I am at the point in installing Ubuntu 10.04 in VMWare Workstation 8.0 where the following dialog box appears:

enter image description here

My physical PC has a AMD 970 B.E. quad-core processor. I've never installed an OS in VMWare before, and I'd rather not do this twice. I assume I should have "1" for "number of processors," but as for "number of cores per processor," I'm not sure.

Can someone offer some advice?

Edit: I did find a very similar thread here, but no clear answer was given. I understand that it is ultimately up to the user, but I have no baseline to go by here, never having installed an O.S. on VMWare.

2 Answers 2


Well what you're doing here is basically limiting the nunber of cores available to VMware.

If you want to be sure that your host OS will remain responsive, you can set the number to be lower than number of your processor cores. This way VMware will not use some of the cores.

If you want maximum performance for virtualized system, you should provide it as much cores as possible.

  • Thinking rationally about this, say I used "1 processor, 4 cores." This could potentially detract from the performance of the host OS. However, would I be using both the host and guest OS's simultaneously? Likely never. I'd obviously be working in one or the other. Once I am done using VMWare, I could terminate it and return to the host OS. Is my thinking wrong here?
    – user76275
    Oct 18, 2011 at 6:55
  • 1
    @H3br3wHamm3r81 It's OK in my opinion. Today's virtual machines are capable enough so that if something pops up in the host OS you shouldn't have any problems due to virtual machine load.
    – AndrejaKo
    Oct 18, 2011 at 7:02
  • @H3br3wHamm3r81 Actually there's one additional reason why you may want to limit the number. If you're planning on using some very old applications, it could be that some of them may have problems with more than one thread executing at a time. I never had such a problem, but I heard people report it. Do note that it has nothing to do with vitualization, but with having more than one processor or core in the system.
    – AndrejaKo
    Oct 18, 2011 at 7:06

As long as the total does not exceed the number of "cores" available to the host operating system, it does not really matter. VMWare will do all the "magic" for you! However, I would recommend you go for one processor with additional cores.

As far as I know, this option is here due to limits in some operating systems/configurations. For example, Windows Client supports a maximum of 2 processors, but (I believe) unlimited cores. Meaning if you select over 2 processors, there may be some limitations... Selecting 1 processor with 4 cores, or 2 processors with 2 cores has very little difference (if any).

FYI, with regards to licensing, I can't find concrete proof, but, I know that all OEM licenses used to ship with the writing "1-2CPU only", upon enquiring, I was told this is a hard CPU limit.

  • So, you think it would be okay to do 1 proc/ 4 cores?
    – user76275
    Oct 18, 2011 at 6:59
  • @H3br3wHamm3r81 Yep! Oct 18, 2011 at 7:05
  • Thank you both for your comments. I had to accept one, so even though both were equally helpful and acceptable, I based the acceptance on who responded first. But, I definitely appreciate both people for taking the time to answer.
    – user76275
    Oct 24, 2011 at 23:40

You must log in to answer this question.