1 (edited by fl 2009-09-05 14:34:21)

Topic: Bootcamp 3.0 and DPC Latency Issues

My initial foray into Bootcamp 3.0 has ended with failure, and I am now restoring my Windows partition from a cloned backup - thank you Winclone!

Bootcamp 3 is installed from the Snow Leopard installation disk under Windows (XP SP3 in my case), and consists largely of newer drivers for all the Mac hardware.  I found that the drivers installed by Bootcamp 3.0 for the NVDIA video and RealTek audio hardware (earlier versions were troublesome) are fairly recent, but not as new as the versions of the drivers that can be found on their respective company's websites.  Even after updating those drivers (which has usually resulted in reduced DPC Latency performance in the past under Bootcamp 2.0), I was still getting huge DPC spikes when viewing the system's performance in DPC Latency Checker.  My first thought was that the Apple Keyboard Manager (KBDMGR.EXE) got reinstalled, but I couldn't find it in the Windows Task Manager, or MSCONFIG, so maybe Apple has renamed this program which typically causes large DPC spikes every 30 seconds or so.  To tell the truth, I deleted KBDMGR.EXE from my system a very long time ago - so long that I can no longer remember where it was located in the first place, and using Windows' Search utility yields no results with that file name.  I thought that Bootcamp would re-install it, but I can't find it for the life of me.  I have never used Timur's Keyboard Manager switcher, but I'd imagine that this might not work anymore following a Bootcamp 3.0 install.

I have a Windows utility program that is designed to examine all device drivers and search out the newest updates for them all (Driver Checker), and found that after doing the Bootcamp 3.0 install, there were several Intel drivers that needed updating, so clearly Apple has included drivers that may have been current some months ago, but have now been superseded by more recent issues.

I'm sure there is a host of other optimizations that can be done to bring Bootcamp 3's performance to the status I was able to manage previously, but really, who needs the aggravation?  If there are no clear problems with running my Bootcamp 2.0 install with updated hardware drivers, then I'm thinking that I may just leave well enough alone.

At least until Windows 7 becomes a necessity for running a future version of Pyramix...

Has anyone else had any differing experiences with Bootcamp 3.0?

Frank Lockwood
https://LockwoodARS.com
Fireface 800, Firmware 2.77
Drivers: Win10, 3.125; Mac, 3.36

2

Re: Bootcamp 3.0 and DPC Latency Issues

fl wrote:

My initial foray into Bootcamp 3.0 has ended with failure, and I am now restoring my Windows partition from a cloned backup - thank you Winclone!

I discovered that there is an issue with Winclone 2.2.  Restoring a cloned partition that was made under Mac OS 10.5, while running OS 10.6 corrupts some of the key Windows components, so that the restored partition will have problems.  I fought with this for two days, until finally I booted from my bootable Carbon Copy Cloner backup of my last day's 10.5.8 installation, and ran Winclone from there - then my restored Windows partition ran fine and I was able to apply NVDIA and RealTek updates without issue, and install the new version of Pyramix.

So, in summary:  Bootcamp 3.0, which comes with Mac OS 10.6 Snow Leopard, installs many hardware drivers (too many to keep track of, as they go flying by on install), and software which increase DPC Latencies to unacceptable levels for audio work.  Searching for Apple's Keyboard Manager (KBDMGR.EXE) yielded no results, but I suspect from the timing of the DPC spikes, that it was installed somewhere and is responsible.  Restoring my partition from a Wincloned backup resulted in a unstable Windows XP SP3 installation, when Winclone was run from Mac OS 10.6.  Running Winclone in OS 10.5.8 solved that problem.

Basically, if you have a stable, low latency Bootcamp 2.0 install, and have updated hardware drivers through their own companies' websites (particularly for NVIDIA), don't bother with Bootcamp 3.0, unless you really enjoy spending time tracking down sources of high DPC Latency.

Frank Lockwood
https://LockwoodARS.com
Fireface 800, Firmware 2.77
Drivers: Win10, 3.125; Mac, 3.36

Re: Bootcamp 3.0 and DPC Latency Issues

As far as I know from reports about the Bootcamp 3.0 beta KBDMGR.EXE was renamed into BOOTCAMP.EXE. I will not buy Snow Leopard before next week so I cannot check myself yet.

4

Re: Bootcamp 3.0 and DPC Latency Issues

Looking forward to reading what you find, Timur.

Frank Lockwood
https://LockwoodARS.com
Fireface 800, Firmware 2.77
Drivers: Win10, 3.125; Mac, 3.36

5 (edited by fl 2009-09-28 23:28:43)

Re: Bootcamp 3.0 and DPC Latency Issues

Timur wrote:

As far as I know from reports about the Bootcamp 3.0 beta KBDMGR.EXE was renamed into BOOTCAMP.EXE.

I put in a call to Applecare, to find out just what gets installed where with the Boot Camp 3.0 installation.  It was strongly recommended to me to run with the BC 3.0 package if I'm running Snow Leopard on my other partition, but as I mentioned in the posts above, I've been holding off because of the DPC Latencies I found with the new drivers.  However, because I've encountered my MacBook Pro (late 2007) running hotter than I remember it doing - mostly due to graphics processing (NVDIA hardware), I was also trying to learn whether the Boot Camp 3.0 installation would provide any improvement with the temperature regulation.  Applecare was careful to not come right out and say anything definitive about this, but again, it was strongly hinted that upgrading to 3.0 would allow things to run better, and possibly, cooler.  I should also mention that I am running Windows XP Pro SP3.

I was able to find out that kbdmgr.exe has been renamed to APPLEOSSmgr.exe, so hopefully disabling this executable will give the same reduction in DPCs as was found with what we all wound up doing with BC 2 and 2.1.  Applecare was quick to point out that disabling this puts you outside of what they're willing to support on the Windows side..., you do so at your own risk, yadda, yadda....

Other information about what drivers come in the 3.0 package can be found here:
http://support.apple.com/kb/HT3777
but I'll quote the pertinent information:

Which drivers are included on the Mac OS X 10.6 (Snow Leopard) DVD?

The Mac OS X 10.6 (Snow Leopard) DVD contains the following Mac drivers for Windows:

Apple Bluetooth
Apple Keyboard Support
Apple Remote Driver
Apple Trackpad
Atheros 802.11 Wireless
ATI Graphics
Boot Camp control panel for Microsoft Windows
Boot Camp System Task Notification item (System Tray)
Broadcom Wireless
Intel Chipset Software
Intel Integrated Graphics
iSight Camera
Marvel Yukon Ethernet
nVidia Graphics
Cirrus Logic Audio
Realtek Audio
SigmaTel Audio
Startup Disk control panel for Microsoft Windows


and of course the Instructions for setting up Boot Camp 3.0 on an Intel Mac can be found here:
http://manuals.info.apple.com/en/Boot_C … -Setup.pdf

Frank Lockwood
https://LockwoodARS.com
Fireface 800, Firmware 2.77
Drivers: Win10, 3.125; Mac, 3.36

Re: Bootcamp 3.0 and DPC Latency Issues

I bought SL yesterday and will give the new Bootcamp drivers a run soon. I will also update my scriptfile then.

Furthermore I will contact Apple 2nd level support again (now that my logic board was replaced without any benefit) and once we got through all the other problems I will adress the driver issues again.

Obviously this all will take some time depending on how fast Apple reacts.

7

Re: Bootcamp 3.0 and DPC Latency Issues

Timur,

Just wondering if you've had a chance to look at Boot Camp 3.0 yet, and what the verdict is about BOOTCAMP.EXE and/or APPLEOSSmgr.exe?  Have you had a chance to update your script?

Frank Lockwood
https://LockwoodARS.com
Fireface 800, Firmware 2.77
Drivers: Win10, 3.125; Mac, 3.36

Re: Bootcamp 3.0 and DPC Latency Issues

I have same issues.
It doesn't matter wether i disable network adapters or not.
I disabled AppleOss but without success.

Re: Bootcamp 3.0 and DPC Latency Issues

On Macbooks (Pro) the Bootcamp 3 drivers behave the same as the 2.1 ones. So all of my advices about how to get low DPCs are still valid.

Interestingly though the BOOTCAMP.EXE does *not* cause any problems on the new Imacs even when it is the same drivers. So the combination of Macbook and driver is the culprit.

Furthermore the "Atheros" WLAN drivers on Imacs cause a spike every 60 seconds which can only be changed to every 10 minutes via device-manager. Using the driver from Microsoft Update Catalog does not help with the Atheros.

The "Broadcom" WLAN drivers for Macbook (Pro) from Microsoft Update Catalog are still the best choice even while the Bootcamp 3 ones are alot better than the older ones and seem to be more recent the the MS ones.

NVidia drivers issues for 9600M GT are still not fixed, but there are no such problems for the 9400M GT in the IMac. I had no chance to check any Macbook NON-Pro about that.

Re: Bootcamp 3.0 and DPC Latency Issues

It's definitely a difference running Windows on a Bootcamp drive on a MacBook or any other machine.
I run Win XP Pro SP3 on my Mac Pro and on a MacBook.
The Latency Tool shows values of about 2900 ? for the Mac Pro (idle, 3500 when running SAM 11 Pro) and less than 1000 ? for the MacBook.

On My Mac Pro it doesn't help stopping Bootcamp process and there's nearly no difference if i disable network adapters or not.

I don't get it.

I think i did a lot to optimize my system.

But there's no difference. It's still performing quiet bad.

What is it???

Re: Bootcamp 3.0 and DPC Latency Issues

Go to the "Tips & Tricks" section and read my post about how to get low DPCs on Macbook Pro. It's probably a problem with graphics.

Re: Bootcamp 3.0 and DPC Latency Issues

Hello Timur,
iread your post. I checked all drivers, they are up to date. I disabled wlan driver although latest broadcom drivers are installed. I used rivatuner to tweak graphics. But i still get same high values on Mac Pro!

MacBook is performing well. I get values between 80 and 120 milliseconds with wlan disabled.

Re: Bootcamp 3.0 and DPC Latency Issues

Christoph wrote:

MacBook is performing well. I get values between 80 and 120 milliseconds with wlan disabled.

This is not the whole truth.

Actually i have bigger problems with my MacBook. The values seem to be good but i have huge latency when using firewire.

I checked the registry for sidspeed values. Seems to be fine.

Re: Bootcamp 3.0 and DPC Latency Issues

I found out that the Intel LAN-adapters together with the bluetooth-adapeters are causing DPC-spikes. Disabling both LAN-adapters reduces Latency from nearly 3000 ? to about 250 ?. Additionally disabling both bluetooth-adapters improve latency to 70 - 200 ?.

But i'm still far away from my Mac-performance.

15

Re: Bootcamp 3.0 and DPC Latency Issues

There's something about the laptops...

I find that my fully tweaked XP SP3 installation can get down to between 5 and 12 micro-seconds on my iMac, when I unplug all the non-essential USB connections (hub, printers, SD card reader).  On my MacBook Pro (late 2007), the lowest I can get is somewhere between 80 and 120 micro-seconds.  Both machines have all wireless communications (including Bluetooth) disabled.  There are, however, differences in the graphics hardware (NVDIA 7600 GT in the iMac, 8600 GT in the MBP), and of course, there is the more complex powering control because of the battery in the laptop.

There are times I wish I had gotten the smallest iMac instead of the MBP for portable/location work.  One of those and an iLugger case are pretty portable.

Frank Lockwood
https://LockwoodARS.com
Fireface 800, Firmware 2.77
Drivers: Win10, 3.125; Mac, 3.36

Re: Bootcamp 3.0 and DPC Latency Issues

fl wrote:

There's something about the laptops...

I find that my fully tweaked XP SP3 installation can get down to between 5 and 12 micro-seconds on my iMac, when I unplug all the non-essential USB connections (hub, printers, SD card reader).  On my MacBook Pro (late 2007), the lowest I can get is somewhere between 80 and 120 micro-seconds.  Both machines have all wireless communications (including Bluetooth) disabled.  There are, however, differences in the graphics hardware (NVDIA 7600 GT in the iMac, 8600 GT in the MBP), and of course, there is the more complex powering control because of the battery in the laptop.

There are times I wish I had gotten the smallest iMac instead of the MBP for portable/location work.  One of those and an iLugger case are pretty portable.

Tweaking the graphics din't improve anything on my Mac Pro but what other tweaks did you apply? I studied all the informations given in this forum or from the focusrite website but i still have too much latency.

I cannot play my bass through a virtual amp without disturbing latency. Under Mac OS i never had trouble to do so.

Re: Bootcamp 3.0 and DPC Latency Issues

DPC times of around 100 us are already perfect, anything lower is just a bonus that wont have any much of an effect. In fact, anything upto 300 us should not be noticeable as long as your audio application uses a high enough priority.

This is because according you can reach in Windows seems to be 1 ms (=1000 us) and you have to be kind of unlucky to have other drivers/applications cause DPC just the moment when the audio driver transfers the next buffer. Because the audio buffer is transfered at a regular interval while other drivers/applications may issue DPCs in irregular intervals it can happen though.

DPCs have higher priority than any software process/thread (even realtime ones), but keeping other processes from accessing drivers/hardware while the audio application is busy also keeps them from interfering with the audio driver.

18

Re: Bootcamp 3.0 and DPC Latency Issues

Christoph wrote:

Tweaking the graphics din't improve anything on my Mac Pro but what other tweaks did you apply?

The only other thing I do is to disable the drivers for the internal sound hardware, when I'm running my DAW with my Fireface.  When Boot Camp 2.0 first came out, the RealTek drivers Apple provided had a serious conflict with the Fireface drivers, and would cause a hang on shutdown.  Updating to more recent RealTek drivers fixed this, but I got into the habit of disabling the internal sound stuff.  I also disable the built-in camera on the MacBook Pro and the iMac.

When I do a location recording with the MBP, I disable the Marvell Network driver, which is what allows the machine to connect to the internet via Ethernet.  (When I'm on location, I'm not connecting to the internet.)  It seems to be a good idea to disable any networking drivers - wired or wireless - when running audio processes, to reduce DPC interruptions.

There are many Services which Windows runs, which can be modified to run Automatically, or only when called (Manual Mode).  A search on Google should provide links to many sites with ideas for optimizing Services, but here are some recommendations:
http://tweakhound.com/xp/xpservices.htm
http://tweakhound.com/xp/xptweaks/supertweaks1.htm
http://www.blackviper.com/WinXP/servicecfg.htm

Frank Lockwood
https://LockwoodARS.com
Fireface 800, Firmware 2.77
Drivers: Win10, 3.125; Mac, 3.36