I'm running the current Mac OS 10.8.2 on a 17" 2009 MacBook Pro (2.9 GHz). I have a 240GB Intel SSD 520 (SSDSC2CW240A3) for my boot/app drive and an additional HDD for data only.

For months now I've noticed the computer freezing up, but it's not instant. Usually I'll be in the Browser (Safari) and it will stop loading or a page will stop. The pointer will generally go to a beach ball. I'll got over to another app and it will seem to be working (Mail) but when I click through onto other messages that are obviously not in memory, they will appear blank, then the beach ball comes up there too. The dock may or may not work during this time and then the beach ball seems to be spinning for every app. I can usually still switch between apps however.

I've been thinking for some time that it's the Intel SSD 520 I've got installed as my boot disk - it's also where all the apps live. But I don't know how I can definitively prove this. Does anyone have any recommendations on how I can track this down, perhaps being able to log any such freeze ups?

I *JUST* now noticed that the OS reports NO TRIM support for this SSD. Which I'm pretty sure I had in 10.7, probably due to a patch. Which I probably didn't install in 10.8. Did I just answer my own question here? Would this be a likely culprit for the symptoms I'm noticing above?

Which bay is the SSD installed in? If it's in the optical bay, this is the exact behavior I saw on a 2011 MBP.

TRIM doesn't matter (really!) unless the drive is mostly full -- say 70% or more full in most cases.

The way to prove or disprove the SSD as the issue, is to bit-copy it to a same (or larger) size mechanical drive, and then boot/run from the mechanical drive. See if the issues persist or not.

Cheers

Tom, I honestly can't remember what bay I put it in. Is there a way I can tell for certain via software without having to crack the bottom case?

Mark, that's going to take even more time than opening the case to verify the drive installation. I may be able to manage it onto a spare drive when I have some time.

You don't say if it comes back from the freeze. If so, how long are the freezes?

You mention "mails not in memory". That shouldn't require much if any writing to the disk where TRIM would come into play.

Even if TRIM isn't working it should just go slow when writing to the disk - not completely freeze (but again I don't see a timeframe on the freeze).

And "slow" for a modern SSD is still blindingly fast compared with a mechanical drive.

Anywhere from 30 seconds to 2 minutes. But I'm guessing here.

System information under Serial-ATA might identify the bays, but I think only the Mac Pro does this. My issue with the 15 inch was that the SSD would negotiate a 3GBit connection in the optical bay, but the cabling really only supported 1.5GBit. The hard drive bay was fine at 3GBit, and potentially 6GBit had I had a compatible drive.

I did find this thread with similar complaints even with the drive in the hard drive bay: http://communities.intel.com/thread/29859

One person said enabling TRIM did seem to help him.

I had forgotten the 530 was the SandForce based Intel drive. Also make sure you have the newest firmware for it. I still don't personally trust them, but YMMV.

I bought the Intel because that's one of the brands everyone seems to universally suggest. The Kingston I had died rather quickly. I just got around to getting an RMA this past week and they're replacing it with a brand new and current product which should be much faster - let's hope it doesn't die - when I figure out what to do with it.

I did a quick Google for firmware for the Intel and didn't seem to find anything - it still has the original.

System Info shows it's only negotiated a 1.5Mbit connection, but it doesn't identify the bays otherwise. The HDD has a 3Mbit connection. Maybe I have them swapped - I know only the primary HDD bay supports sudden drop sensor, but I thought I remember the optical bay having issues with hibernation if it was used for the boot drive. So I really can't remember how I installed them and will probably have to crack the 12 screws (I lost one) to find out.