I have a furniture store that consists entirely of configurable products.
Example 1: Configurable product with about 350 simple products
I am experiencing a very long load time on category pages. Our configurable products have about 350 simple products each. To load a category page (http://www.telescopeoutdoor.com/sling/romanesque) takes average 13 seconds. This can take up to 40-50 seconds.
To load a product page can take up to 50 seconds (http://www.telescopeoutdoor.com/sling/romanesque/romanesque-sling-arm-chair.html)
Example 2: Configurable product with 80 simple products
Load time is significantly better, usually 2-3 seconds.
It seems like there might be a threshold for configurable products where the code starts to choke up. I have tested this one two different dedicated servers. The current server is a 2.3Ghz Quad Core Zeon, 4GB Ram, 3 x 73GB SA-SCSI 10k RAID 5. I have installed php 5, mysql 5 and have installed APC into PHP. APC seemed to help a little bit but not much.
To the Magento team: Have you seen this problem with many simple products? Is this something you are working on? Any ideas for how I could speed this up?
Other than those massive configurable products, everything else is running very fast.