Mac Mini's performance randomly takes a nosedive, requiring a restart

[iRockMan1]

I don't know when it started, but my mid 2011 Mac Mini's performance becomes horrible at seemingly random times. It becomes so maddeningly slow that the computer is practically unusable during these periods. It's fixed after restarting, but it's so slow that I can't restart normally because when I try to do so, it tells me that the computer couldn't restart because __ application wouldn't close. And closing applications takes so long during these periods that I can't be expected to close them all; when I close one, the whole computer freezes (save for the mouse cursor) and I have to wait until it's fully closed before I can do anything else. So I just hit the power button and the computer runs fine (at least as fine as you would expect this Mac Mini to) after it powers back on.

The most recent occurrence came after playing and closing Minecraft. The fans were going pretty hard, but that doesn't necessarily always precede these performance lulls. And this can happen when using any application.

I'm not much of a hardware guy, so I was wondering if anyone here had any insight as to what the problem could be.

Specs:
2.3 GHz Intel Core i5
8 GB 1333 MHz DDR3 RAM (http://www.amazon.com/dp/B002YUF8ZG/ref=pe_175190_21431760_cs_sce_dp_1)
Intel HD Graphics 3000
Mac OS 10.8.3

 

[Fishrrman]

Are you running out of memory?
Are you running out of hard drive space?
Do you have Time Machine turned on?

 

[Omnius]

I had this happen once on my base model 5,1 mini. It was really quite weird because I had a decent amount of free ram and did not observe any page outs. The machine wasn't overheated and was actually quite quiet and cool.

It's never happened on my 5,2 mini and I use that far more. Perhaps, it's possible there is a defect in the model with the HD3000?

 

[SoCalReviews]

It sounds like it could be a RAM problem or RAM incompatibility issue because rebooting the machine clears the problem.

I also have the 2011 i5 2.3Ghz base model and while I don't push my Mac Mini very hard with CPU intensive programs I have never had any slow down problems using Parallels 8 virtual machine software with up to four VMs (Windows XP Pro SP3, Windows 8 Pro, Ubuntu Linux, Chrome OS) at one time. I am using 16GB (2 x 8GB) of Crucial memory installed. If possible see if the slowdown problem still happens with a different compatible dual RAM kit.

 

[macizcool]

OP, I just had the same problem with my 2010 Mac mini. It would become so unresponsive that the only option (besides waiting an eternity for the beach balls to go away) was to hold down the power key and force it to shut down.

I just wiped my hard drive and reinstalled Mountain Lion to see if that clears things up. I hope it's not bad memory. How would we know if the RAM is bad?

 

[comatory]

i would try these steps:
1. look at activity monitor when these slowdowns happen - there might a weird process bogging it down
2. create a new user account, log into it after restart and see if it happens in new user account
3. do a clean install of your OS (make sure you make backup of everything). start installing your applications one by one to see if there is a specific app causing this behaviour.
4. try doing Apple Hardware Test and checking the memory
5. remove one memory module and swap them to see if there is any bad RAM
6. if your mini is in warranty, return it to Apple for them to fix it
7. open your mini (read iFixit first!) and check if the cable leading to your hard drive isnt loose. you can try reconnecting it to make sure.

if nothing helps, you would have to dive in more to see if it is hardware failure. so far it seems that software might be causing it, if its hardware fault its probably RAM or hard drive.