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k2director · Aug 28, 2006, 01:02 AM

I have a Mac Pro (3Ghz) which came with a stock 250 GB Western Digital Caviar SE hard drive. There's some kind of problem when large amounts of data are being written to that drive, but not any other drives I've installed. Any idea why??

Here's more info...

THE PAUSES OCCUR DURING WRITES FROM THE DVD, AND OTHER HDs, TO MAIN HD
I first noticed the problem when I was installing Final Cut Studio onto the drive - as each FCS DVD was installing, I was surfing the web, and downloading some apps, and kept noticing a spinning beach ball for 10-15 seconds at a time. The installation would go on for a couple of minutes, then the beachball for 10-15 secs, then the installation would continue for a few minutes, and so on.

I have 5 gigs of RAM installed, so I didn't think it was a case of ram bandwidth.

Later, I installed 3 additional, brand new Maxtor hard drives in the system. 2 300s, which I stripped together into a RAID 0, and a 500 gigger as well. And whenever I try to copy any appreciable # of files from the main drive to any of these new drives, or from the new drives to the main drive, the system will again freeze for 10-15 seconds at a time, every 45-60 seconds, during the copy. During this freeze, the copying itself will pause, all apps will stop, iTunes will stop playing, etc., and then, 10-15 secs later, the machine will come back to life, and the copy resumes....until the next freeze 45-60 secs later.

BUT NO PAUSES OCCUR WHEN OTHER HDs WRITE TO EACH OTHER
However, this problem DOES NOT occur when I try to copy an appreciable amount of data between ANY of the Maxtor drives. The copies go fast and smooth, and I can do plenty of work in the background.

MY CONCLUSIONS
Clearly, the problems all occur when the main Western Digital Caviar SE drive is having large amounts of data written to it, either from the DVD drive (Final Cut Studio install), OR other internal hard drives. So....

Any ideas why, or how I can fix this problem??

Any help MUCH appreciated, thanks!

Big Mac · Aug 28, 2006, 02:03 AM

When you say "pauses," do you mean jittery performance or outright perioidic freezing in which nothing updates on screen or beach balling occurs in every applications for ten to fifteen seconds? If it's just jittery/stuttering performance, that's to be expected to some degree because the drive cannot be in two places at once - if it's reading or writing a substantial amount, it makes it more difficult to concurrently service the data requests of applications on the same disk. You'll have to describe the issue a bit more specifically, I think.

k2director · Aug 28, 2006, 02:44 AM

Hey there,
The machine stops all operations cold--ie, the data copying itself will pause, all apps will stop, iTunes will stop playing, the screen doesn't update, no windows can be selected, web pages don't scroll when I thumb the scroll wheel on my mouse, Expose doesn't work, etc. etc. etc.., and then, 10-15 secs later, the machine will come back to life, and the copy resumes, along with all other functionality...until the next freeze 45-60 secs later.

It's definitely wayyyyy beyond jittery or stuttering performance....

Big Mac · Aug 28, 2006, 03:50 AM

Now I see what you're saying. It sounds like a problem with the drive itself. What if you were to clone your startup drive on to one of the other drives and test it to see if the same problem occurs?

k2director · Aug 28, 2006, 04:22 AM

Yea, I thought about that, and may have to do it. But it will be a major pain and involve juggling a bunch of files between drives, due to the fact that 2 of the other, non-problematic drives are currently raided together.

I'm hoping I won't have to get to that point. It seems SOMEONE would have encountered this kind of glitch at some point, but we'll see! Thanks for the help, though, Big Mac...

macgeek2005 · Aug 28, 2006, 10:17 AM

The Drive that ships in the Mac Pro is a Western Digital? oh god..... oh god....

I'm definetaly using a 320GB 7200.10 Seagate Barracuda from Newegg as my main disk....

OreoCookie · Aug 28, 2006, 11:05 AM

Your harddrive probably has some defective sectors, so it takes a long time if MacOS tries to access those faulty sectors.

awcopus · Aug 28, 2006, 11:16 AM

Undo your RAID 0 config and run some tests.

Switch the Western Digital drive with one of your other HDs. If you still have problems, the freezing may be a Logic Board issue involving the bus that the first HD is installed in. If your problem goes away or is repeatable when you isolate data transfers with the Western Digital drive, lose the drive (have Apple replace it actually).

Good luck. I hope your logic board isn't screwed up. Repair times are not particularly quick for this kind of thing.

k2director · Aug 31, 2006, 04:15 PM

Thanks for the help/advice, all. I did a bunch of tests, and determined that my machine is indeed messed up. A brand new, perfectly functioning drive in Bay 1 exhibited the same problems as Apple's stock drive. In other words, ANY drive in Bay 1 shows the same problems, so Bay 1 is the culprit. Called Applecare, and they're getting back to me as to whether they do an on-site repair, or if they take the machine back.

Xyrrus · 02:11 PM

Originally Posted by k2director

Thanks for the help/advice, all. I did a bunch of tests, and determined that my machine is indeed messed up. A brand new, perfectly functioning drive in Bay 1 exhibited the same problems as Apple's stock drive. In other words, ANY drive in Bay 1 shows the same problems, so Bay 1 is the culprit. Called Applecare, and they're getting back to me as to whether they do an on-site repair, or if they take the machine back.

I'm a little curious about this, actually because I experienced the same sort of behaviors last night while doing installs. I figured it was just the optical drive hogging the system resources or the installer being poorly behaved.

Can you expand on your issues and tests at all? At what point did applecare say there was a problem and did they have any guesses as to what it was?

edit: anyone else notice pauses while installing? I don't have the machine infront of me here, so I can't test if it was just installing stuff off the optical drive.

Also, can you swap the bay 1 drive into bay 2 and see if there are still problems? I've got a spare 160 gig SATA drive that is currently 100% empty so I can at least do some testing if need be.

-Xy

k2director · Sep 7, 2006, 02:56 PM

Any drive in Bay 1 exhibits the problems--ie, causing the Mac to stop working for 10-15 secs at a time when doing large reads or writes from the drive in Bay 1.
The best way to see if you have my same problem is to install a second hard drive into your Mac, and then try to do a large copy between Bay 1 drive and Bay 2 drive.

The Applecare folks were very quick to take the machine back. They say that when they encounter a strange issue in new hardware, they like to "capture the machine in the wild", bring it back, and analyze its problems, rather than simply do a parts swap. So that's what they're doing with my machine. I should have my new Mac Pro by tomorrow, or early next week. When it arrives at the local Apple Store in LA, I take my old Mac Pro into the store, and they'll do an exchange...

chefpastry · Sep 7, 2006, 03:16 PM

Please follow up and let us know if the problems are resolved with the new machine. Thanks in advance!

Xyrrus · Sep 7, 2006, 03:43 PM

Originally Posted by k2director

Any drive in Bay 1 exhibits the problems--ie, causing the Mac to stop working for 10-15 secs at a time when doing large reads or writes from the drive in Bay 1.
The best way to see if you have my same problem is to install a second hard drive into your Mac, and then try to do a large copy between Bay 1 drive and Bay 2 drive.

The Applecare folks were very quick to take the machine back. They say that when they encounter a strange issue in new hardware, they like to "capture the machine in the wild", bring it back, and analyze its problems, rather than simply do a parts swap. So that's what they're doing with my machine. I should have my new Mac Pro by tomorrow, or early next week. When it arrives at the local Apple Store in LA, I take my old Mac Pro into the store, and they'll do an exchange...

One clarification: The problem occurs when copying from bay 2 to bay 1, but NOT when copying from bay 1 to bay 2? That is, its related only to *write* access to bay 1?

Also, did the size of the file matter? Would a 3GB test file be the same as a large number of smaller files? (The former is easier to put together a test for)

I'll probably try copying a test file from a DVD to each of the drives, then swap the bays that the drives are in and try again. (Can you boot the OS off of a drive that isn't in bay 1?) That should give me a pretty good idea if its just my imagination or not

Again, I hadn't given it a second thought until I read this thread today.

-Xy

Xyrrus · Sep 8, 2006, 11:59 AM

A quick follow up for anyone who cares. I copied both a 6 gig disk image and a 40 gig itunes library to and from each drive, then swapped the two drives and repeated the procedure but wasn't able to duplicate anything like I'd expierenced during the initial final cut install off of DVD. I'm going to keep an eye on the system over the next month and see if anything crops up again. I'm chalking up any percieved abnormalities to "new machine jitters" until then.

When copying the files the machine did slow down appreciabley, safari would take much longer to render a page, for instance. I'm thinking this is normal; safari was trying to write its cache at the same time the finder is trying to write the library/image.

-Xy