Windows 7: Smaller Footprint?
Writing for his ZDNet blog yesterday, Ed Bott’s research on Windows 7 and Vista memory footprints provides some evidence that Windows 7 may perform better in smaller-RAM and 64-bit installations. See his How well does Windows 7 handle 512MB?
Bott’s tests, which were based on comparisons of 512MB-constrained virtual machines, showed that 64-bit Windows 7 Beta 1 (Ultimate) uses both less memory (according to Microsoft’s Task Manager) and less disk storage than Windows Vista Ultimate. He lists the numbers in a chart. He also compared with XP, and not surprisingly, XP uses both less memory and disk storage than either of Microsoft’s newer OSes. The specific memory data points: XP used 150MB, Vista used 299MB, and Win 7 used 216MB. (See Bott’s story for additional details.)
He also compared Vista and Win 7 in VMs limited to 1GB of RAM, and concluded:
“With the extra RAM available, the delta between the Windows 7 and Vista VMs narrowed dramatically, although the 64-bit edition of Windows 7 still used less RAM than Vista. On the Vista system,. this upgrade made a noticeable difference, whereas the Windows 7 system performed about the same.”
My tests of Windows 7 as compared to Vista have been carried out on a machine with 2GB of RAM and a virtual machine configured to 768MB of RAM. I also have not done any formal comparison of performance, which I always leave to gold code.
Bott mentioned that in 2007, he tested Vista with a circa-2002 P4 512MB RAM machine. (I tested it with three different over-the-hill machines in late 2006 and found that video was the biggest hurdle, although RAM was a close second.) I hope he re-runs that test; he somewhat joking says he might. I might do the same, although I no longer have any machines with less than 1.5GB.
The reason I bring up testing with actual 512MB RAM hardware is that I’ve found that virtualized installations of Windows don’t need as much memory as hardware-based installations. That’s the one quibble I have with Bott’s tests. Even so, it’s hard to argue with the numbers in his results. They’re interesting and instructive.
I plan to test Windows 7 on a 64-bit Vista-level machine (as soon as I acquire one). It’s possible that I will see more performance improvement there.
February 9th, 2009 at 12:25 AM
Scot,
Why the difference in ram needed for virtual vs. real copies of Windows? In my case, due to both the throw-away nature of VMs and the checkpoint features in the VM software, I turn off system restore and the recycle bin but that wouldn’t explain needing less ram. I don’t think so at least.
Michael
February 9th, 2009 at 9:47 AM
Curious, Michael: Have you noticed the same thing? I haven’t given the reason for it much thought. It’s worth doing a little research on — I’ll talk to some of my contacts at VMware and Parallels.