I have to wonder if my recent blog post, "The MSRs of EC2", on September 15th has prompted this discovery: http://www.brendangregg.com/blog/2014-09-15/the-msrs-

I have to wonder if my recent blog post, "The MSRs of EC2", on September 15th has prompted this discovery: http://www.brendangregg.com/blog/2014-09-15/the-msrs-of-ec2.html http://www.brendangregg.com/blog/2014-09-15/the-msrs-of-ec2.... . When I posted that, I could find no examples of MSR usage in EC2 or Xen. I haven't checked after the reboot, but I hope the MSRs I'm using can still be accessed: IA32_MPERF and IA32_APERF (to calculate real CPU MHz); IA32_THERM_STATUS and MSR_TEMPERATURE_TARGET (to calculate CPU temperatures); and MSR_TURBO_RATIO_LIMIT and MSR_TURBO_RATIO_LIMIT1 (to see turbo ratios). I use them in the showboost, cputemp, and cpuhot MSR-based tools: https://github.com/brendangregg/msr-cloud-tools https://github.com/brendangregg/msr-cloud-tools