Help Troubleshooting Hard Drive Problem on Mac OS 10.6? (Resolved, Fix in Last Post)

Last night I installed a 1 TB internal drive in my Macbook Pro to complement my SSD (I have no CD drive). 60% of the time, performance is great. The other 40%, it hangs severely and can't read or write anything for several seconds. Does anybody know what could be causing this? For reference, here's what disk usage looks like during a large copy operation (notice it flatlines at 0, even though the copy is still going):



This drive is a Western Digital, but I had the same problem with a 1 TB Samsung a little while back. Samsung told me the drive was defective, but given I'm having the exact same behavior with a different drive, I'm thinking it's not a hardware issue after all.

I formatted the drive with the Mac OS Extended (Journaled) file system. Running repair from disk utility finds no issues. I have tried disabling Apple's Sudden Motion Sensor and disabling Spotlight indexing on the drive. Neither makes a difference.

Temporarily split it into two partitions to run a couple tests, but not planning to keep it that way. Here is what System Profiler reports:

WDC WD10TPVT-00HT5T1:

Capacity: 1 TB (1,000,204,886,016 bytes)
Model: WDC WD10TPVT-00HT5T1
Revision: 01.01A01
Serial Number: WD-WXB1AB0T3611
Native Command Queuing: Yes
Queue Depth: 32
Removable Media: No
Detachable Drive: No
BSD Name: disk1
Rotational Rate: 5200
Medium Type: Rotational
Partition Map Type: GPT (GUID Partition Table)
S.M.A.R.T. status: Verified
Volumes:
Capacity: 209.7 MB (209,715,200 bytes)
Writable: Yes
BSD Name: disk1s1
Media HD:
Capacity: 386.61 GB (386,612,887,552 bytes)
Available: 99.27 GB (99,267,100,672 bytes)
Writable: Yes
File System: Journaled HFS+
BSD Name: disk1s2
Mount Point: /Volumes/Media HD
Media HD 2:
Capacity: 613.11 GB (613,113,806,848 bytes)
Available: 409.97 GB (409,971,826,688 bytes)
Writable: Yes
File System: Journaled HFS+
BSD Name: disk1s3
Mount Point: /Volumes/Media HD 2


Much appreciation in advance for any help.

 

Thanks. Yes, 100% positive it's the HDD and not the SSD that is hanging.

 

Problem solved! Wanted to post the solution in case anybody else stumbles into this.

I downgraded my EFI to 1.6 and that seems to have done the trick. Got the idea here and used the instructions here.

Pretty irritating that this got broken since 1.6 and I'll need to be careful about future software updates, but I'm happy for now.