The chart represents the relationships between: instance type (using the API name), instance family, CPU speed (approximation, see below), memory size, storage size, storage performance and price (for one region, see below). You can choose axis variables and track the evolution of prices of each type of instance using the interactive chart.
CPU speed has been calculated multiplying each virtual machine ECUs by 1.2 to obtain a GHz approximation. This has been done following the AWS definition: "One EC2 Compute Unit (ECU) provides the equivalent CPU capacity of a 1.0-1.2 GHz 2007 Opteron or 2007 Xeon processor."
Price information belongs to the us-east-1 region instances (Northern Virginia). I´ve chosen this region because is the oldest one and implements all types of instances. The operating system of reference is linux, to avoid taking account of the added licensing costs.
Some interesting things can be seen using the graphic:
- When using CPU in horizontal axis and memory size in the vertical axis, both in logarithmic scales (like in the picture) an almost constant scalation factor of CPU and memory appears between instance steps.
- Because of this the instances bubbles appear to reside in two lines, almost equally separated between them. As it is expected, one line is memory intensive (m1, m2 families) and the other line is CPU intensive (c1, cc1, cc2 families)
- Althoug t1.micro seems to belong to the CPU intensive line, actually the 2 ECUs are allocated only for usage in short spikes.
- Storage size and I/O perfomance can be shown in the same graph using bubble color and sizes, with CPU and memory size in the axis. This can give a more complete view of the performance of all instances in the AWS portfolio.
- Trend line graph (topmost right icon) can be used to show the lowering prices trending in the latest years for each type of instance.
- us-west-1 and sa-east-1 pricings before AWS lowered prices in March 2012
- cc1.4xlarge, cc2.8xlarge and cg1.4xlarge windows instances prices before AWS lowered prices in March 2012
- m2 family instances introduction prices, before AWS lowered prices in November 2009