DynamoDB is silly expensive

comparison.md

Intel 320 vs DynamoDB

As a note, if you find errors with the math below, please let me know.

This cost comparison only compares cost per I/O operation. It does not discuss storage or transit costs.

Intel 320

• Intel 320 series SSD, 300GB specs: http://www.intel.com/content/www/us/en/solid-state-drives/ssd-320-specification.html

At 4K, IOPS rates are advertised as:

• read: 39500/sec
• write: 23000/sec

Cost of an Intel 320 300GB drive: About $500

DynamoDB

Comparing the same IOPS advertised by Intel 320 300GB, but with DynamoDB pricing - Pricing specifics are here: http://aws.amazon.com/dynamodb/#pricing

• Read units: 39500 * 4 = 158000

• Read cost: (158000 / 50) * 0.01 (per hour) = $31.60/hour

• Monthly read cost: $31.60/hour * 24 hours * 30 days = $22752.00/month (every 30 days)

• Write units: 23000 * 4 = 92000

• Write cost: (92000 / 10) * 0.01 (per hour) = $92/hour

• Monthly write cost: $92/hour * 24 hours * 30 days = $66240/month (every 30 days)

Analysis

Amortizing the cost of hardware over 3 years is fairly common, so I will use that as a frame.

This puts the cost of the Intel SSD at $500 per 3 years.

The same IOPS performance on DynamoDB over 3 years (forgetting leap years) will cost:

• dynamodb total: $3,248,208 per 3 years
• intel total; $500 per 3 years.

separating reads and writes:

• dynamodb read cost: $31.60 * 24 * 365 * 3 = $830448
• dynamodb write cost: $92 * 24 * 365 * 3 = $2417760