Does the MBP support Intel's SpeedStep?

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Does the MBP support Intel's SpeedStep?

Just wondering if the MacBook Pro is making use of Intel's Enhanced SpeedStep Technology? I was looking at the sysctl -a output and saw this:

hw.cpufrequency: 2000000000
hw.cpufrequency_min: 2000000000
hw.cpufrequency_max: 2000000000

To me, that implies that Apple isn't enabling the clock / vcore reduction to save power & heat.

MacBook Pro 15" 2.0GHz, 2GB, 100GB 7200, Mac OS X (10.4.5)

Posted on Mar 5, 2006 5:39 PM

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Answer 1

Mar 5, 2006 6:42 PM in response to Transeau

that's very interesting.

This is a question that needs answereing like pronto.

Apple (or a third party for that matter) should easily wip up a widget for speedstep.

We pay all this dough-geesh! you would think.

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Answer 2

Kappy

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361,741 points

Mar 5, 2006 6:49 PM in response to Transeau

Maybe this is the reason:

System Requirements for Intel SpeedStep Technology

Mobile Intel® Pentium® III processor with Intel SpeedStep technology
A chipset, BIOS, voltage regulator and operating system that supports Intel SpeedStep technology
Intel SpeedStep technology driver

Since Apple is using the Core Duo chip, not the Pentium III, SpeedStep would not work.

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Answer 3

Mar 5, 2006 6:53 PM in response to Kappy

No, I think speedstep does work on all Intel mobile chips.

I'm pretty sure.

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Answer 4

Kappy

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Mar 5, 2006 7:10 PM in response to mac wison

You're right. Further research at Intel indicates that Core Duo chips have Enhanced SpeedStep technology.

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Answer 5

Transeau Author

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31 points

Mar 5, 2006 7:11 PM in response to Kappy

Very outdated info you found there.

"Intel Enhanced SpeedStep Technology" is available on most of Intel current CPU offerings. The Intel Pentium 4 630 has it, as well as every Intel Pentium M CPU (The Core Duo and Core Solo are in fact Pentium M processors)

So - the bottom line is if Apple is making use of this feature. While booting in Single User mode, you can see that the CPU has the EIST flag, so I know the CPU supports it, but there is nothing to indicate if it's enabled or not.

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Answer 6

Transeau Author

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31 points

Mar 5, 2006 7:21 PM in response to Transeau

In the PC world there is an application call cpuz that can show you exactly what the current core MHz and voltage is. Some info from Intel's site:

• Multiple performance modes, ranging from the lowest to the highest frequency mode, to enable optimum
performance at the lowest power
• Real-time dynamic switching of the voltage and frequency between multiple performance modes, based on
CPU demand. This occurs by switching the bus ratios, core operating voltage, and core processor speeds
without resetting the PC.
• Software control of voltage and frequency operating points

I assume the Core Duo works much like the rest of the Pentium 4 family and is "SpeedStepped" via the multiplier. That would make the Max Multiplier 12x and the Min should be 5x ~ 8x.

I'm interested to see if and how OS X is dealing with it.

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Answer 7

Mar 5, 2006 7:22 PM in response to Transeau

Wouldn't the MacBook be dying a thousand deaths on battery life it it weren't supporting SpeedStep? Or is the Core Duo that good that Apple can get away with an incredible bug like this and still have battery life that vaguely resembles the PowerBook?

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Answer 8

Mar 5, 2006 7:39 PM in response to Transeau

I imagine speedstep is active and working fine but the problem is that it's not exactly 100% trouble free.

It works great but it can get stuck at one speed so i'ts very important to be able to see what freq. the cpu is at so if it does get stuck at 2GHZ, you can reboot (so you don't overheat)

It's certain apps I think that cause the speedstep to wig out. But if this is the case, and that rare app happens to be your favorite, you've got a problem.

so you need to monitor it. Of course very few people do on Windows machines, but they are average users so to ** with them, right? : ) (just kidding)

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Answer 9

Transeau Author

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31 points

Mar 5, 2006 7:29 PM in response to decisivemoment

Good question - The Core Duo is one of the most efficent CPU's that Intel has. It's 65nm, and supports the C1E (Enhanced Sleep State). That basicly turns the cores off when they are idle. I'm 100% sure that the C1E sleep state is enabled. This would allow for 2+ hours of battery life. But then you are browsing the web, there is no need for 2 cores running at 2ghz - they should be able to drop to a single core, at about 600mhz or maybe 1ghz.

I'm just curious if they are going all the way, or if that is in the future of the MBP.

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Answer 10

Kappy

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Mar 5, 2006 7:33 PM in response to Transeau

You can use the Processor preference to turn one of the cores off.

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Answer 11

Transeau Author

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Mar 5, 2006 7:36 PM in response to Kappy

Yes, I know that. and I normally keep only one core enabled unless I'm compiling code or editing video.

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Answer 12

Mar 5, 2006 7:42 PM in response to Transeau

I question that . Seems to me that you should not do that.

Just MHO

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Answer 13

Mar 5, 2006 7:44 PM in response to mac wison

Hey I was just thinking... wouldn't it be funny if SpeedStep were running under Rosetta!?! That's probably what's making the CPU whine all of the time!

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Answer 14

Kappy

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361,741 points

Mar 6, 2006 6:25 PM in response to Transeau

Pardon the delay, but I stumble upon this quite by accident. I was trying to learn more about the Sudden Motion Sensor and Safe Sleep, so I was researching info on the power manager command, pmset. See the following:

http://developer.apple.com/documentation/Darwin/Reference/ManPages/man1/pmset.1. html

The above is the man page. You'll note in the section Arguments an entry "dps". I think this may be the "speedstep" control.

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Answer 15

Transeau Author

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31 points

Mar 6, 2006 7:59 PM in response to Kappy

I did see both the "dps" and the "reduce", however the pmset -g does not show the current status like it did on the PowerBook G4

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