Anti-DDoS HTTP Throttling in Older Versions of Chrome
Chrome 12 through Chrome 19 had anti-DDoS HTTP throttling not only for requests originating from extensions, but for normal web page requests as well. To disable throttling in versions of Chrome up to 20.0.1115.2: Type chrome://net-internals/#httpThrottling into the address bar and uncheck the checkbox labeled "Throttle HTTP requests if the server has been overloaded or encountered an error."