Installed 6 GB RAM now machine is super slow
2.2 GHz A1226 machine: Last night I installed the 4GB SODIMM in place of a 2 GB one to upgrade to 6GB RAM which they say is allowable for my machine. I had 2x2GB for a long time and it worked well but I just installed a new drive a few months back so I wanted to max out the RAM. Immediately upon installing and the initial boot up, the machine was smoking fast feeling and life was good. The 6GB of RAM showed up as there in the About This Mac menu. I then put the machine to sleep and went to bed. The next day my old lady started complaining about the computer being too slow to use so I rebooted again and it took about 20 minutes to boot up. It's so slow now that it's useless. I powered down, took the battery out and reinstalled the old RAM but the problem persists. Any suggestions as to what to do next? I'd really like to use the 4GB + 2GB arrangement as this 4GB stick wasn't cheap. Thanks in advance.
It's odd that it was working but then it stopped.
As you should be able to see here, Apple recommend 4GB but 6GB is possible. This means you're not going to get any support from Apple themselves.
I would suggest checking the RAM is in the ports correctly, checking About this Mac to see if it still recognises it's there. Try running an Apple Hardware Test, specifically an Extended Test.
It could very likely be a coincidence having nothing to do with the RAM upgrade. Here's something simple and free: download SMART Utility from versiontracker.
I know you said the drive is newish, but I've had brand new drives fail with hundreds of bad sectors (blocks) right out of the box. And extreme slowness is one symptom of bad blocks.
A further thought added later: have you tried booting to an external to see if it's slow running under another system? You need to rule out 1. hard drive failure (use SMART Utility for that) and 2. software (booting to another system would do that.)
'What's your free space overhead on the HD?
More RAM means you need more free space for VRAM.
If you're running lots of RAM the system may still be trying to use VRAM that's not available, and that could slow it down.
Are you certain that you're actually accessing all 6GB of RAM? I can put 4GB in my Macbook but the OS only access 3GB.