C1/2/4E, what's the deal?

[Samury]

I understand the basic idea behind speed stepping, but I don't know what the different options offer. My MB (see sig) has all three of these, but the manual basically boils down to "allows this to work" which isn't really helpful. Searching this forum and with Google or Wiki has either sent me to threads saying, "Do a search, there's plenty of info out there" only there doesn't seem to be (see below), info on P4s, or info on companies with no relation to computers.

So I'd like a simple answer of what 1, 2, and 4 do to my CPU.

1 is pretty simple, as I can see that it lowered my original e8500 from 3160 to 2000, but what do 2 and 4 do? Is it a simple further reduction, a more efficient use of resources, a more efficient use of power with the same setting? Should I even care what these do?

Frankly, having searched Intel's site, I'm amazed how little info is readily, if at all, available about these settings.

 

[guspasho]

Simple answer, C2 and C4e are progressively more power-saving idle states. C1 and C2 are methods of shutting off the clock, C4e also reduces core voltage when the CPU is idle.

Check this page out. I'm guessing you didn't know the right words to search. I just searched "C-states" in Google.

http://www.hardwaresecrets.com/article/611

 

[Samury]

Yep, that is one term I didn't use to search. Thanks for the link.