I have a mid-2010 Mac Mini with 2.4 Ghz Intel Core 2 Duo processor. I did not use the mac mini for several years, but dusted it off a few months ago and now my husband uses it every day. I upgraded the OS to Lion and then to Sierra. Now the Mac mini is pretty slow and takes a long time to startup.
Some of it will just be dealing with a newer, more complex, more featured loaded, and thus more bloated version of the Mac OS.
Beyond that, as I understand it, newer versions of the Mac OS are optimized to take advantage of an SSD. As a result, as I understand it, they are not quite as optimized for use on a traditional hard drive.
Is there anything I can do to speed it up?
You certainly could upgrade the drive from an traditional hard drive to an SSD. It is a bit on the more complex side of Mac upgrades but still do able. If you want to see what would be involved to do it yourself, there here is a guide you can look at to see if you think you would be up to it:
The other possible upgrade would be to upgrade the RAM. You did not mention how much RAM you have now, so this may or may not help much. That model can technically support up to 16 GB of RAM even though Apple listed its max at 8 GB...if running Mac OS 10.7.5 or higher, the firmware is fully updated, and you get the right modules. You can read more here: http://blog.macsales.com/16302-some-2010-mac-owners-can-get-more-ram-than-they-thought
If you thought you wanted to upgrade the RAM, then here is a guide showing what is involved:
Is it advisable to upgrade a Mac mini? Apple advised that they do not upgrade but third party vendors may have an upgrade.
Any suggestions would be helpful.
If it advisable to upgrade? That will really depend on you...i.e. how you use the Mac/what you use the Mac for, how much you might want to spend, etc. If the Mac still does what you want/need it to do and don't want to go buy a new Mac for whatever reason (i.e. mainly because they are expensive), then upgrading might be the best option. After all, you could go to 16 GB for about $127
and a 120 GB SDD for about $70
(or less with other options). If 120 GB is too small, then you are talking about $100 for 240 GB or about $200 for 480 GB. This all assumes you do it all yourself. It would likely be more expensive if you paid someone to do the upgrades. So, if you can survive with just 120 GB SSD, then you could upgrade for about $200 (or less if you find a cheaper SSD option [I like the OWC SSDs because they are designed specifically for use with Macs and the Mac OS] or if you decided not to do the RAM upgrade or just upgrade to 8 GB of RAM). That is significantly cheaper (i.e. $300 or more savings) than the cheapest new Mac Mini.
Of course, with the a new Mac Mini, you will also get a faster, newer processor and you will have longer support for it with newer Mac OS versions. You current Mini can run the latest (Sierra), but it might be able to run future versions. This will means you will get security updates for it for at least the next two years, but beyond that, it is not known.
Apple will definitely not be an option as they no longer support that model (just like they no longer support my 2009 17" MBP).