MyTwistedSister, on 19 November 2012 - 11:20 AM, said:
I just managed to get my Snow Leopard I-Mac functioning again after one month but it is VERY SLOW. I have downloaded Cocktail and Onyx to use but I am also checking the ACTIVITY MONITOR but I need to know how to interpret what I see. For example, where it says "threads" it may show 20 or 30 or more. Is that abnormal?
It looks like it was jammed with too much stuff at once and thus the spinning wheel status for a month but that's just my guess.
Can someone tell me what NORMAL looks llike on Activity Monitor? What should I watch for? Thanks.
Primarily, you want to pay attention to CPU load. What you might be able to expect depends on what particular machine you have, but the peak value for CPU load is 100% times the number of processor cores in your system. So a Core 2 Duo model could be as high as 200% and a current quad-core Core i5 could be 800% (because the CPU offers virtual cores, and yes I've seen a single process on my MBP approach 800% CPU utilization).
You'll also want to take a look at virtual memory usage but I don't recommend using Activity Monitor to try to work that out. Instead run the application named Terminal and type the command "ls -lr /var/vm" then count the total size of the swap files listed. One or two files is not a problem, but if you're seeing several hundred MB or more there may be a problem. You might have a single runaway process really chewing up space - and that you'd be able to see in Activity Monitor pretty clearly - or you may simply be asking more from your machine than it's realistically capable of now.
Some things to not be worried about automatically: Double-digit thread counts aren't a problem. Threads are how applications divide up work to keep the time taken manageable and keep the UI responsive. How many is "right" depends on the individual app and what it's doing. The reason I recommend against using Activity Monitor to check VM usage is that the easiest VM number to see in there doesn't really mean what most people think it means. The way VM works on many systems ends up treating all application code as part of the VM allocation. Not just the core application but every library it uses. So that number is much higher than what it's really using in terms of transient disk space. Finally, don't get fussed about seeing your "free" memory number being especially low. That's not a problem in and of itself. If you do find a lot of VM allocation via that terminal command, then you'll likely see a low free count as a second symptom of the fact that your processes are using more memory than your system has. But if the VM allocation is low, then a low free count is actually a good thing.