Initiative only Once per fight ,not any Round

Hough !
Medicineman

I am yet to find such a high number of oponents on my games, but i am looking forward to it. So:

1) only one roll of initiative per battle
2) single damage track for grunts.
3) buying hits, even against the pcs.

The 3 item very important, because, in a firefight against a large number of oponnents, each foe reduces the target's reflexes per single action. That will make your players go for cover VERY quickly.

Ditto on this.

I would also suggest grouping bad guys into teams of 4 or 5 with one designated leader and have each extra guy add an extra die to the roll of the group leader to cut down on goon dice rolling. Perhaps even treating it as supresson fire.

If they are just goons I'd probably ditch the damage track all together and just say each goon can take 1 or 2 hits before they are out of the fight (either dead, nursing wounds, or running way, etc.).

The one thing that really helped us was when I (being the one player who is familiar enough with rules not to have to look up things too much) started tracking the initiative (including the passes) for both PCs and NPCs.

It frees the hands of the GM to concentrate on what the NPCs are doing, and saves the "what pass it is now?" and "I think I got skipped" debates between players that used to be a big hindrance...

depending on the professionalism of the opposition, start making them flee once they reach - say - 6 boxes of damage.

Try not to make the fight too easy - aka that mage with that stunball - spread the opposition.

You as the Player kept track of PC and NPC initiative? could you explain how that worked?

Easily - we do't roll for initiative every combat round (that speeds up things a lot too), so at the beginning of the combat I note down the initiative and number of passes of each PC, and then just start at counting down from 25, allowing the GM to add the NPC as their actions become obvious. I note where the NPC stands, and once again ask at the beginning of next pass, if the NPC acts or not. By the end of the first combat round, we all know anyway if that troll is a sammy with rtg3 reflex wires, or a norm with just one ini pass

And since I love tables, I created one that looks like this: http://img180.imageshack.us/img180/6941/tablel.jpg (a pic is always better then a lenghty description) - after the NPC/PC declares their action for the pass, I make a little cross in the respective column, so that nobody gets skipped. If anybody moves down in initiative count, I rewrite it.

The combat now really takes only half the time it used to...