Is there any way to programmatically disable Turbo Boost on a Core i7 mac running Mac OS X ? I need to be able to do this for benchmarking purposes during code optimisation etc. Failing that, any kind of utility which can disable/enable Turbo Boost, even if it requires a reboot, would be useful.
There is a related question (not Mac-specific) on SO: How to turn off Turbo Boost temporarily? but even for PCs it seems that there may be no way to do this programatically/on-the-fly ?
I wrote kernel extension that let's you disable TB, have fun:
https://github.com/nanoant/DisableTurboBoost.kext
If you want to disable TB on Linux here another recipe: http://luisjdominguezp.tumblr.com/post/19610447111/disabling-turbo-boost-in-linux
I've just coded an app that allows to load / unload the kernel extension mentioned before, helping to track the system behaviour displaying CPU Temp & current fan speed.
You can check it out here https://github.com/rugarciap/Turbo-Boost-Switcher
Here is an screenshot of how it looks like http://i.stack.imgur.com/tsKaG.png
You can't. Certain stuff needs to be configured from the BIOS, such as TurboBoost or Vt.
In particular, this is done with the IA32_FEATURE_CONTROL MSR. On a PC, at boot time the MSR is unlocked and the BIOS sets the correct bits to enable or disable features. Once configuration is complete, the BIOS locks the MSR for the changes to take effect and prevent future modification.
I don't know if it's possible to unlock the MSR again before the PC is brought into protected mode, and I don't know how this works on a MacBook where EFI is used instead of BIOS. You'll probably be able to pull it off with an EFI extension of sorts.
CPUID.com's Tmonitor utility can disable/enable Turbo Boost on-the-fly from within Windows, not at boot! There must be a way to do the same thing from within OSX.
Finally there seems to be a good solution for this problem which I have tested with Mac OS X Lion on a Core i7 MacBook Pro today and it appears to work well. Adam Strzelecki, a researcher in parallel computing at Jagiellonian University in Krakow, Poland has written DisableTurboBoost.kext - this is a small kext which can be loaded and unloaded at will (via the command line) to disable/enable TurbBoost.
Related
I've wanted to install docker on my windows. I'm getting an error. Hardware assisted virtualization and data execution protection must be enabled in the BIOS. See . I can't go to my bios, after pressing f2 i have just a black screen, i tried to restart my computer manually and from windows in advanced settings from tutorials. In task manager my virtualization is off, I checked my Cpu supports virtualization on Intel Processor Identification Utility and it is. My Cpu is i7 4770k 3,5Ghz. I downloaded bios update for my motherboard but I know, I have to put it on my Pendrive and open it from my bios, couldn't install it straight from my pc with .CAP extension. My motherboard is Asus Z97M-PLUS. I tried to set my virtualization without bios with tutorials, PowerShell commands, changing settings, avast, hyperV. Can't describe exactly what I was doing and which commands I was putting in because I tried everything I found.
It is difficult to help you in this case as this is a very case-specific problem, especially hardware specific. The fact that you can't enter your bios will make enabling virtualization very difficult, as this switch must be switched there, and only there. I suppose you could try resetting your BIOS by shorting two pins / pressing a button on your motherboard, to see if that makes it want to open again.
Try this motherboard manual document at section 1.2.6 and 1.2.7 depending on your use case.
Furthermore, this website probably is not the best place to ask these sort of questions, and tech forums would probably be better able to help you further.
Background
I've been bouncing around this for a while and still haven't come up with an adequate solution, hoping someone out there can point me in the right direction.
Essentially I need to identify whether I can run 64bit VM on a target machine (working in GO but happy to consider binding c code or some assembly (though I feel a bit out of depth there)
In order to run a 64 bit VM the system need Hardware Virtualisation support available and enabled in the bios (im only concerned with intel/amd at this time)
Journey so far
From windows 8 onwards, Windows ships with Hyper-V, and there is a nice function you can call IsProcessorFeaturePresent from the kernel32.dll with an arg of 'PF_VIRT_FIRMWARE_ENABLED' which will tell you if hardware virtualisation is enabled in firmware:
IsProcessorFeaturePresent
now I dont really like the way this behaves (it says not available if hyper-v is installed) but i can cope with it by checking if hyper-v is enabled through other means so this pretty much does the job from win8 upwards.
Problem is this function always return false on win 7 for some reason - even on a system on which I know hardware virtualization is enabled.
Coming from another angle I have used this lib to determine what instruction sets are available: intel processor feature lib - this allows me to know what type of virtualization instructions are available on the processor (if any)
But I'm still missing the final piece of knowing if its enabled in the bios on win 7. I figure in principle it should be easy from here - I should be able to call something which utilizes the virtualization extensions and see if it responds as expected. But unfortunately I have no idea how to do this.
Does anyone have any suggestions as to how I might do this?
Note: Im happy to consider 3rd party libs but this would be used in commercial software so licensing would have to allow for that (e.g nothing from Microsoft)
I am afraid you won't be able to achieve what you want unless you are ready to provide a kernel driver, because checking if BIOS has enabled virtualization requires kernel privileges.
Intel Software Developer Manual describes a model-specific register (MSR) with number 3Ah called IA32_FEATURE_CONTROL. Its bits 1 and 2 control whether VMX instructions are allowed in SMX and non-SMX modes. Also there is bit zero which, when written with 1, locks the whole register's value, thus making impossible to enable/disabled features until the next processor reset. This means that, if BIOS code has disabled VMX and locked it, an OS that boots later will be unable to change that fact, only to see it.
To read this or any other MSR one should use machine instruction RDMSR, and this instruction is only available when CPL is zero, that is, within an OS context. It will throw an exception if attempted to be used from application code.
Unless you find a program interface method that wraps RDMSR around and provides it to applications, you are out of luck. Typically that implies loading and running a dedicated kernel driver. I am aware about one for Linux, but cannot say if there is anything for Windows.
As an extra note, if your code is already running inside a virtual machine, like it is for some Windows installations which enable a Hyper-V environment for regular desktop, then you won't even be able to see an actual host MSR value. It will be up to the VMM to provide you with an emulated value, as well as it will show you whatever CPUID value it wants you to see, not the one from the host.
I am kinda new to Android Studio & stuff. So today, I was installing the Android Studio with the SDK Manager. All was going smooth until an error came up which says:
Unable to install Intel HAXM
Your CPU does not support required features (VT-x or SVM).
Unfortunately, your computer does not support hardware accelerated virtualization.
Here are some of your options:
Use a physical device for testing
Develop on a Windows/OSX computer with an Intel processor that
supports VT-x and NX
Develop on a Linux computer that supports VT-x or SVM
Use an Android Virtual Device based on an ARM system image (This
is 10x slower than hardware accelerated virtualization)
I've attached a pic of my system specs. Can someone please throw some light on this issue?
Thanks
It is because you had not intialize virtual technology in your device.You Need to go in BOOT Option before starting WINDOWS OS and enable VT-x from there>
The option of enabling Virtual technology is putted in different option depends on device manufacturer
Edit: Android Studio emulator won't run on Windows with an AMD processor. The error message is kind of misleading, as it suggests the problem is with your CPU. But it is within the troubleshoot message: "Windows/OSX computer with an Intel processor". Basicallly, that means it is not going to work properly in your current setup. Either try installing Linux and running Android Studio on that (which might come with its own issues), using a physical device for testing or use the slow ARM images.
You are using an AMD processor. SVM is AMD technology and VT-x is Intel technology. So you won't be able to get VT-x to run, but SVM might be possible.
As another poster had suggested, virtualization may have been disabled in the BIOS. There may be an option to enable virtualization. It does however seem to happen that virtualization is activated in the BIOS and Android-Studio does not recognize that. I have not figured out how to fix that either.
You could use the emulator with an ARM image, which will be very slow. Alternatively, you could use another emulator that is not integrated into Android-Studio.
I've a C++ program and I would like to quantify it's performance by checking the number of hits and misses against the CPU cache.
What's the best way to do it?
I tried using Intel's Performance Counter Monitor but it uses an unsigned Kernel Extension which are disabled on Yosemite. I can obviously disable the check to not load unsigned kexts but I wouldn't like to go down that path.
Is there any other possible way that I'm unaware of?
You can enable unsigned kernel extensions with OS X (reboot afterwards required):
sudo nvram boot-args=kext-dev-mode=1
This enables developer mode on your machine and you can run Intel Performance Counter Monitor as long at it supports Mac OS X 10.10 (Yosemite) in general.
Don't forget to disable it again after you are done with testing (security-issue otherwise):
sudo nvram boot-args=kext-dev-mode=0
As far as I know Intel's tool is far better than cache grind because it uses actual counters from the hardware instead of simulating an cpu and it's cache characteristics in software.
You could, in principle, apply for a kext signing certificate, if you're an Apple developer programme member, and sign the kext yourself. But they generally don't hand them out for internal use, and recommend you enable kext-dev-mode or disable SIP (depending on version). Another good path would be to ask Intel to provide a signed version of their kext!
I am using Turbo C 3.0 and Turbo c 2.0 for the programming. Added to this I am using Windows XP. While using Windows 98, the above said programs were really worked fine. But after installing XP, those programs were really slow-down my system. Those were really using high CPU power even when idle(idle refers to "no interaction between program and user").
Can anybody previously solved this issue, Post here.
Also, I want to know what is causing those slow-down!
Those are 16 bit DOS programs, and they probably will not run on XP. They are probably running in the NT Virtual DOS Machine. Use the task manager, or better yet, Process Explorer, to check this. You will probably not see your programs running; look for instances of ntvdm.exe instead.
I have noticed several antivirus programs (Checkpoint, Proventia Desktop) seem have a problem with ntvdm. It is as if they eat up quite a bit of cpu when an ntvdm instance is running.
Also, wasn't Turbo C finicky about its extended memory settings? If you still have your Autoexec.bat and Config.sys files from the Win98 system, you could try changing XP's settings to match. The XP equivalent to these files are autoexec.nt and config.nt; they are in the Windows\System32 directory.
I suspect Adrian's comment is the correct answer: old DOS programs did not account for multitasking and so tended to put themselves in tight loops when "idle". Back in the day, it didn't matter as nothing else was running at the same time and the operating system would interrupt the running program to handle hardware, well, interrupts.
I would highly recommend avoiding such tools on modern hardware because the programs the generate are likewise not multitasking friendly. They are also going to be optimized for ancient processors and have limited memory addressing. If you have some old hardware and want to goof around with it, then knock yourself out. But there are plenty of modern compilers that are free (either as Visual C++ Express is to get you hooked, or open source).
This can be avoided partially by setting process priority.
Start the App eg. Turbo C++ 3.0
Minimize and go to Task Manager
Find ntvdm.exe
Right Click > Set Priority > Low > Yes
Then it runs with not so annoying speeds.