Fast and Secured: Performance Impact of SSLにWindows+IIS+ASP.NETにおけるSSLのパフォーマンスインパクトを評価した結果が載せられている。


Test Result

Throughput (# of Transactions in 10-minutes)
Baseline: 1401 or 2.3-per second
SSL: 1317 or 2.2-per second
Delta: 5%

ASP.NET Execution Time
Baseline: < 500-mseconds
SSL: < 500-mseconds
Delta: N/A

IIS CPU Utilization
Baseline: 6%
SSL: 30%
Delta: 24%

IIS Memory Utilization
Baseline: 4-mb in 10-minutes
SSL: 19-mb in 10-minutes
Delta: 15-mb

IIS Server Disk Utilization (Bytes/second)
Baseline: 16,935
SSL: 19,937
Delta: ~3,000-bytes/sec

IIS Server Network Utilization (Bytes Total/Second
Baseline: < 500-mseconds
SSL: < 500-mseconds
Delta: N/A


Another major impact of applying SSL is to caching. SSL protects sensitive data. As a rule of thumb, caching should be turned off for sensitive data. The Knowledge Base article KB234067 discusses how to turn off caching.

Further, some web pages are developed in HTTP and there are many objects within the web page such as jpg and js files. The developer relies on caching to make the web page fast. Yet, they forget when SSL is turned on for production, these files are not cached anymore and performance degrades as a result. The solution is to keep the web page simple to begin with.