For instance, with a level of IIS compression set to 9, the web browsing is significantly faster. However, I also have a Web Services application on the box, which transfers significant amounts of data (e.g. 3MB payload is typical), it actually takes 20-30% longer for the data to get to the client, because the CPU on the server takes a while to compress it.
Is there a rule of thumb for the level of IIS compression vs amount of data transfered?
Anecdotal experience is welcome as well.
Doubtful, because there are so many variables:
I expect the connection is fairly speedy in your use case? Compressing 3MB shouldn't take all that long after all.
Ok, I ran some benchmarks and no matter how you slice it, turning off compression results in faster performance for my use case. Here are the result for a web service call that returns 3.2 megabytes of data (mostly list of things deserialized into byte arrays)
Compression Bandwidth Time
Level (KB) (seconds)
9 1,174 4.2
8 1,174 2.2
7 1,172 1.625
6 1,174 1.5
5 1,181 1.39
4 1,213 1.344
3 1,441 1.375
2 1,490 1.344
1 1,548 1.312
0 1,554 1.312
No 3,226 1.266
Compression
The CPU is pretty pegged at level 9 for the duration of the web service call, not so bad at level 8 and anything beneath that is in single digits utilization.