Upgrade from SL > Poor performance.

Clean install. You did this before why not this time?

 

Could the problem not be with Lion and maybe with something else like Onyx?

 

Check for the apps and extensions that are not supported in lion anymore,
delete those and defragment your disk. That should do it.
Of course back up first!

 

Mac OS X does automatical defragmentation.

 

Not true. It is supposed to so for files up to 20 mb, but even files in that weight range are all around the place.
It is really easy to check, just run one of your defragmenting tools and check it for yourself, you will be surprised how messy your hard drive is.

 

What you describe might be your case, but, quite certainly, isn't mine. You might want to check the particulars of your system.

 

I second your observations, but I did a different type of "clean" install. Knowing that I have a bit of cruft on my machines, I first backed up my data, performed a clean install of Snowy, installed my apps, then performed the upgrade to Lion. Everything runs really smoothly, but some apps (like GeekTool, for example) are a bit quirky. Safari, no lie, DOES run a lot snappier, thanks to the new javascript engine IIRC. All I know is that it was like a night and day difference between Safari under Snowy and Safari under Lion. I really like Lion, and I think this will be a hugely successful OS for Apple.

 

Lion runs like **** for me as well. iStat doesnt work at all, lion wont let me touch it, i cant even delete it from my dashboard, it just crashes if i scroll over it. i get lag when starting up on my lockscreen and random lag all over the place., chrome runs like **** it takes like 5 or 6 bounces to open, sometimes my dock sticks on the screen (i have it on autohide). I am experiencing SO many bugs! on an upgrade from SnowLeopard to the lion GM.

I might as well do a clean install tomorrow when lion is released. I hope the bugs do not come back.