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#### 1.4.1 Checking New Groups

Gnus normally determines whether a group is new or not by comparing the list of groups from the active file(s) with the lists of subscribed and dead groups. This isn't a particularly fast method. If `gnus-check-new-newsgroups` is `ask-server`, Gnus will ask the server for new groups since the last time. This is both faster and cheaper. This also means that you can get rid of the list of killed groups altogether, so you may set `gnus-save-killed-list` to `nil`, which will save time both at startup, at exit, and all over. Saves disk space, too. Why isn't this the default, then? Unfortunately, not all servers support this command.

I bet I know what you're thinking now: How do I find out whether my server supports `ask-server`? No? Good, because I don't have a fail-safe answer. I would suggest just setting this variable to `ask-server` and see whether any new groups appear within the next few days. If any do, then it works. If none do, then it doesn't work. I could write a function to make Gnus guess whether the server supports `ask-server`, but it would just be a guess. So I won't. You could `telnet` to the server and say `HELP` and see whether it lists ‘`NEWGROUPS`’ among the commands it understands. If it does, then it might work. (But there are servers that lists ‘`NEWGROUPS`’ without supporting the function properly.)

This variable can also be a list of select methods. If so, Gnus will issue an `ask-server` command to each of the select methods, and subscribe them (or not) using the normal methods. This might be handy if you are monitoring a few servers for new groups. A side effect is that startup will take much longer, so you can meditate while waiting. Use the mantra “dingnusdingnusdingnus” to achieve permanent bliss.