Re: questions about DVFS in saving energy
Xen handles the AMD HE CPUs just fine here. What sort of breakage are you experiencing? William ------Original Message------ From: Tomas L. Byrnes To: Kai Chen To: nanog@merit.edu Subject: RE: questions about DVFS in saving energy Sent: May 13, 2009 2:31 PM -----Original Message----- From: Kai Chen [mailto:kch670@eecs.northwestern.edu] Sent: Wednesday, May 13, 2009 12:25 PM To: nanog@merit.edu Subject: questions about DVFS in saving energy Hi, could anyone here have some idea of the following questions about Dynamic Voltage/Frequency Scaling techniques used for energy efficiency, or please give a pointer that I can trace, 1) how many servers in the market support this technique? 2) how many voltages/frequencies can the servers support? 3) What's the transition time and cost (power) between these voltages/frequencies? Thanks, -Kai ________________________________________________________________________ ____________________________________ My experience with the AMD HE CPUs has been that the scaling breaks Win2K3, and any virtualized environments. -- William Pitcock SystemInPlace - Simple Hosting Solutions 1-866-519-6149
Top-post due to prior: VMWare Server 1.x/ Win2K3 server, standalone and as host for above. VMWare ESXi: Win2K3 and Win2K systems trash volumes. Basically the CPU scaling on the host makes the guest OS fall apart.
-----Original Message----- From: William Pitcock [mailto:nenolod@systeminplace.net] Sent: Wednesday, May 13, 2009 3:20 PM To: Tomas L. Byrnes; Kai Chen; nanog@merit.edu Subject: Re: questions about DVFS in saving energy
Xen handles the AMD HE CPUs just fine here. What sort of breakage are you experiencing?
William ------Original Message------ From: Tomas L. Byrnes To: Kai Chen To: nanog@merit.edu Subject: RE: questions about DVFS in saving energy Sent: May 13, 2009 2:31 PM
-----Original Message----- From: Kai Chen [mailto:kch670@eecs.northwestern.edu] Sent: Wednesday, May 13, 2009 12:25 PM To: nanog@merit.edu Subject: questions about DVFS in saving energy
Hi, could anyone here have some idea of the following questions about Dynamic Voltage/Frequency Scaling techniques used for energy efficiency, or please give a pointer that I can trace, 1) how many servers in the market support this technique? 2) how many voltages/frequencies can the servers support? 3) What's the transition time and cost (power) between these voltages/frequencies?
Thanks, -Kai _______________________________________________________________________ _ ____________________________________
My experience with the AMD HE CPUs has been that the scaling breaks Win2K3, and any virtualized environments.
-- William Pitcock SystemInPlace - Simple Hosting Solutions 1-866-519-6149
Tomas L. Byrnes wrote:
Basically the CPU scaling on the host makes the guest OS fall apart.
Apologies for the general noise (and even more apologies for stepping outside of the nanog scope), but if it's timing related issues does /usepmtimer not resolve this issue for the VMs? It certainly does on other virtualisation solutions.
Apologies for skirting close, but I think power consumption and heat dissipation are pretty big operator costs, and anything we can do to reduce those are beneficial to the bottom line; never mind the environment. More below:
-----Original Message----- From: Karl Southern [mailto:karl@theangryangel.co.uk] Sent: Thursday, May 14, 2009 1:10 AM To: Tomas L. Byrnes Cc: nanog@merit.edu Subject: Re: questions about DVFS in saving energy
Tomas L. Byrnes wrote:
Basically the CPU scaling on the host makes the guest OS fall apart.
Apologies for the general noise (and even more apologies for stepping outside of the nanog scope), but if it's timing related issues does /usepmtimer not resolve this issue for the VMs? It certainly does on other virtualisation solutions.
[TLB:] We tried all the solutions we could Google, including /usepmtimer. A potential 50% reduction in power per system (which is what we were measuring in the tests) would be significant. Unfortunately, it was not stable. It appears to be a Win2K3 issue, although Red Hat Enterprise ran at the declock speed all the time, even under heavy loads (it didn't crash and corrupt volumes like Win2K3, however).
participants (3)
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Karl Southern -
Tomas L. Byrnes -
William Pitcock