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Uncle Skeleton · Mar 14, 2011, 04:36 PM

Ok, here goes. I tried to search but I can't even think of any valid search terms.

A lot of times when I first open a Netflix streaming movie (other times too, but this is most common), it will be just terrible, and the cpu is pegged full on. Pausing the movie to let it buffer brings the cpu down to about 90%, but it still can't play smoothly. Now here's the weird part: if I open Activity Monitor usually Safari is using most of it, but simply selecting Safari in Activity Monitor immediately makes it drop its usage to almost nothing. Then I can close Activity Monitor (or not), and the movie plays flawlessly from then on.

Now, I like being able to do this "fix," I really do, but WHY is it happening?

ibook_steve · Mar 14, 2011, 07:06 PM

Weird.

I don't have an explanation for what you are seeing, but the first thing I would do would be to reinstall the plugins that Netflix uses for streaming.

Have you tried another web browser to see if the problem still occurs?

Steve

turtle777 · Mar 14, 2011, 08:19 PM

Just tried to replicate that issue, but I couldn't.

-t

Uncle Skeleton · Mar 15, 2011, 12:49 PM

It is on a pretty slow laptop, so when Netflix is streaming normally it takes like 80% of the cpu. I've noticed it on my Mac Pro too, but maxing out 1 of 4 cpus there doesn't really hurt me, so I never follow-up there.

I'll try it with a different browser today and see if it happens

Uncle Skeleton · Mar 15, 2011, 08:04 PM

It happened again today, despite updating Silverlight (the streaming video platform netflix uses) and switching to Firefox. This time I tried not selecting the browser, just opening Activity Monitor and waiting. It still stopped, so selecting it at least is not part of it.

I'm still looking for ideas on why I would change the outcome by measuring it. Schrödinger's Mac?

reader50 · Mar 16, 2011, 02:12 AM

Try selecting other processes, see if when you click, the CPU load changes.

Perhaps Activity Monitor does an instant update for the clicked item, not waiting for the usual update cycle. And you happened to click after the load had dropped, but before the usual update.

Activity Monitor does not do that under Leopard or earlier, not sure about SL.

besson3c · Mar 16, 2011, 02:32 AM

Perhaps clicking on the process in Activity Monitor changes its "nice" value?

Uncle Skeleton · Mar 16, 2011, 12:32 PM

Originally Posted by reader50

Try selecting other processes, see if when you click, the CPU load changes.

Perhaps Activity Monitor does an instant update for the clicked item, not waiting for the usual update cycle. And you happened to click after the load had dropped, but before the usual update.

Activity Monitor does not do that under Leopard or earlier, not sure about SL.

Oh I forgot to say, I'm watching the total system load in MenuMeters the whole time, that is how I know there is a problem (high load while it should be idle). MenuMeters is what drops to nil shortly after I open Activity Monitor. I have tried waiting variable lengths before opening Activity Monitor

Uncle Skeleton · Mar 16, 2011, 12:34 PM

Originally Posted by besson3c

Perhaps clicking on the process in Activity Monitor changes its "nice" value?

How can I test this theory? Actually it doesn't make sense to me because shouldn't that only affect it if another process wants the resources? In this case it is dropping the total system usage (according to MenuMeters), not just that process to make way for another one.

This is 10.5 by the way

besson3c · Mar 16, 2011, 12:54 PM

Originally Posted by Uncle Skeleton

How can I test this theory? Actually it doesn't make sense to me because shouldn't that only affect it if another process wants the resources? In this case it is dropping the total system usage (according to MenuMeters), not just that process to make way for another one.

This is 10.5 by the way

You can compare the nice values before and after you do this trick.

Big Mac · Mar 16, 2011, 01:45 PM

I don't know if this applies to what you're seeing Uncle, but in the past I've noticed that sometimes Activity Monitor reports processor utilization spikes until you open up its window, and then the spike goes away. It's been my assumption that the spikes aren't real but instead some kind of glitch in Activity Monitor or top that underlies it. I used to see this on my G5 commonly. You may think that the processors are pegged because that's what you see, but it may not really be the case.

Uncle Skeleton · Mar 16, 2011, 03:56 PM

How do I check nice values?

It could be a measurement error, except that the streaming video is really terrible before, and smooth after.

besson3c · Mar 17, 2011, 01:44 AM

Nice values are visible through top/Activity Monitor... The fields are explained here:

top - Linux Command - Unix Command

Spheric Harlot · Mar 26, 2011, 04:52 AM

Originally Posted by Uncle Skeleton

Oh I forgot to say, I'm watching the total system load in MenuMeters the whole time, that is how I know there is a problem (high load while it should be idle). MenuMeters is what drops to nil shortly after I open Activity Monitor. I have tried waiting variable lengths before opening Activity Monitor

Make sure you're using the latest version of MenuMeters.