MBA2012 cpu multiplier wrong and no turbo boost in Windows7

Instead of looking at what windows tells you or what that program tells you the processors are capable of, do some computing and see which one out performs the other. I've seen other sources that show that the i7 very well does out perform the i5 as it is expected to do.

http://www.macrumors.com/2012/06/12/benchmarks-for-mid-2012-macbook-pro-and-macb ook-air/

http://www.barefeats.com/mba12a.html

Also on my mid 2012 13 inch MBP I just had and returned I installed windows and the i7 in that,still a dual core, 2.9GHz turbo to 3.6 I believe, got a 6.9-7.2 rating on the CPU. It must be a bug causing the 3667u to show up with such a low rating.

This is not a reporting bug for sure. With CPU-Z. You can see the processor only going to 2.0 GHz under load, after the changes you could see it clearly hitting its proper turboboosting of 3.2 GHz. Heavy gaming before would not produce a lot of heat (sign of power usage) whereas after it was getting warm to the touch, not to mention a significant boost in actual FPS in games. Definitely not a reporting bug.

Okay using Throttlestop 5 (beta3) from Tech Inferno and setting the Multiplier to 32/Turbo I get these Windows Experience rating figures ("normal" figures in brackets:

CPU 7.1 (6.4)

RAM 7.5 (7.2)

Graphics 6.4 (5.9)

Gaming Graphics 6.5 (5.3)

Primary Disk 7.9 (7.9)

That's quite a difference! Was surprised to see even the RAM figure change a little.This doesn't sounds like just a "reporting" issue in CPUZ...

This is for a mid-2012 13" Macbook Air with a 2.0Ghz i7/8Gb RAM/256Gb SSD (Samsung)

Message was edited by: oxford_guy - added machine specs

+1. I'm quite worried here. Got a new MBA with i7, 8GB ram, 256GB SSD and concerned the cpu both isn't clocking lower than 1.9GHz or higher.

When is a fix expected? How do I apply the fix when it's released? Is there a link to an official bug report anywhere?

I'm only going to use this laptop for Windows so this is a big concern for me!

Jake

I spoke with Apple support today and the supervisor there is passing it on to an engineer to look into. I should hear back in around 4 days apparently. I also submitted this to Hacker News: http://news.ycombinator.com/item?id=4247360

Great, thanks Jake!

Hi Jake,

Any word back from Apple support on this? I'm guessing we'll have to wait for Mountain Lion, but it would be good to get some news on this issue.

Thanks,

John

I think there's going to be alot of p***ed-off i7 MacBook Air owners if a fix for this isn't released at the same time as the Mountain Lion launch

I have a response! After 5 days while their engineers looked into the problem after I'd linked them to this and other discussion threads and provided them with the information that originally requested I receied a really useful reply:

Our engineers are asking for some photos of the tools as screenshots to indicate the issues and also the version of windows you are using as a photo of the disc as from here we can see weather its Windows 7 Home Premium, is 64 bit or 32bit? or whatever the case may be.

My MacBook Air is now going back to the shop as it's still less than 14 days since I bought it. What a joke.

@Jake - that sounds like they're not even aware of the problem, which slightly beggars belief! Unless, that is, another part of Apple is looking into it and they're just not aware of this (I hope...).

I makes one wonder why I paid the premium for the i7 processor if the performance is (currently) worse under Windows than the i5 because of a fault Apple have made...

BTW I have the same issue and am running Windows Professional 7 64-bit

Wow, not at all promising. Unfortunately all the CPU intensive stuff I have to do has to be done under Windows. I'm seeing the same issue with Win 7 x64 Ultimate, but I'm fairly sure that the version of Windows has little to do with the problem. They should be able to see it on any i7 running Windows under Bootcamp.

Hope they start taking a deeper look at this soon.....

John

Dude, looks like you are one of the only people who know what's really wrong here.

I really hope Apple is taking a look at this and fixing the EFI. It's not a Windows problem, not a hardware problem. Just a firmware problem - Apple probably forgot to put in the correct parameters for the i7 CPU in the EFI.

I've just got a CTO i7 Macbook Air and use Bootcamp exclusively. It's quite disappointing and worrying that Apple has not officially acknowledged this problem. All I see are users mentioning that Apple engineers have acknowledged it, but no official word from them.

I think I found a way to script this, using a little utility called RW-Everything. Got the idea from here:

http://www.xtremesystems.org/forums/showthread.php?171105-Howto-disable-the-tlb- fix-with-CrystalCPU

Will post instructions after I test it out.

Of course, the root cause is still the bug in the Macbook EFI. Until Apple issues a fixed EFI, this could be a useful workaround.

--- THIS WORKAROUND IS FOR THE MACBOOK AIR 2012 with i7 CPU ONLY ---

This is a scripted (one-click) approach to implement the MSR fix that tori10love found.

1. Download and install the latest version of the program RW-Everything, v1.4.9 at this time:

http://jacky5488.myweb.hinet.net/download.html

By default it installs to C:\Program Files (x86)\RW-Everything\

2. Create a text file which is the script, that has this:

>cpu 1

>wrmsr 0x00000199 0 0x00002000

>cpu 2

>wrmsr 0x00000199 0 0x00002000

>cpu 3

>wrmsr 0x00000199 0 0x00002000

>cpu 4

>wrmsr 0x00000199 0 0x00002000

>rwexit

For example, I created this file as C:\Temp\MacbookAir2012_i7_Fix.rw

3. Create a CMD/DOS batch file which runs this script:

cd C:\Temp\

"C:\Program Files (x86)\RW-Everything\RW" /Command=MacbookAir2012_i7_Fix.rw /Logfile=rw-logfile.txt

--- DONE ---

Note that the MSR value is reset to the default (wrong) values after every SLEEP or BOOT. So if you want this to be always fixed, it has to be run after every wakeup or boot.

My current solution to this is to use VMware Fusion to run Windows under a virtual machine from OSX.

The beauty of this approach is that Fusion can run your existing Bootcamp partition so there's no need to do anything other than install Fusion and set it up. Your Windows stuff stays exactly where it is. (Maybe Parallels is the same way, I don't know.)

I was worried about the performance hit since I do some C# development with Visual Studio and my applications can be CPU (but not graphics) intensive. They seem to run without a noticable performance hit vs. an identical Macbook Air using Throttlestop to enable Turbo boost.

So unless you need intensive graphics this could be a good solution, with the added bonus of not having to reboot to switch between OSX and Windows. It works fine with Mountain Lion too.

If I find any drawbacks or any applications that don't run correctly I'll post back.

John