Ok, with the same questions about SetCPU popping up on a daily basis, I decided to make a guide on how to use it. Really it's pretty simple, but it seems like it is the number one problem affecting this section of the forum on a daily basis.
1. First off you MUST be rooted and have a ROM or at the very least an Overclocking Kernel installed or it won't work! If you need a suggestion, I would say that my guide is the easiest, most trouble free way of getting a ROM on your phone WHILE still educating yourself on the process. It comes with an overclocking kernel.
[How To] Easily install Bugless Beast using only SPRecovery, Terminal Emulator, & zip
2. Next, download SetCPU for $0.99 from the Market. The first time you run it, it should ask you if you want to "allow" or "deny". Obviously you are going to choose allow or the program, as you can imagine, wouldn't run without allowing permission.
3. When you boot up SetCPU it will ask you what device you are using.
DO NOT, I REPEAT, DO NOT, SET THE DEVICE TO THE MOTOROLA DROID!!!! Scroll down and select "autodetect". Alternatively if you already messed up (because you didn't search on the forums for what to do with SetCPU before you went ahead and installed it) hit Menu > Device Selection. Here is a screen shot:
4. Next, go into SetCPU and check the Set on Boot box, and set your sliders to what you want the phone to be standard We will discuss profiles later. Basically your standard, or normal setting that you see on the front screen of SetCPU is going to be what the phone defaults to when NONE of the Profiles (if you are using them) are considered "true". Here is a screen shot of what I have mine set at (I also keep my Governor at "ondemand" which according to the developer makes it faster but uses more battery...the developer says to set it to "conservative" for slightly slower response time but better battery usage):
5. If you want to set up profiles, click the Profiles button, and then check the "Use Profiles" box. Here is a screen shot of how I have each of mine set up. Notice each profile box must be checked to enable it. Each of the profiles trumps the standard setting. So when my phone is charging, it DOESN'T use the standard setting that you see in step 4, it uses the profile for charging instead. I have the following profiles:
Standard: 550/1000 (I want the phone to have the most juice I can without overtaxing it, so I don't want it to go back down to 250 at any point)
Charging: 250/550 (This will allow the phone to stay cooler while charging as well as charge faster)
Sleep: 250/550 (When the phone is locked, I want it to have enough power to not lag when coming out of lock but still not use too much juice so I have it set to the stock setting...this is what helps you save battery)
When Power is Less Than: <21%...so any time my phone starts running low on battery it goes back to the stock 250/550
Battery Failsafe: >37C 250/550 ... you can see why I chose this setting for this, here:
Tell me your thoughts on this SetCPU idea...
6. Troubleshooting....if you have followed every last instruction to the T and still can't get your slider to the overclock position that you want, try rebooting your phone, hitting refresh, or or unchecking and rechecking boxes. You really shouldn't still have a problem after all of this, however.
7. Benchmark. To benchmark your system hit the System Info button on the main screen and then the Benchmark button. Usually you need to hit it 5-10 times in slow succession to get a good idea of your average benchmark.
8. If you are concerned about SetCPU, overclocking, and how it will affect your system temps, please go to this thread:
[Official] CPU Temp Results