If the category page of your Magento store is loading really slow, the configurable swatches might be the problem. Override /app/code/core/Mage/ConfigurableSwatches/Helper/Mediafallback.php and move

// normalize to all lower case before we start using them
$optionLabels = array_map(function ($value) {
 return array_map('Mage_ConfigurableSwatches_Helper_Data::normalizeKey', $value);
}, $optionLabels);

up to before the foreach loop. This will help increasing the speed of your category page if Magento configurable swatches were causing the problem.