An overclocker upgrade can be used to speed up machines at the cost of higher energy consumption. Place one or more overclocker upgrades into the four right-most slots to upgrade a machine.
Each upgrade reduces the operating time to 70% of the previous value and increases energy consumption by 60%. The overclocker upgrade's effects stack exponentially. For example, two upgrades makes the machine operate at (0.7)^2 = 0.49 times normal time (100% faster) and use 1.6^2 = 2.56 times the energy (139% more). 8 of them will run the machine at over 8 times normal speed, and use over 43 times as much EU.
Overclocker upgrades result in poorer energy efficiency (more EU will be consumed per operation). This results in a 12 percent increase in energy per operation per upgrade (0.7*1.6 = 1.12, (1.12)^10 = 3.11 ). While building multiple machines makes better use of a limited energy supply, but overclocking allows for reduced space and wiring requirements when time or compact construction are more important or energy is plentiful. The reduced efficiency can be mitigated by combining both approaches, dividing a number of overclocker upgrades evenly between a handful of machines.
An overclocked machine's speed cannot exceed 1 operation per tick, so adding additional overclocker upgrades beyond that point is useless.
See: Crafting Guide
This section is intended to provide some explanation and practical examples for using overclocker upgrades.
This revision includes the revised power consumption for 1.71.
Each IndustrialCraft2 machine has a rated current draw (required EU/tick), a time to process the materials and internal EU storage. When calculating the effects of overclocking, we need to include these factors. The differences on each machine mean that some machines need more or less overclocker upgrades to reach peak speed.
The main limit to the number of overclockers you can use is the power requirement. To make machines run really fast, you need to feed them with multiple power supplies, big ones.
Also, you can't get it to process any faster than 1 operation per tick. Since there are only 20 ticks in a real-world second, you can never make an IC2 standard machine process more than 20 items per second.
Max speed benefits are obtained with: 16 overclocker upgrades for Macerators and Extractors, 13 for Electro Furnaces and 10 for Recyclers;. In each case you're going to need to put in transformer upgrades, use Glass Fibre Cable and storage upgrades.
A standard Macerator draws 2 EU/t, takes 20 seconds per grind and stores 625 EU.
Five overclocker upgrades are a great start. With 5 overclocker upgrades, your Macerator draws 21 EU/t (which can be supplied by a single BatBox) and completes each grind in 3.5 seconds instead of 20!
With 8 overclocker upgrades, your Macerator draws 85.9 EU/t and completes each grind in almost a second. You can still run this with tin cable but you'll need three BatBoxes in parallel to supply the power. Alternatively, you can put in one Transformer upgrade (which allows 128 EU/t) and use a CESU to power. Use Copper Cable or better!
As you put in more overclocker upgrades, the power requirements keep going up. 11 overclocker upgrades want 352 EU/s which would require 11 BatBoxes or 3 CESUs to drive. My suggestion is you put 3 Transformer upgrades in each machine early and then you can just upgrade to MFEs and MFSUs any time you're ready.
There is a break-point when you reach 13 OC's on the Macerator, 10 on the Furnace and Extractor and 9 on the Recycler. The energy required per tick exceeds the machine's internal storage. As you approach this limit, you may see the machine flicker or stutter as if your batbox was running empty. If you put in one more overclocker, the machine will stop entirely. Now you need to add one or more Energy storage upgrades before the machine will continue to function.
Maximum speed benefits can be achieved with 16 overclocker upgrades in Macerators and Extractors, 13 in Electro Furnaces and 10 in Recyclers. In each case you're going to need to put in transformer upgrades, storage upgrades and use Glass Fibre Cable. The Macerator is the greediest and will need 8 MFS Units to supply the necessary power.