Cloud admin on 26 Jan 2009 03:18 pm
Amazon EC2 Instances and cpuinfo
Amazon EC2 provides 5 different instance types and publishes compute capacity as EC2 Compute Unit. But what do they really mean as actual cpu’s reported to the operating system?
Its quite easy to find out. /proc/cpuinfo provides information about CPU and their speed. In the table below I have attached the output of more /proc/cpuinfo for each instance type and the actual proc report on cpuinfo so you can see how tthe OS treats them from a physical CPU standpoint.
| Instance type | Amazon compute units and physical cpu | cpuinfo |
|---|---|---|
| Small Instance | 1 EC2 Compute Unit (1 virtual core with 1 EC2 Compute Unit) 1 physical core @2.6 GHz | small cpuinfo |
| Large Instance | 4 EC2 Compute Units (2 virtual cores with 2 EC2 Compute Units each) 2 physical cores @ 2.0 GHz | large cpuinfo |
| Extra Large Instance | 8 EC2 Compute Units (4 virtual cores with 2 EC2 Compute Units each) 4 phyiscal cores @ 2.6 GHz | extra-large cpuinfo |
| High-CPU Medium Instance | 5 EC2 Compute Units (2 virtual cores with 2.5 EC2 Compute Units each) 2 physical cores @ 2.4GHz | high-cpu-medium cpuinfo |
| High-CPU Extra Large Instance | 20 EC2 Compute Units (8 virtual cores with 2.5 EC2 Compute Units each) 8 physical cores @ 2.4 GHz | high-cpu-extra-large cpuinfo |
on 17 Feb 2010 at 4:22 am # Arpit Patel
Hi
The information is very useful. I would also like to get cpuinfo of the “High Double memory extra large” and “High quadruple memory extra large” instance which are newly instance types introdused by the AWS. Please help me to get this.
Thanks
Arpit
on 29 Mar 2010 at 3:51 am # shreevathsa
Hi,
The informes is very helpful.
thanks
on 11 Nov 2010 at 3:52 pm # shiv
This is completely wrong. What you are providing is the info of the physical core. A small instance get assigned only a virtual core of that physical core.
on 21 Sep 2011 at 12:08 pm # Comparing cloud providers’ pricing models to EC2 … “The devil is in the details”
[...] Developers have noted in blogs which chipsets their servers are using and also noted that they may have different chipsets using different speeds when comparing two servers of the same category. Some of these are older generation hardware that do not support high-speed memory or virtualization. (http://www.cloudiquity.com/2009/01/amazon-ec2-instances-and-cpuinfo/) [...]
on 30 Nov 2011 at 12:48 am # George Ludwig
This is interesting, however I must wonder how relevant the output of /proc/cpuinfo is. For example, let’s say it tells us the actual info on the CPU we are running on. But it doesn’t tell us if we are sharing that physical CPU with anyone.
If Amazon believes they can deliver 2 Compute Units on a single core, and you are only paying for a single Compute Unit, do you really think you have exclusive access to that CPU?
The only real way to tell is to run some comparative benchmarks.
on 30 Nov 2011 at 9:40 am # admin
Of course the most reliable way is to measure the performance of your application or run a benchmark that mimics closest your applications workload on the given hardware. This information is relevant e.g when tuning a multi-threaded application but no more than that.
on 30 Nov 2011 at 9:49 am # admin
we are providing information what the virtual instance operating system reports
on 02 Feb 2012 at 7:38 am # [转载]What are Amazon EC2 Compute Units? « Feisky
[...] Have a look at this post from another blog I contribute to : http://www.cloudiquity.com/2009/01/amazon-ec2-instances-and-cpuinfo/. [...]
on 07 Jun 2012 at 10:22 pm # Andrew Coad
So, from the above, it looks like an Amazon EC2 “virtual core” maps to a physical processor (or, more accurately, has a physical processor underlying it) and an ECU maps to a slice of a physical core. The % of a physical core that is allocated to an ECU depends on the speed of the processor. An ECU is equivalent to a 1.0 – 1.2GHZ Opteron; all of the above processors are dual-core CPU’s running in the range of 2.0-2.6GHz so I’m guessing that on ECU is roughly 50% of a single core. Small, Large and Extra Large instances seem to support this breakdown but the high CPU instances which have 2.5 ECU’s confuses things…