Windows 7: 32-bit or 64-bit under Parallels 6?

Discussion in 'Windows Guest OS Discussion' started by KPOM, Oct 25, 2010.


Which version of Windows 7 Pro should I install?

Poll closed Oct 30, 2010.
  1. 32-bit

    3 vote(s)
  2. 64-bit

    1 vote(s)
  1. I'm upgrading to a new top-of-the-line MacBook Air (4GB RAM, 2.13GHz processor, 256GB SSD) and am debating whether to install the 32-bit or 64-bit version.

    Up to now, I've used Windows 7 32-bit since I had only 2GB on my outgoing Mac. I installed Windows in Boot Camp since there is one application where I need to use Windows XP Mode (which only works in Boot Camp). If I were just using Boot Camp, I'd go with 64-bit, but since I'm also planning to use Parallels, I'm a little less sure.

    I plan to allocate 2GB of RAM to Windows 7 in Parallels. Has anyone used this with the 64-bit Windows 7? If so, how well does it work? The main thing I'd be accessing through Parallels is Quicken. Everything else I use in Windows I'd likely use in Boot Camp.
  2. 64bit Windows 7 works fine in Parallels 5 and 6 from my experience.
  3. Thanks. A similar poll at Macrumors has 64-bit ahead so I'll probably go with that once my new MacBook Air arrives.
  4. Core 2 Duo

    But does the Core 2 Duo in the MB Air support 64 bit at all?
  5. All Core2Duo processors support 64bit processing. It is also a prerequisite for running OSX Snow Leopard
  6. Yes, both 32-bit and 64-bit versions are supported on the new MacBook Airs. Curiously, Vista and XP are not officially supported by Boot Camp. I went with 64-bit and it is great both in Boot Camp and Parallels 6.
  7. Configuration

    What's your Air's configuration and do you have any issues with windows programmes not running in 64 bit?
  8. I have the 13" 2.13GHz model with 4GB of RAM. I allocated Win 7 1.75GB of RAM in Parallels 6. So far I have had no issues with 32-bit Windows programs or with finding 64-bit drivers for my scanner and printer.
  9. And what is the most resource demanding application you have been running under Win 7 in Parallels so far?
  10. I use Quicken for Windows the most often. Probably the most resource-demanding application is Internet Explorer when viewing Flash content, though.
  11. Thanks, I am still a bit worried whether I'll b able to run all my XP 32 bit stuff in a virtual Win 7 64 bit environment. Guess, I'll have to find out myself.
  12. You might try downloading the Windows 7 Upgrade Advisor and running it on your XP setup.

    In general, it isn't applications that are a problem with 64-bit Windows. It is old peripherals with drivers that haven't been updated to 64-bit. Also, 16-bit applications don't run on 64-bit Windows, but very few applications have been written with any 16-bit code in a long time. Some old Win95 apps had some 16-bit code, but for the most part programs written for XP run in 64-bit Windows.
  13. Thanks for the link!

    Have you actually tried both 32-bit and 64-bit with your MacBook Air, and could you compare it?

    I´ll have the same MBA as you pretty soon and still tend to buy the 32-bit...still not convinced as I´ll use Parallels more often than Boot Camp.
  14. I had Windows 7 32-bit on my old MacBook Air and wouldn't have attempted 64-bit on it as it had only 2GB of RAM total. I didn't install 32-bit on my current Air, but went straight to 64-bit. On the whole. it is much faster on my Rev D Air than 32-bit ever was on my Rev B (even though I had the optional SSD on the older Air). It is perfectly fine with the 2GB i give it in Parallels, and the 4GB it gets in Boot Camp. That said, you'd be completely fine running 32-bit, especially in Parallels. 64-bit is of most benefit when you have 4GB of RAM or higher. Since 4GB is the Air's maximum, it is right at the cusp of where 64-bit becomes worthwhile. Note that almost all Windows programs are still 32-bit, so the main benefit of 64-bit is the full access to 4GB of RAM.
  15. And even new software will be compatible with 32 bit for years...
    I actually would like to exploit the full 4GB in boot camp, since I plan to use the boot camp installation of Win7 for demanding software that might not be run smooth enough in Parallels. However, most of the time I'll use Parallels for my day to day stuff in Windows, so 2GB allocated should be fine.

    My worries are that if I install 64 bit it might run smooth in Parallels even with 2GB of allocated RAM, but it will go into swap (accessing the SSD all the time to compensate for lack of RAM) instead, which is not a good thing for the SSD's life expectance (limited read/writes per block).
  16. I'll check to see how often it swaps out on my Parallels setup. I give it 1.75GB of RAM.

    What I don't know is whether the GPU uses Window's RAM allocation or the Mac's allocation when processing the VM's graphics requests (meaning it would take up to 512MB when the VM is running).
  17. Looking forward to seeing the results!
  18. I definitely notice that the page outs (i.e. writes from RAM to the SSD) increase when I run Windows 7 within Parallels. That said, I don't really notice a slowdown of either Window 7 or OS X on basic tasks.
  19. Luckily, the SSD makes swap not much noticeable due to its speed, but the fact that it is needed so often is not very favourable for the flash drive.

    Anyway, did you encounter any problems activating Win 7 in boot camp AND in Parallels? I assume you used the same installation for both. Any guide for installation and activation you can recommend?
  20. I was able to activate it successfully in both Boot Camp and Parallels. Note that in order to do that, you need to activate first in Boot Camp. Then the first time you run the VM in Parallels, install Parallels Tools, and then activate again in Parallels. You might get kicked into the phone activation system the second time around but it is fairly quick.

Share This Page