# build rate définition

I discovered that a T3 engineer use x mass per sec to build a building and it use y masse per sec to build a other building.

The build rate of the engineer is not constant. So why it is said that a T3 engineer has a build rate of 30 ?

What does it mean exactly ?

Thanks

having a build rate of 30, compared to a T1 engineer (build rate of 5) means that whatever the T3 engineer is making, it will use 6x as much mass + energy as a T1 engineer making the same thing.

(assuming that there's no mass stall and no power stall)

And the same thing applies to factories. A t1 fac has a build rate of 20, a t2 fac has a build rate of 40. So if they're making the same kind of unit, the T2 fac will try to use exactly twice as much mass+energy per second.

But the exact amount of mass and energy differs depending on what is being built. So in practice, t2 facs tend to use more like 2.25x as much mass/second as a T1 factory if you're making t2 tanks instead of t1 tanks.

Units and buildings have build costs (mass cost, energy cost, and build time cost). A t1 engineer has a build cost of 260. You can take 260/20 to get 13, meaning (if there is no stall) it takes a t1 land factory 13 seconds to build a t1 engineer.

For each of those 13 seconds, the factory is trying to spend 1/13th of the total mass cost of the engineer and 1/13th of the total e cost

If you have two t1 engineers assisting the factory (each adding 5 build power to the factory's 20), then it would be about 9 seconds to complete the unit (260/30 ~= 9).

Buildings are priced the same way, in that they have a mass cost, an e cost, and a "build time" cost. Like a t1 torpedo launcher has a build cost of 450, that means a t3 engineer would need 15 seconds to make it (450/30 = 15).

One reason for a difference in mass/second and e/second is because different units have different ratios of total mass cost vs total e cost. Tanks tend to have a much higher ratio (more mass less e) and planes tend to have a much lower ratio (less mass more e).

The amount of "build time" needed to make a building is adjusted as part of how the game is balanced. If you need more engineers to get something built, that's a debuff. So it's a way to make something more expensive without actually increasing the mass cost. Or a building can be "buffed" by reducing the build time. For example, a relatively recent balance change was to reduce the build time cost for making TMD so you can build them faster in an emergency if tactical missiles are coming at your base. If you're not in an emergency situation you might not notice the difference, the important thing will be the mass cost of the TMD. But if there is an emergency, you're mostly worried about the build time cost.

Build time also is an issue for buildings that make things over time, like a strategic missile launcher or a strategic missile defense. And this is also adjusted for balance. A SML has 1500 build rate which means it would take 300 t1 engineers assisting it to double how fast a missile comes out (or: 50 t3 engineers).

Hello thanks a lot for such a detailled answer. But I don't understand something.

Here you are saying that :

"Units and buildings have build costs (mass cost, energy cost, and build time cost). A t1 engineer has a build cost of 260.
You can take 260/20 to get 13, meaning (if there is no stall) it takes a t1 land factory 13 seconds to build a t1 engineer."

So factory with a build rate of 20 means it can use maxi 20 max per sec.

But at first you said that :
"But the exact amount of mass and energy differs depending on what is being built."

Meaning that the rate of 20 doesn't mean it can use 20 mass/sec.

What is correct then ?

20 buildpower means it spends 20 buildpower per second towards the buildtime cost of the unit. The amount of mass that takes per second depends on the ratio of mass cost to buildtime cost.

Outch I miss the point.

Here is an example (maybe my data are wrong)

An air scout cost :
40 mass
1600 élec
Time = 400 (= 400 sec ?)

So 0.1 mass taken per sec to build this.
And 4 elec per sec to build this.

Am I correct ?

If yes then where do I need to use the build rate of 20 of the air Factory?

T1 air Factory has a build rate of 20.

200 / 20 = 10

The cost to make a scout is 200 buildpower, not 400 bp. you can look it up in the unit database.
The t1 factory has 20 buildpower per second
So the total time to make a scout plane is 10 seconds

The math is:
200bp / ( 20 bp/s) = 10s

If you were using a T2 air fac to make T1 air scouts, it would only take 5 seconds
200 bp / ( 40 bp/s) = 5s

The mass vs. bp costs are: 40 mass and 200 bp. 200/40 = 5. This means for every 5bp you spend on air scouts, you need to spend 1 mass.

Since the factory has 20bp, it will spend 4 mass/second making scouts

You have discovered one of the deep inconsistencies of the SC build system - build power is NOT universal - and it's not relative between engineers and factories.

The mere idea that a small mobile construction unit could channel more mass and energy over a given time, than a purpose built construction facility of considerable size and cost is just - well - wrong. It's the underlying support for engineer spam and a number of other counter-intuitive game mechanics.

arma473 has it right. Another way to say it is that: ConsumedResourcesPerSecond = Total Cost / Build Time * Build Rate

Some examples of different Costs per Build Rate are:

T1 Mass extractor:
0.6 (36/60) mass
6.0 (360/60) energy

Monkeylord:
0.73 (20,000 / 27,500) mass
9.45 (260,000 / 27,500) energy

Perimeter Monitoring System:
4.0 (4,800 / 1,195) mass
50.2 (60,000 / 1,195) energy

T1 Mass Storage:
0.8 (200 / 250) mass
6 (1,500/ 250) energy

Strategic Missile:
0.027 (12,000 / 450,000) mass
3.1 (1,400,000 / 450,000) energy

This is how much a T1 engineer (5 Build Rate) would be consuming while it is building these various things (Format is M/E):
T1 Mass extractor - 3/30
Monkeylord - 3.65/47.25
Perimeter Monitoring System - 20/251
T1 Mass Storage - 4/30
Strategic Missile - 0.135/15.5

These are the corresponding build times for a single T1 Engineer. This is just Build Time / Build Rate:
T1 Mass extractor - 12 seconds
Monkeylord - 91 minutes
Perimeter Monitoring System - 239 seconds
T1 Mass Storage - 50 seconds
Strategic Defense Missile (can't be built JUST by a T1 engineer, but if it could....) - 25 hours

You should see that the Cost per Build Rate is totally independent of the Build Time. The Perimeter Monitoring System will use 20 mass / second from even a T1 engineer to build because for whatever reason the blueprint is very fast to build, while the Strategic Missile uses very few resources from any single assisting engineer because the Build Time is HUGE.

Hopefully this helps.

(Data is on https://unitdb.faforever.com/)

Ok thanks so I was wrong, third value to build a unit or a structure is not called time, it is built power. Right ?

Using build rate (or build power rate) I can find the time for construction and then I can make a division to find how many mass or energy it will cost per second.

Am I correct ?

buildpower = buildrate = how fast something builds something else

buildtime = build cost= time to build something

when people refer to things

@iostrym yep, and if you select a unit in-game that can build the thing you want to build, then the UI automatically calculates the time to build and the resource cost from that specific unit, or do the basic math to compare units that you know the build power of (A T1 engi builds at 1/6th the speed of a T3 engi, or 1/2 of an un-upgraded ACU, etc)