Diminishing Returns on Heat Dissipation

BIG WALL OF TEXT INCOMING, so skip to the tl;dr if you don't want to be bored by my methodology/ramblings.

So, thanks to the awesome work of u/SurprisedToasterOven and his weapon spreadsheet (found here), I had a good idea of nearly every facet of the weapons in this game except one: heat. Specifically, I wanted to get an idea for sustained DPS vs Burst DPS. In the end, I did manage to piece together a spreadsheet (found here), but my testing led me to a different discovery that kind of blew up some of my pre-conceived notions of how weapons and heat work:

TL;DR: Each additional fixed weapon you shoot imparts diminishing returns for sustained DPS per gun. This is because the amount of heat that your ship can sink per second appears to be fixed, but each additional gun generates more heat that needs to be sinked.

In other words, the time it takes to cool down four weapons is four times as long as the time it takes to cool down one single weapon. This is something that is fairly easy to test:

1. Load up an Eclipse with four Plasma (I chose plasma because they overheat fast, so less time shooting and more time measuring cooldown!). Put them into different groups, so one has one weapon, the next has two, etc.
2. Shoot each group until overheat, and then time how long it takes to cool down. From my testing, the cooldown times appear to be multiples of between 5.5-6.5 seconds, or so. In other words, one weapon takes ~6 seconds to cool down, two weapons take ~12 seconds, three weapons take ~18 seconds, four weapons take ~24, etc.. Now, I won't lie, this is not exactly precise. Depending on how good my reaction times were, there was a bit of variance in the time I recorded, but usually only about a second.

This is one of those little things that, upon testing, seems so obvious, but I never really noticed it. Like most people, I just rushed to the ship with the most hardpoints, and never realized that it took longer to cool down my weapons.

Now, at this point, you may be wondering "why should I care?". Well, the reason is because the increased dissipation time per additional weapon means that there exists a kind of diminishing returns for sustained DPS. Burst DPS before overheat stays the same. It will always be 8 rounds per Small Plasma Mk2 before overheat, for example. But the downtime after hitting the overheat threshold increases dramatically if you load up on a lot of guns.

This has much more of an impact on weapons that overheat quickly, because the dissipation rate seems to be fixed. From my testing, each weapon has a heat threshold of about 10,000 heat.** However, your ship only appears to be able to dissipate between 1550-1820 heat per second (10,000 heat divided by 5.5-6.5 seconds) regardless of how many weapons you have mounted. What this means is four weapons will have a combined heat threshold of 40,000 heat, but your ship can only sink around 1600 heat per second. As a result, the faster a weapon hits the overheat threshold, the less efficient it becomes when fired en masse, since you are spending more time bouncing between overheat and cool down, than firing freely. As an example, lets use Plasma again.

First, one weapon firing

• It takes 7 seconds for a Small Plasma Mk2 to hit the overheat cap. This is because it generates 1,409 heat per second. (1409 heat per shot, 1 shot per second, 1,409*7=9,863. Plasma even cheats a little because it can sneak in one more 1409 heat shot to go over the 10,000 heat cap for 11,272 total heat)
• Your ship can dissipate ~1700 heat, meaning it takes about 6.6 seconds to cool down (11,272/1700)
• For science, I fired continuously for 60 seconds and shot exactly 32 rounds, for 17,600 damage. This equates to roughly 293.33 DPS.

Now lets look at four weapons firing

• It still takes 7 seconds to hit the overheat cap.
• Now, however, your ship can still only sink about 1,700 heat, but you are generating four times as much heat. This means there is much more downtime between shooting.
• Once again, I fired continuously for 60 seconds and shot exactly 80 rounds (20 volleys of 4 plasma), for 44,000 damage. This equates to roughly 733.33 DPS.

So, four times the weapons, but only about 2.5 times the overall damage over 60 seconds. This mean each individual weapon is only 62.5% as effective! (733.33/4=183 33 DPS per gun vs 293.33 for a single gun). Finally, lets look at three weapons firing

• It still still takes 7 seconds to hit the overheat cap.
• Firing continuously for 60 seconds, I shot exactly 69 rounds (23 volleys of 3 plasma), for 37,950 damage. This equates to roughly 632.5 DPS.

The reason this is relevant, is because the fighters mounting three hardpoints are largely viewed as being pointless compared to the Eclipse, which mounts four. However, when shooting Plasma, due to diminishing returns, the DPS loss is not as great as one would think. Rather than doing 33.3% more DPS compared to, say, a Buzzard, it actually does ~16% more.

This is also important because it is yet another mechanic in this game that, to my knowledge, is not documented anywhere, but that affects the way the game works, in a subtle but still noticeable way. One reason Pulse Lasers are so good is because they take an eternity to hit the heat cap, and thus are less affected by the diminishing returns on heat dissipation.

Now, as a disclaimer, there is a LOT of napkin math here. Furthermore, my measurement of how long it takes to cool down after overheating is hardly the most precise. However, it was the best I could do, without knowing if or where the heat capacity and dissipation rates are listed. I certainly welcome anyone to double-check my findings and my math.

Finally, this is all assuming that you have the chance to just blaze away for extended periods of time, which is not necessarily possible, or even likely. Regardless of all these disclaimers, it is a thing that is measurable, so I hope you got something out of this.

Thanks for reading this wall of text!

**If you're interested, I fired a Medium Pulse Mk1 until it overheated, counted the number of salvos it took to overheat (147), multiplied that by the heat per bullet found in u/SurprisedToasterOven's spreadsheet (34), and multiplied that by the number of bullets per salvo (2). 147*34*2=9996. I did the same with each weapon and got similar numbers (eg. the bolt repeater was 11*21*43=9933 heat).