How to improve unexpectedly poor Craft performance? We have a seasonal website which gets very popular around this time of year. This year we ported it from ExpressionEngine to Craft, for all the obvious reasons. We were very surprised to discover that the Craft version of the site is using considerably more resources than the old EE one. I'm looking for any advice on how to get this load down.

For info; both sites used the same dedicated Virtual Server, a quad core Xeon (minimum 800Mhz, burst to 2Ghz) with 8Gb RAM.

This weekend the Craft site was dealing with around 500 simultaneous visitors but pushing the CPU load to 7. By judicious use of the {% cache %} tags I dropped the queries per page from 200 to 20, and the load dropped to around 4-5.

Once the site is seeing 700 simultaneous visitors the CPU load is going into double digits and rapidly starts to spiral.

We had to switch out to a static scrape of the site. At the peak last year we were dealing with 1000 simultanious visitors and did not need to switch out to a static site.

I should point out that both sites are loading all their assets off Amazon S3, so none of those files are having an impact. This is purely about Craft being able to deal with the number of requests it's getting.

Why might Craft be performing so poorly in comparison, and how can I fix this?
This is a great resource on improving performance as it's a multi-pronged attack:


Native craft caching {% cache %} which you mentioned you have done
CDN and Browser caching
Varnish and other tools, including plugins like Cache Warmer


I concentrated on cache as this is usually where the bottleneck seems to happen in Craft. Apologies if you've addressed all these already!