Now I found that the world is round.
Customize these thumbnail URLs to a pretty one with URL rewriting. Then thumbnails can also be cached by Cloudflare or other CDNs, which could reduce a lot of requests from the timthumb.php file.
In the past 2 years I was told many times by friends who lived outside mainland...
Cloudflare is the best free CDN provider as I know, and I’ve been enjoying its fantastic...