General wisdom has it that unless you have an ISP with a very slow DNS server, that it may take longer for Windows to locate the DNS entry for a host locally than it does to use an internet-based DNS server, if you have a very large hosts file. There is no definite rule on this, but you should experiment by timing the length of time it takes to locate (and begin to load) a few sites using the hosts file and how long it takes if you disable the DNS accelerator (and therefore the hosts file) and locate a few other sites using the internet-based DNS server. You may want to limit the size of your Hosts file to a more reasonable list of sites that you visit most often.