Due to the large amount of confusion surrounding Power Efficiency, this page has been created to elaborate on the maths used, and to discuss its validity.
Please use the Talk:Power Efficiency page or the comments to discuss or question anything on this page.
There are currently 3 items in game that affect Power Efficiency; Streamline, Essence Loki Helmet, and the Scorpion Ash Helmet
Power Efficiency formula:
Cost = (Base Energy Cost divided by (1 + X), where X is the percent power efficiency, and the result is rounded up.
Stacking formula: Cost = Base Energy Cost divided by [1 + (X+Y)], where X and Y are the power efficiency ratings of the objects being "stacked".
Verbal Description of Power Efficiency: Power Efficiency is not a reduction in the energy cost needed to activate an ability, but is instead an increase in energy value. It essentially makes 1 point of energy worth 1.X, where X is the percent power efficiency expressed as a decimal.
Notes: Although your energy is displayed in whole numbers, it is not calculated as such. Because of this, using abilities in succession will sometimes result in Power Efficiency causing an ability to cost 1 energy less than its reduced cost would otherwise have been. This is because rounding is only done on your displayed energy, and not on the actual amount of energy remaining.
Because of the rounding, all "cost tables" are figured when starting with max energy (Or the energy given when starting a mission). This way, we can guarantee that there are no decimals other than those that are created when using the first ability.
All numbers are figured without having Energy Siphon equipped because the constant gain of energy would throw off calculations.
Streamline General cost table with Streamline at 30%
| Base Cost | Estimated Cost | Cost Progression |
|---|---|---|
| 10 | ≈7.69 | 8 |
| 25 | ≈19.23 | 20 |
| 35 | ≈26.92 | 27 |
| 50 | ≈38.49 | 39 |
| 75 | ≈57.69 | 58 |
| 100 | ≈76.92 | 77 |
Essence Loki Helmet (Essence) Provides a 15% bonus.
| Base Cost | Estimated Cost | Cost Progression |
|---|---|---|
| 25 | ≈21.74 | 22, 22, 22, 21, 22, 22, 22, 21, 22, 22 |
| 50 | ≈43.48 | 44, 43, 44, 43, 44 |
| 100 | ≈86.96 | ? |
Proof of Essence's Power Efficiency Rating:
| Base Cost | In-Game Cost | x / (1 + 0.14) |
|---|---|---|
| 50 | 44 | 43.859649123 |
If it was 14%, the second activation of a 50 base cost ability would still show an In-Game cost of 44, but instead it shows 43.
Scorpion Ash Helmet (Scorpion) reduces Power Efficiency by 5%, resulting in a -0.05 being passed into the Power Efficiency formula.
| Base Cost | Estimated Cost | Cost Progression |
|---|---|---|
| 25 | ≈26.32 | 27, 26, 26, 27, 26, 26, 27, 26, 26 |
| 35 | ≈36.84 | 37, 37, 37, 37, 37, 37 |
| 100 | ≈105.26 | 106, 105 |
Streamline stacking with Essence. They stack according to the formula: Cost = Base Energy Cost divided by [1 + (X+Y)], where X is the percent power efficiency and Y is equal to Essence's 15% Power Efficiency.
| Base Cost | Estimated Cost | Cost Progression |
|---|---|---|
| 25 | ≈17.24 | 18 |
| 50 | ≈34.48 | 35 |
| 100 | ≈68.96 | 69 |
If we believe they are multiplicitive: (cost / (1.3)) / 1.15 = 33.738191633. Which rounds to 34, and is not the in-game value of 35. Thus they appear to be additive.
Streamline stacking with Scorpion It is currently unknown, how Scorpion stacks with Streamline mathematically. A more general formula is needed to calculate more accurate estimated costs:
Cost = (Base Energy Cost) / (1 + P) / (1 - N), where P is the stack of power reductions and N is the stack of power augmentation. In the case of a max Streamline, the new costs would be: (cost / 1.3) / 0.95.
| Base Cost | Estimated Cost | Cost Progression |
|---|---|---|
| 25 | ≈20.24 | 21, 20, 20, 20, 21, 20, 20, 20, 21, 20 20, 20 |
| 35 | ≈28.34 | 29, 28, 29, 28, 28, 29, 28, 28 |
| 100 | ≈80.97 | 81, 81, 81 |
| Damage |
| Critical Hit - Enemy Vulnerabilities - Melee Charge Formula - Multishot - Power Efficiency - Puncture |
| Elemental Damage |
| Armor Piercing - Electric - Freeze - Fire - Poison - Laser |