Let me refine this question. - Two users. Similar workload. A real processor with multiple CPUs. The underlying CP has no resource constraints. CP SHARE the same for both users. The only "difference" is user A has one virtual processor and user B has two virtual processors.
I'm not really trying to solve a problem by asking this question. Just trying to understand how CP tries to give everyone "their share". I think we all expect that two users, over time, doing the same work, with the same virtual machine settings, get about the same resources from CP. I'm asking, does giving a user an extra virtual CPU imply that that user is going to get more CPU cycles, merely because of the second virtual CPU? I see Marty thinks the answer is no. That's my feeling too. Did this change at z/VM vs. VM/ESA? Or was it always this way? -----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: [email protected] 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?
