Poor Dreamhost performance

I received the infamous “too many server resources” email from Dreamhost recently. I decided to get active and profile my installation using the PEAR Benchmark class. What I found was surprising to me.

I’m using WP-Cache 2.0.17 and a fair quantity of plugins. Serving dynamic pages takes more than a second. Serving cached pages takes on average 0.5 to 0.7 seconds. With the Dreamhost restriction for shared hosts of 30 processor minutes a day, that means that after serving roughyl 3,000 cached pages, I’m past my allocation. That’s not counting any uncached pages of which there are sure to be plenty.

Upon benchmarking the caching, the entire time — well, 90-95% of it — is spent in readfile(). So that single PHP call is taking over half a second to read a simple HTML file and poop it out over the network.

Does this seem just utterly out of line? This basically means that anything over even a small readership — like when I got linked by Gizmodo which was when I got my warning email — causes me to go over my allocation.

I’ve got a support email in to them but frankly hold no hope. Just looking for confirmation that I’m not going totally crazy thinking that caching should be a whole lot better performing than that.