4MB/s Read Speed On A WD 500GB Drive

It could just be a fluke with the drive itself. Not necessarily something diagnostically wrong, but perhaps something else. I'm no hard drive manufacturer, so I couldn't give you specifics, but who knows....

Try another drive, same make, if you can. That should help you figure out if its the drive itself or not.

Also, maybe you need to do some driver downloading. Maybe a different/updated SATA driver would make a difference.

Hace you checked for new firmware?  Are the other drives the same model or different models?  Can you run the WD Diags and post the results here with the threshold values please?

So I should try another driver? The MB is Asus P5G31D-M Pro(G31 + ICH7), I got the drivers from their site. Where can I get other versions that would work with this MB?

Btw I'm not quite sure what you mean by "Try another drive, same make", do you mean get another drive with the same model any try again?

Thanks for your help.

If you have not made any configuration changes, then this is a typical indication of a failing disk drive.  (Bad blocks).  

Is this a newer WD I know their newest advanced format drives need to have be aligned to work properly with windows.  They have a utility to do the alignment on their website.

Well I'm currently preforming the WD Diags again and will paste the results once I get them.

StrifeJester: Could you please kindly provide me a link or at least the name of that utility?

Thanks.

Ok I just downloaded & ran the WD Align System Utility, but it showed the following :

Please wait one moment while partitions are detected.

Scanning system for Western Digital Advanced Format drives:

Disk: 0: WDC WD5001AALS-00L3B2 : Western Digital Drive : Non-Advanced Format
Disk: 1: Hitachi HDS721010CLA332 : Non-Western Digital Drive

2 Hard Drives were found : No Advanced format drives were detected. All drive pa
rtitions are properly aligned to achieve optimal performance and are ready for u
se. Press Enter to exit utility and return to the OS

Strike any key to continue..

All the WD align program does is align the starting block of your partition so you MIGHT squeeze a few more percentage points of performance out of it.  There is no magic, and you can and should do this with all HDs, regardless of make/model.   This is by no means a requirement for using this or any other make/model of disk with any O/S.  

Ok so no advanced format and usually WD doesn't make firmware available lets see what the results look like from their diags but I think you just have a flaky drive and its going to need replacement.  Can you place the drive in a different ssytem and test it?  Also do you have the Intel drivers or the Microsoft HDD controller drivers loaded.  To check go into the device manager and expand the Controller and click on properties it will tell you who the driver is from there.  Make sure also on the channels that DMA is enabled on the IDE Channel the HDD is on.

http://hothardware.com/Articles/WDs-1TB-Caviar-Green-w-Advanced-Format-Windows-XP-Users-Pay-Attention/?page=2

A little off topic since this is not an Advanced format drive but the performance gains achieved by aligning the HDD are anything but minor.  Its over 40% using an aligned drive compared to a non-aligned one.  There are the benchmarks in that link that explain it better.

Is the drive still under warranty?  You will want to do a check for that as well here on WDs website:

http://websupport.wdc.com/warranty/serialinput.asp?aspsid=770957360&custtype=end&requesttype=warranty&lang=en