SpeedStep (EIST = Enhanced Intel SpeedStep Technology) is a function of Intel's current Mobile and 6xx/8xx/9xx processors. It dynamicly changes the clock multiplier and the core voltage to reduce power draw while the CPU(s) are idle.
For example - The Pentium M 1.8GHz CPU run at 1.8GHz and 1.3v at full speed. When it's idle or under light load it runs at 800MHz and .96v. EIST also includes the "C1E" Idle state. C1E is a sleep state that turns off one or both CPU cores when the system is completly idle. It allows a notebook to run for up to 4 hours (8.5 hours with dual batteries).
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There is no reduce or dps. So, in fact the MBP does NOT support any form of frequency scaling.
sigh just one more nail in my MBP's coffin. (Closer and closer to eBay it goes)
Given that only certain Powerbook models actually had an ability to switch the processor speed during idle/sleep, I don't understand why this would be the deal-breaker for you.
But to each his/her own. I'm quite happy with mine.
I think we could at least draw some inference about this from the Powerbook DL SuperDrive, which uses a variation on SpeedStep to either divide-by-two the processor speed (a feature that goes back a couple of years) or divide-by-four the processor speed (new on the Powerbook DL, optional for the 7447 and required by the 7448, hence only the Powerbook DL can take DayStar's 7448 upgrade).
Bottom line is that Powerbook advertised maximum light use battery life (i.e. no Bluetooth, no Airport, no Photoshop, dim monitor, hard drive on most conservative energy setting) went up from 4.5 hours to 5.5 hours -- but heavy use battery life remained in the 2.5 to 3.0 hours range. Apple acknowledges this in their detailed technical overview document on the Powerbook DL
If it is possible for MacBook Pro users to get up from the 3.0 hour range that everyone seems to be in with all the toys running except the DVD, up towards five hours for light use, that would imply to me that SpeedStep is operational. Remember that SpeedStep does not power down the computer as far as PPC's divide-by-four, but that it is more fine tuned and works in 200MHz increments. A previous poster noted 800MHz as the minimum for the Pentium-M and I seem to recall 1GHz for the Core Duo. Also remember that we already know from Anandtech and other geek sites that the range of battery life on a CoreDuo system seems to be less between light and heavy use than on a Pentium-M.
This is an OS issue since it clearly works excellent in Win XP on the Macbook Pro. Just check the "Properties" on "My Computer", the CPU frequency is lowered when idle.
Interesting. Does the MacBook[with latest speedstep updates] run cooler in WinXP? I have not installed bootcamp yet(still no XP license). Did anyone test this, are the fans more active?
I use bootcamp and have a program on windows that can measure CPU frequency. It shows speedstep is working and the CPU is throttling down to 1ghz. As I do not know of such a program for OSX I can not see what OSX is doing. However, the fans come on more easily in windows and the battery life is a lot poorer, 2 hours at best. I'd say that OSX is using more power saving features than windows is so it must be doing CPU frequency throttling.
I'd read that Core Duo has many more power saving features, disabling second core when not needed, turning off large parts of the cache, CPU throttling handled by the CPU rather than software. If OSX is using these features of it, it might not necessarily show up in the same way as power saving features of the G4.
