Domino gets a bum rap from many people as a bandwidth hog and a memory hog. The truth as has been proven many times over is far from these 2 erroneous conclusions.
Based on the client I have been at this week and some other past customers, here is a list of what to look for before one blames Domino for any performance issues.
Note: I will not describe notes.ini tweaks or any other server setting type things, the best practices from Lotusphere on Server Performance is a good place to start as are some redbooks and wikis.
Let's start simple.
1) Hardware - Your server is so old, the nameplate fell off when the original admin retired. Or the dust accumulated in it's case/fan is thicker than mashed potatoes. Seriously, this has zero to do with Domino.
Now having said that, Domino runs perfectly fine with whatever you give it to work on, but if you need more than a small office on it, this could be your problem in a nutshell. Add some RAM or another drive as a new temp/swap file or for transaction logging. A $100-300 dollar investment that will pay you back well. Or just buy a new server.
2) Switch/Router/Hub - Raise your hand if you still have one running someplace that ONLY does 10MB. Raise both hands if you have Token Ring running to your server still.
Yes this is an issue. No, you don't have to update these every year but do a check of speed and transfer. If you are getting, as we saw recently 33kb/sec you REALLY need a new box. Swapping from switch A to B raised transfer rates to 11MB/sec. Better but still slow. So check it, think about it, spend the money on some new ones. Rule of thumb is about $10 dollars per port. Get 1GB switches.
3) Cables - Yes, your cables may be from the Clinton years and NOT Cat 5E or CAT6 so check them as well and invest in a box of cable and cut some new ones. Nothing worse than using cable than forces you to be trapped at 10MB.
4) Firewall - What does this have to do with anything? Have external users or VPN access? Forget the fact it probably doesn't support Windows 7 but how have you survived on a device which is probably out of support/maintenance and maxes out at 100MB and you aren't even plugged into that port but the 10MB port. Again, your network is your lifeline, save it and save yourself and your employees.
5) Backup solution - Do what you need but keep in mind that if your backup is taking 6-10 hours you have more issues on your hands. Backup is easier and cheaper now and even replicating all your dbs to a second server is a better idea than a massive backup window because of old hardware. Why does this affect Domino? Because it interferes with users working and more importantly the server's processes that should run every night.
6) Disk Space - Already alluded to but a lack of disk space will cause full text index failures and potentially hold up server reactions for users attempting to open a mail file or an application which requires on the fly indexing(hopefully you are doing this correctly) or some similar type action. Like an agent on opening. Drives are cheaper than a whole new server, but you know once you start using an external array of drives or a SAN you really should get a new server.
All is NOT lost, all of this equipment can be reused as demo/test equipment or for stage/dev type functions. Donate it to a non-profit or school in a part of town that really needs anything they can get their hands on. Many public school systems are in budget constraints and while some have up to date technology, many do not.
Lastly, give it to your kids or design a network that runs on purpose slowly for younger grade children to learn about how a network works. Sure they want it fast, but now you can walk them through a full loop and the processing will still be running so they can see it all happen not just click here and get it.
Oh and get that Domino server upgraded to 851fp1 or whatever R8 you want because THAT is within your scope to fix and it is easy too.