[FoRK] Anyone know if EC2 takes a while to flex the CPU speed up

Gregory Alan Bolcer greg at bolcer.org
Tue Jul 16 10:29:55 PDT 2013

Run this on both systems.
dd if=/dev/zero of=test bs=64k count=16k conv=fdatasync

Also, I'm guessing it's allocating memory that the VM doesn't have 
immediately accessible so that the cpu gets way ahead of the memory.


On 7/16/2013 9:54 AM, Andy Armstrong wrote:
> On 16 Jul 2013, at 15:51, Gregory Alan Bolcer <greg at bolcer.org> wrote:
>> What type of instance is it?  Is the workload io intensive?
> Seems to be an m1.xlarge.
> And the workload is multiple ffmpeg based h264 encodes (no GPU acceleration) - the step change in workload typically being a switch from a static image to video with a lot of movement. When that happens I see about 30 seconds of thundering herd and then it settles down. Not seeing that behaviour on a physical box.
> Fairly low bitrates (~3Mb/s total) so it's not I/O bound.
> However, running this when it's cold doesn't show any measurable warming up effect:
> $ while sleep 1; do time perl -e 'next for 1..100_000_000'; done
> Shrug.

greg at bolcer.org, http://bolcer.org, c: +1.714.928.5476

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