Penryn MBP with 7200rpm HDD: Slow performance with lots of disk activity

[TheJackal]

Hey everyone,

I've got a 6 month old Penryn MBP with the optional 200GB 7200rpm HDD and when I'm either opening up multiple applications like iGetter and then Safari, I notice that Leopard gets really slow with heavy disk access.

I can replicate this by using for example iGetter with 4 multiple downloads on a 18Mbps Cable line and then opening up about 5 or 6 tabs in Safari. Safari will just sit there with the spinner, completely unresponsive, until I pause the downloads.

Those 4 downloads is roughly 1.98MB/s which isn't that much, for a 7200rpm I would expect better performance! Or is it Leopard's filesystem which isn't keeping up?

 

[misterredman]

Does it happens with other programs or only when you are using iGetter? Maybe the problem is related to that program.

 

[gnasher729]

Hey everyone,

I've got a 6 month old Penryn MBP with the optional 200GB 7200rpm HDD and when I'm either opening up multiple applications like iGetter and then Safari, I notice that Leopard gets really slow with heavy disk access.

I can replicate this by using for example iGetter with 4 multiple downloads on a 18Mbps Cable line and then opening up about 5 or 6 tabs in Safari. Safari will just sit there with the spinner, completely unresponsive, until I pause the downloads.

Those 4 downloads is roughly 1.98MB/s which isn't that much, for a 7200rpm I would expect better performance! Or is it Leopard's filesystem which isn't keeping up?

I'd say this is a typical case of looking at the wrong thing. What might be happening is that iGetter completely grabs hold of everything your Internet connection can provide, and Safari is waiting for some tiny amount of data and can't get it.

Did you have a look at Activity Monitor at all, so that you have at least a bit of information what is going on?

 

[TheJackal]

I don't think its specific to iGetter or even related to the saturation of downstream bandwidth as I've throttled downloads to isolate this and I get the same sort of behavior.

Its definitely related to increased disk activity by one single process (for examples iGetter or even iMovie) because as soon as I stop the application "hogging" writes/reads to the disk, Safari opens up every tab flawlessly.

 

[TheJackal]

Sorry to digg this thread up again but I've run Activity Monitor when downloading and I've got the following two screenshots:

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I'm not sure if the I/O (at its peak) is too excessive or even the speed at which writes are being committed to disk are high but if you take a look at Safari in the background, I try to open a new website by typing "www." and it takes at least 3 second before I'm shown the autocomplete list.

I'm pretty sure this is related to the kernel's scheduler as its way too busy servicing the filesystem processes than anything else!