Hey Scully,
There may be a lot of confusion, but there's only one correct answer: "It
depends." :-) Seriously, the SHARE value in the directory (or set by
command) is a function of the virtual machine, not the virtual processor. A
four way with a SHARE of Relative 100 gets a relative 25 assigned to each
vCPU. Thus, adding vCPUs without increasing the SHARE value will only
dilute the "processing power" of the user.
Any benefit of adding vCPUs -- as opposed to just increasing SHARE value
-- occurs only if your existing vCPU is max'ing out a real CPU.
Of course, adding vCPUs and increasing SHARE will only be effective if
the user can actually take advantage of more than one processor
simultaneously (i.e., not CMS).
Marty
____________________
Martin Zimelis
Principal
maz/Consultancy
> -----Original Message-----
> From: The IBM z/VM Operating System
> [mailto:[EMAIL PROTECTED] On Behalf Of Scully, William P
> Sent: Tuesday, September 26, 2006 3:00 PM
> To: IBMVM@LISTSERV.UARK.EDU
> Subject: MIPS vs. Virtual CPUs
>
> All things being equal, does giving a user a second (or third) virtual
> CPU give them "more MIPS", over time, than a user with a
> single virtual
> CPU? When I speak with experienced VMers there seems to be a distinct
> difference in opinion on this. Some think, yes, give me a second
> virtual CPU and I'll get "twice the work done." Others think you'll
> only get twice the CPU if your CP SHARE is "twice as large as
> the other
> guy."
>
> What's the REAL answer?
>
