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MBA2012 CTO model is turbo boost disable under windows 7

T

tori10love

macrumors newbie
Original poster
Jun 21, 2012
6
0
i purchased MBA2012 CTO Corei 7 2.0GHz/ MEM 8GB / SSD 128GB.

core i7 3667U, it support turbo boost, max multiplier 3.2GHz (x32, 1core), or 3.0GHz(x30, 2core).
but check cpu-z 1.60.1.x64, it reports cpu multiplier x8 or x19. core speed does not reach 2.0GHz(x20).

CPU-Z.png


proccesor score of windows 7 experience index. MBA2012 CTO model's score is very low:mad:.

MBA2011 CTO Core i7-2677M 1.8GHz(TB 2.9GHz) 6.9
MBA2012　　　　　Core i5-3317U 1.7GHz(TB 2.6GHz) 6.9
MBA2012 CTO Core i7-3667U 2.0GHz(TB 3.2GHz) 6.3

i think MBA2012 Core i5 is enabled turbo boost, but MBA2012 CTO Core i7 is disabled trubo boost, guess cpu max multiplier setting is wrong, and turbo boost is disabled in EFI to change boot windows.

--
workaround(method): use ThrottleStop 4.0 later

http://www.techpowerup.com/158795/TechPowerUp-Announces-ThrottleStop-4.0.html

TRL(Turbo Ratio Limits) set to Maximun Turbo Ratio Limits. 1 core active 32/ 2core active 30.
i have confirmed improvement that proccesor sore on windows7 experience index is up to 7.1.

TRL.png


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i guess this bug is a problem of setting the MSR (IA32_PERF_CTL:Target performance State Value) in EFI.

it is assumed in the model CTO in the initialisation of the MSR in EFI, is to set the Target P-State and 19 at the time of turbo boost, and the root cause of the bug (I originally set 32 ​​is correct).

MSR 0x00000199 0x00000000 0x00001300 (bad)
MSR 0x00000199 0x00000000 0x00002000

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workaround(another method): use MSR Editor (CrystalCPUID)

http://crystalmark.info/software/CrystalCPUID/index-e.html

run CrystalCPUID.exe, Function->MSR Editor, set values and press WRMSR. repeat CPU1-CPU4.

MSR Number 0x00000199
WRMSR EDX-> 0x00000000 EAX-> 0x00002000

MSR.png

---
fixed!!

MacBook Air EFI Firmware Update 2.5
http://support.apple.com/kb/DL1592

This update is recommended for MacBook Air (mid 2012) models. This update fixes an issue where Turbo Boost does not activate when using Boot Camp, and resolves an issue where NetBoot does not function properly when using an Ethernet adapter.
 
Last edited:
I've noticed this, too and filed a bug report with Apple. I also alerted AnandTech in case he sees it in his review of the i7.
 
KPOM said:
^This. On the 11" model you can get an i7 with 128GB, 256GB, or 512GB. On the 13" model the i7 is available only on the 256GB and 512GB models. It was the same last year (except there was no 512GB option).
Click to expand...

Indeed, hope Apple fix this soon, have just (yesterday) ordered an i7/8Gb RAM/256Gb SSD 13" MBA...
 
anthdci said:
How did you do that, the i7 is only available on the 256gb version.
Click to expand...

my macbook air is 11inch model. core i7 on mba 2012 11inch is avaiable on 128gb/256gb/512gb.

i confirmed that MBA2012 core i5 standard model is enabled turbo boost, but core i7 cto model is disabled turbo boost, and reported this bug to apple support.

apple support replied that apple also confirmed this bug, will plan to fix firmware in the future.
 
Hum... as Turbo Boost is a processor feature and depends directly to the EFI, can we assume that this is NOT enable at Mac OS X either ? Is there a way to verify that ?
 
Monkeyat said:
Hum... as Turbo Boost is a processor feature and depends directly to the EFI, can we assume that this is NOT enable at Mac OS X either ? Is there a way to verify that ?
Click to expand...

Given that the published benchmarks so far indicate that the i7 MacBook Air is about 10-20% faster than the i5 models (see Macworld), it's a safe assumption that Turbo Boost is just fine in OS X.

The Air was released before the Boot Camp drivers were available. What Boot Camp does is "translate" the Mac's EFI into BIOS-type instructions. My guess is that something in the EFI firmware doesn't translate right in Boot Camp and will need to be updated.

On a side note. although Windows 7 and Windows 8 support UEFI, it's a newer implementation than Apple's EFI, and Apple is unlikely to switch to it in the near future since a customized EFI helps them keep OS X exclusive to the Mac.
 
Aha!

I had suspected this as there's an emulator I use that is heavily CPU reliant and performed about as well as my older MBA, I though something like this may be the case, hope it's addressed soon.

Old MBA: 13" i5
New MBA: 11" i7
 
goinskiing said:
I had suspected this as there's an emulator I use that is heavily CPU reliant and performed about as well as my older MBA, I though something like this may be the case, hope it's addressed soon.

Old MBA: 13" i5
New MBA: 11" i7
Click to expand...

Tori10Love posted on the Apple Support Forum and another thread here that Apple has acknowledged the issue and will address it in a firmware update.

Also, Anand Lal Shimpi returned my e-mail and will look into it over the weekend, so it should get some coverage.
 
i can confirm that turbo boost does NOT work under boot camp

i own both a 2011 air and a 2012 air with the top-end processors.

i can confirm through geekbench and wei scores that the turbo boost is not engaging under boot camp.

turbo boost appears to be working on the OS X side as Geekbench scores are noticeably faster than last year's model.

I am glad to see others have this issue and apple has confirmed. I guess I will patiently await a fix.
 
Wrote this on the other forum:

I can confirm this as well on my 11" i7 8GB/256GB. I get the same Windows score of 6.3 whereas my 13" i5 scored 6.9. I hope it dones't take to long to address as it's a fairly simple toggle in the EFI, they probably have to run some regressions first though to make sure nothing else breaks I'm sure. There are definitely applications I use that use the turboboost and one of the reasons I went with the i7 option.
 
goinskiing said:
This should probably be a page 2 or maybe page 1 things where users are reporting turbo mode on core i7 MBA's disabled.
Click to expand...

Yes, this is quite a serious issue - at the moment it means users are paying more for a product that is potentially slower (albeit under a non Mac OS) than a cheaper model!
 
tori10love said:
turbo boost is disabled in EFI to change boot windows
Click to expand...
I see no EFI-problem. The OS kernel detects and enables hardware-specific features, so this is a Windows/Intel CPU driver problem. It is possible that your current version of Windows or your current version of Intels CPU drivers is not compatible with your new hardware. Make sure you install ALL available Windows-updates (autoupdate), Windows Service Packs (SP) and the newest Intel drivers. Do not use (older) Boot Camp drivers!

Btw:
Intel® Turbo Boost Technology Monitor

Another piece:
Doc_SilverCreek said:
http://communities.intel.com/thread/11604

In Windows 7 / 2008, your power management should be set for balanced mode not preformance.
(sounds strange but performance mode can cause the the cpu to stay at its max rated frequency rather than clocking up to turbo boost mode)
Click to expand...
.
 
Last edited:
Mr. Retrofire said:
I see no EFI-problem. The OS kernel detects and enables hardware-specific features, so this is a Windows/Intel CPU driver problem. It is possible that your current version of Windows or your current version of Intels CPU drivers is not compatible with your new hardware. Make sure you install ALL available Windows-updates (autoupdate), Windows Service Packs (SP) and the newest Intel drivers. Do not use (older) Boot Camp drivers!
Click to expand...

I'm using Apple's latest drivers. I think the issue is that for some reason the driver was updated for the i5 ULV CPU but not the i7. It appears to be on Apple to resolve this, and if it's a driver issue it should be an easy fix.
 
i returned my air and stated this as the reason

i doubt the apple service agent even knew what i was talking about but at least he wrote it in his notes.

now i am testing a macbook pro to see if the issue is present there.

i will respond again when i confirm.
 
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