Can Windows Vista run on the Intel-based Macs?

A quick trip to Microsoft's Windows Vista "Get Ready" website provides the hardware requirements for a "Vista Capable" and "Vista Premium Ready" system.

Microsoft states that a "capable" system is one that can run Windows Vista and "deliver core experiences such as innovations in organizing and finding information, security, and reliability" but "run these core experiences at a minimum". Some Mac users may find the idea of running the "core experiences" of security and reliability "at a minimum" a bit amusing.

Nevertheless, Microsoft says a "capable" system must have at least:

• An 800 MHz or faster Intel-compatible processor.
• 512 MB of RAM.
• A graphics processor that is "DirectX 9 capable".

Even the slowest Intel-based Mac, the Mac mini "Core Solo" 1.5, has a 1.5 GHz Intel "Core Solo" processor, 512 MB of RAM installed by default (upgradable to 2 GB), and as noted on the relevant Intel specifications page, the "integrated" Intel GMA950 graphics processor has "DirectX 9 3D hardware acceleration". The MacBook models, the education-only iMac "Core Duo" 1.83 17-Inch (IG), and the iMac "Core 2 Duo" 1.83 17-Inch (IG) have faster processors and the same "integrated" graphics.

The remaining Intel iMac models, the MacBook Pro, and Mac Pro all have faster processors and substantially faster graphics processors. So, all Intel-based Macs are "capable" of running Windows Vista.

However, a system that only meets the very modest "capable" requirements probably will be unable to run the MacOS X "Aqua-esq" Windows Aero user interface.

For "an even better Windows Vista experience" Microsoft recommends a "premium ready" system, which must include at least:

• A 1 GHz or faster Intel-compatible 32-bit (x86) or 64-bit (x64) processor.
• 1 GB of RAM.
• A graphics processor that runs Windows Aero.
• 128 MB of graphics memory.
• 40 GB of hard drive capacity with 15 GB free space.
• A DVD-ROM drive.
• Audio output and internet access capability.

In the default configuration the Mac Pro is fully compatible with Windows Vista. Additionally, some MacBook Pro and Intel iMac models only are prevented from reaching the "premium ready" designation because of Apple's default skimpy installation of 512 MB of RAM. If you did not configure your MacBook Pro or Intel iMac with at least 1 GB of RAM at the time of purchase, you will need to upgrade the RAM in order to reach the recommended requirements to run Windows Vista. Realistically, MacOS X also runs much more smoothly with at least 1 GB of RAM installed.

As configured by default, all MacBook and Mac mini "Core" models (along with the iMac "Core Duo" 1.83 17-Inch (IG), and the iMac "Core 2 Duo" 1.83 17-Inch) fail to reach the 1 GB of RAM requirement and with "Intel GMA950 graphics processor[s] with 64 MB of DDR2 SDRAM shared with main memory" fail to meet the 128 MB of graphics memory requirement as well.

Regardless, in the "Windows Vista Capable and Premium Ready" footnotes, Microsoft acknowledges that Windows Aero requires a "DirectX 9 class graphics processor" that "supports a WDDM driver, pixel shader 2.0 in hardware, and 32 bits per pixel". Intel's website reports that the GMA950 supports those features and is "ready for Microsoft Windows Vista". Microsoft also says that with 64 MB of graphics memory, a computer can run Windows Vista with Aero but will only "support a single monitor less than 1,310,720 pixels", which in more usual terms is a 1280x1040 display.

As the MacBook has a 1280x800 native resolution display, it can run Windows Vista with Aero on the internal display -- but not an external display at the same time -- provided that 1 GB or more RAM is installed. The Mac mini "Core" systems, likewise, can run Windows Vista with Aero on a display no larger than 1280x1040 if at least 1 GB of RAM is installed.

Windows Vista with Aero would not formally be supported on the iMac "Core Duo" 1.83 17-Inch (IG), and the iMac "Core 2 Duo" 1.83 17-Inch, even with 1 GB of RAM installed, as each has a 1440x900 native resolution display. It might run at 1440x900, perhaps sluggishly, but would not be supported officially.

For a video clip of the Windows Aero interface in action on a system using a GMA950 graphics processor, please check out YouTube.

However, it is entirely likely that it will be possible to increase the amount of system RAM that the Intel GMA950 graphics processor "borrows" from main memory with a future firmware upgrade, which would make it possible to run Windows Vista with Aero on larger or additional displays. Although increasing the amount of memory used by the graphics card likely would in turn make it necessary to install RAM in excess of 1 GB to maintain the same level of performance.

Ultimately, with at least 1 GB of RAM installed, nearly all Intel-based Macs will meet the basic "premium ready" requirements and run Windows Vista with Aero, should you choose to do so.

You also may find Hans VB's weblog interesting, as he has documented the process of installing and using Beta 2 of Windows Vista via Boot Camp. The TUAW blog has posted a walkthrough of how to run the beta version of Windows Vista via Parallels Desktop that also may be of interest. Finally, the always excellent MacInTouch has a number of Reader Reports on Vista that are well worth reading.