Sudden and very slow performance from second HDD?

Thanks for replying!

I went into HD Tuner, but there's no health info for the drive, the tab is just blank. It looks like I'll need to confirm that SMART is enabled, right? I'm at work now, so that will have to happen later, but I'll post as soon as I get a chance.

Sorry I haven't gotten back to you on this until now. I've been trying to get SMART monitoring enabled so that I can get you the health info. However, for the life of me I cannot find where to do so. The drive says it is SMART capable, but nowhere in the BIOS can I find the option to turn it on. My motherboard is a Gigabyte Z77 UD5H, and both drives are set to AHCI mode

HD Tune wouldn't show any info, but I was able to get something out of SpeedFan. It looks like it may have an idea of what's going on. It recommends replacing the drive, which while not ideal, may just have to happen. Is there anyway of correcting this blocking error otherwise?

Your hard disk is a WDC WD20EARS-00MVWB0 with firmware 51.0AB51.
The average temperature for this hard disk model is 31°C (min=22°C max=42°C) and yours is 26°C.

Attribute Current Raw
Raw Read Error Rate 175 000000001C57
Spin Up Time 253 0000000004B8
Start/Stop Count 86 000000003770
Reallocated Sector Count 200 000000000000
Seek Error Rate 200 000000000000
Power On Hours Count 78 000000004066
Spin Retry Count 100 000000000000
Calibration Retry Count 100 000000000000
Power Cycle Count 100 000000000360
Power Off Retract Count 200 000000000171
Load Cycle Count 180 00000000EE5B
Reallocated Event Count 200 000000000000
Current Pending Sector 198 0000000002AD
Offline Uncorrectable Sector Count 200 0000000000E3
Ultra DMA CRC Error Rate 200 000000000000
Write Error Rate 190 000000000A8A

All the attributes of your hard disk are above the S.M.A.R.T. thresholds set by the manufacturer. This is good.

BLOCKING ISSUE : your hard disk has 685 pending sectors (this value is very large and your hard disk should be replaced). Those are sectors that couldn't be properly read and that the hard disk logic is waiting for a write operation to try to remap to a spare sector (if available). According to the Reallocated Sector Count attribute, your hard disk seems to have available spare sectors. A simple disk surface scan won't be enough to force the remap operation. You need a read/write surface scan to remap the sector. The best option should be a tool that knows about what should be read from that sector so that it has some option to apply the best fix to the missing data.

BLOCKING ISSUE : your hard disk has 227 offline uncorrectable sectors (this value is very large and your hard disk should be replaced). Those are sectors that an offline scanning found as unreadable. Offline scanning is a process that can be automatically started by the hard disk logic when a long enough idle period is detected or that can be forced by some tool. Those unreadable sectors are identified and the hard disk logic is waiting for a write command that will overwrite them to try to remap them to spare sectors (if available). According to the Reallocated Sector Count attribute, your hard disk seems to have available spare sectors. A simple disk surface scan won't be enough to force the remap operation. You need a read/write surface scan to remap the sector. The best option should be a tool that knows about what should be read from that sector so that it has some option to apply the best fix to the missing data.

NOTE : your hard disk Power On Hours Count attribute current value (78) is below the normal range (96 - 100) reported for your specific hard disk model. Basically your hard disk was powered on for more than the maximum time the average user did. This means that either all of the reports collected are from hard disks that were not powered on for too long (this is realistic for recent models) or that your hard disk is becoming old. Usually this is not considered as a pre-failure advisory, but you should check whether you want to replace the hardware or keep an eye on its performances over time.

The overall fitness for this drive is 0%.
The overall performance for this drive is 97%.

The link to get back and see a new report about this hard disk in the future is this. Consider that new hard disks and new checks are added over time.

Here's a link to the results: In-depth Report

Another question: Does anyone know what would have caused this blocking issue? Was it just a bad drive, or was it something I did somehow? Just wondering so that I don't do it again.

Also, if it comes to replacing the drive, can I leave the old one in as a (poorly perfoming) third drive, or would that hurt the system?