Murderously Slow Macbook Pro

[johnsalomon]

Hi there,

I have a 2.4GHz Macbook Pro, 2GB memory, 160GB HD, OSX 10.5.4. All updates are installed, disk has about 90GB free.

The system boots and generally runs fine, unless I open up seemingly random combinations of applications. The machine will nearly freeze up, spinning pinwheel and all. I can switch between application windows, but moving them is very slow and jerky. Sometimes I can close applications, but need about 5 minutes between hitting cmd-q and the application actually closing. Cmd-tab almost never responds.

Inside any application that's open at the moment, I get the pinwheel, which comes and goes intermittently. I can't reboot the machine (at least I can't get a terminal up via Quicksilver, and clicking on the apple menu gives me no response.) I started running istat menus, which show me a maximum system cpu load of about 75-80% (usually around 40-50%), no serious disk IO, and no less than 400-500MB of free physical memory. I started leaving activity monitor open in anticipation of this happening, and sorting by either cpu or any kind of memory usage I get no clue as to what's happening.

The only option is to power-cycle the machine, or to leave it sitting for several hours, in which case it will sort itself out and let me enter commands. Sometimes, I will be able to interact with applications again normally, but occasionally the system will seize up again.

I mainly use Firefox, mail, transmission, office 2k8 and some programming tools, but I cannot find any combination to reliably reproduce the problem. I've run rember to test physical memory, and onyx to check disk structure and run all cleanup/maintenance jobs. System.log prior to the slowdowns yields no clues; console shows a lot of cryptic application error messages, but nothing that looks like it should be crushing my system. I can't hear any disk activity, the fan doesn't speed up notably, and cpu temperature hangs around 57C.

I'm at a bit of a loss here; any hints as to what could be causing this would be appreciated. I'm used to systems becoming unusable, but normally it's for a maximum of about 5-10 minutes at a time while they figure themselves out, and if I have some monitoring tools running, they generally show 100% either cpu, disk or memory usage. Help?

 

[djtrippin]

Try leaving either the system monitor open or leaving a terminal open running 'top'. The next time the computer locks up on you check to see whats eating up processor cycles. Try and leave the monitor window somewhere on the desktop that it wont get covered up so you dont have to worry about tabbing through windows when the system comes grinding to a halt.

 

[johnsalomon]

Try leaving either the system monitor open or leaving a terminal open running 'top'.

Already done both of those -- there doesn't seem to be anything seriously grinding down the system in terms of resources, which is what's weirding me out. Various other real-time commands (iosnoop, vm_stat, etc.) also don't give me many clues as to what might be going on.

 

[logana]

I know you have checked the memory but it still sounds like bad RAM. Try swopping for other RAM if you have any or taking one of the RAM chips out and see what happens - then swapping the chips over.

Sorry cannot be any more help but RAM seems to be the most likely culprit !

 

[MKnight]

johnsalomon,

My other Macbook Pro is the same model as yours and I can tell you 2 very important things. The 160GB 5400 RPM drive in that laptop is actually a terrible performer, so upgrading that to the newer Hitatchi 7200RPM drives will yeild massive benefits.

Second of all, I also run Office2k8 and I find that while using Entourage, it does slow things down a bit. Make sure you have the latest updates for Office as they improve things a lot.

 

[johnsalomon]

I've done some more screwing around and found that the most frequent, although by far not exclusive, culprits are Transmission and Parallels (I don't use Entourage, and oddly enough for MSFT products, Office 2k8 has been behaving rather nicely..

I found a post describing a (supposedly now resolved) bug in transmission that causes some peoples' boxes to exhibit exactly this behavior. Bittorrent is pretty gnarly on disk i/o so that makes sense (although I've not seen this happen with Azureus/Vuze, which is just generally slow CPU-wise; maybe that's a performance bottleneck that prevents it from hitting the disk to the point where it will hang the system, who knows.)

I was mistaken about the drive, it's a 200GB Hitachi (also 5400 rpm), not a 160 -- I will assume they both have the same performance problem. I am getting a massive RAID-5 NAS array from a friend soon, so I'll do as you suggest and swap out the drive for a newer one. While your point about the disk is highly plausible, it just weirds me out that I don't hear any disk activity when the laptop goes pear-shaped.

There are also threads describing similar freezes for Parallels, although for older builds. It doesn't seem to be a disk issue, though -- again, neither iostat nor any other tools show a notable spike in either memory activity or HDD reads/writes, and I also can't hear the drive heads. I'll give it a go later and see what I find, but thanks for the pointer (and I hope that whoever stole your laptop has this happen to them, frequently.)