(original post from 8/14 follows, before Boot Camp 1.1 was released)
A follow-up to the earlier post on Mac Pro Windows XP drivers, slow performance/PIO mode with onboard SATA. Unfortunately Mac Pro owners wrote that only PIO mode is working.

" Mike, Inform your readers that DMA for SATA drives is disabled by default for some reason under Windows XP. (Note: I don't think this is universally true, and a MacBook Pro owner wrote his Bootcamp/Windows XP install used UDMA mode on the internal SATA bus. However currently Mac Pro owners running XP all reported PIO was being used, resulting in poor performance of onboard SATA drives.-Mike) A colleague informed me of a significant boost in disk i/o when DMA is switched on.

While running Windows XP, go to the Control Panel, and double click the System control panel.

1) Click the Hardware tab, and then the Device Manager button.
2) Click the reveal (+ sign) on IDE ATA/ATAPI Controllers
3) select either Primary IDE Channel or Secondary IDE Channel, right click, select "Properties".
4) Select the Advanced Settings tab, and note the settings for the devices listed. "DMA if available" should be selected in the Transfer Mode pull down. (Mac Pro users reported currently PIO is used on their installs, even after installing Intel chipset driver/updates-Mike)
Click Ok on that dialog, and then Ok on the System control panel. I don't know if you will need to restart XP, but it might be wise to do so.

Here's some links to MS support concerning Windows' default use of PIO after multiple timouts/crc errors:
http://support.microsoft.com/default.aspx?scid=kb%3Ben-us%3B817472
-Eric M."

A Mac Pro owner replied to this post saying the selection "DMA if available" was already selected, but still didn't change the mode actually used:

"I went into XP under Boot Camp and indeed the SATA channels show they are in PIO mode.

However, the drop down selection on both is "DMA if available". The only other choice I can change them to is "PIO only" which, of course, I don't want. (it's already running in PIO mode)
So for now, DMA isn't available, and that is what slows it down dramatically.
Win XP SP2 corrected the CRC errors causing a drive to drop into PIO problem according to the KB article (linked above)...
-Paul "

I asked Paul if he was sure CRC errors were detected. (The Microsoft Kbase doc linked to above is from 2003, it mentions a service pack/hotfix (which should already be in XP SP2 installs, which are required for BootCamp) and a workaround procedure (delete driver, reset registry error counter, then reboot/redetect controller) *if* CRC errors were the cause of PIO mode being used. (NOTE: Before messing with the registry, create a System Restore point in Windows XP in case something goes wrong.)
Deleting the existing driver and rebooting/re-detecting (reinstalling driver) is worth a try however.
If someone finds a fix for this issue (updated drivers, registry mods, etc. let me know.
Apple's bootcamp page also asks to send feedback to bootcamp@apple.com to help improve future versions, so Mac Pro owners should write them about issues like this. (I suspect they are already working on an update for the Mac Pro but it can't hurt to report things like this.)

" Mike, Made the plunge and got the Mac Pro. I will update you with some findings when I am done. For your readers with a Mac Pro here is list of working drivers for it: (including Intel motherboard chipset drivers, Nvidia 7300 drivers, audio, etc.)
http://discussions.apple.com/thread.jspa?threadID=596874&tstart=0
It runs GREAT and Windows as well.
-William R. "

I sent this link to a reader w/Mac Pro running XP who said performance with the SATA drive was very poor, a common complaint he said (PATA drives were OK/much faster). I asked he check device mgr to see what it showed for the controller and HD, as I suspected a driver or mode issue. He later wrote he was already using the drivers listed in the apple thread (didn't help) and reading the posts down that thread it mentions onboard SATA performance is still poor. (Interface running in PIO mode)

" Yes sorry, I forgot to mention that this won't help the SATA speed at all. I slapped a PATA drive in my system and I'm just running off of that for XP. PATA is much faster. When they figure out the SATA stuff, I'll ghost my PATA drive to a SATA drive and be done with it. "

A later post in the thread mentions Windows XP's device mgr shows the SATA drives in PIO mode (not UDMA):

" I will tell you this... it's related to the SATA drives transfer mode being in PIO instead of UDMA. If you go into device manager and take a look at the properties of your "Primary IDE" channels, click on "Advanced Settings", you'll see the "Current Transfer Mode" will say PIO for your SATA HD's.
To me it looks like a driver issue, but also a problem with the EFI/bios hooks detecting the proper transfer modes of the HD. (on PC motherboards you can check/change mode settings of onboard Controllers in the Bios-Mike)
It gets even more interesting if you try to use the PATA channel. My PATA HD will show up as UDMA mode 5 if I hook it up as a Master on the PATA channel. If I hook it up as a slave with the DVD drive on Master, the DVD drive shows up as UDMA 5 and the HD as UDMA 0. If I hook up the HD as a master and the DVD drive as slave, my HD shows up as UDMA 5 and the DVD drive is UDMA 2. However, when the DVD drive is on slave, I can't eject properly from OSX. F12 and also the eject menu option don't do anything (even tried option-eject, doesn't do anything). The only way to eject the DVD drive in OSX, that i've found, is from a shell by typing 'drutil eject'.
SO, for now, i'm running with my PATA HD as a master, dvd drive as slave, and sata drive. PATA drive has XP, SATA has OSX. And that means from OSX I have to go to a shell to eject the dvd. "

A later post above asked if Mac Pro users can change the mode in XP, but a couple readers said there's no options but PIO with the current Mac Pro configuration/drivers.
Apple updated BootCamp before the Mac Pro was released and hopefully will update it again for Mac Pro drivers, unless this would also require a firmware change. (Hardware vendors update their drivers over time, sometimes frequently. So worth checking from time to time, especially if you see any issues with the currently installed ones.)
(Update: On 8/15, Apple released a Boot Camp 1.1 Beta update with Mac Pro, iSight support and more.)

" 1.3 (2006-08-13)

Corrected a mistake that caused the altivec test to be turned off on PowerPC machines

Turned off coalesced graphics updates for all platforms on Mac OS 10.4.4 and higher

Switched compiler to GCC 4.0 on PowerPC. This provides some boost to floating point and AltiVec scores, and these have been recalibrated accordingly. This also raises Xbench's system requirements to 10.3.9 or higher.

Revised machine database to include the MacBook, Intel iMac and several other models

Added code to dynamically load machine database on launch from the Xbench website

Added support for temporarily turning off beam sync on Tiger while running graphics tests

Fixed an issue that causes Xbench to fail to launch on Leopard

Built with Xcode 2.4

I've not tried this version yet, but if you use Xbench, you want to run it several times (each after a clean reboot) and avg the results, as in the past at least I've seen scores from run/run vary more than I'd like to see in some areas (especially on drive tests). It would also be nice to have better/more extensive OpenGL tests included. Also if using a new Mac with Tiger, remember that if Spotlight is indexing of the drive, that affects performance/scores. (You can disable it indexing the internal drive by using the Privacy features, although it will still index any connected (FW, USB, etc.) drive. There's also 3rd party utilities to disable it.)

• Boot Camp Beta 1.0.2: Using the Apple Bluetooth Wireless Keyboard
• iDVD 6: Themes pane is blank after upgrading
• iMovie HD 6 requires Quartz Extreme-compatible graphics cards
• iMovie: Tips to improve performance
• iTunes: MIDI files cannot be converted in iTunes 6.0.3 - 6.0.5
• iTunes: Moving your iTunes Music folder
• iWeb: Hit counter may be reset after republishing a site
• Logic becomes unresponsive when connecting to a network location
• Logic: Clicks and pops when playing instruments live
• Mac OS X keyboard shortcuts
• Mac OS X: No audio from certain multimedia content
• OS X reports hard drive capacity in binary math, hard drive manufacturers report capacity in base 10 math
• Mac OS X Server: AppleShare performance tuning for client and server
• Mac OS X Server 10.4.7: How to install if you have no DVD drive
• Mac OS X Server 10.4.x: Identifying the architecture of a NetBoot or NetInstall image
• Mac OS X Server 10.4: Installing on a computer that won't start up from the Installation disc
• Unable to move, unlock, modify, or copy an item in Mac OS X
• Using Mac OS X Server 10.4 with Intel-based Mac OS X systems
• Using Xsan 1.4 with Intel-based Macs
• Startup key combinations for Intel-based Macs
• Mac Pro: Audio may not switch when new devices are connected
• Mac Pro: How to reset the System Management Controller (SMC)
• Using Emulex switches with Apple Fibre Cards and Xserve RAIDs
• Using QLogic switches with Apple Fibre Channel Cards
• Xsan: Compatibility of SAN clients with Xsan and StorNext controllers

• 64-bit Leopard knocks spots off Vista
• 17-Inch MacBook Pro Transceiver Doubles Wireless Performance (Quickertek)
• Combustion 4.0.4 Updater (Univ. Binary)
• RAID Monitor 1.0.3
• OmniWeb 5.5b3
• GL Golf 1.9
• Sweet16 1.7 - Apple IIgs emulator
• X-Plane 8.5b7
• FWdepot new products (FW and SATA)
• Top Secret Leopard Features Unleashed
• Apple Notebook Power Adapters: Dangerous by Design?
• Cyberduck 2.6.1
• Logitech Unveils VoIP Products
• First Blu-ray disc drive won't play Blu-ray movies
• World of Warcraft: The Burning Crusade preview
• Create Your Own Xbox Game
• Interview with ATI CEO Dave Orton
• 802.11n pushed further into the future