Original title: Slow SATA disk writesRunning Win XP SP2 on an Asus P5KSE motherboard, with 2 SATA HDs, one with WinXP, and the other with data. After a few months, I installed SATA disk caddies, and to make sure these did not impact disk performance, ran a benchmark before installing, and then again after installing. The results on both disks were as follows: Disk Writes: 50Mb/sec, Disk Reads: 700 Mb/sec. A few months later, I discovered that both disks had slowed dramatically for some unknown reason. I ran the benchmark again, and the results now are: Disk Writes: <10Mb/sec, Disk Reads: 700 Mb/sec. A few months ago, I installed two USB to SATA external hard drive adapters, and put the data SATA drive on one. The benchmark shows Disk Writes on USB at 25Mb/sec, so the disk itself is not faulty.I have tried refreshing drivers with no success. I even recreated Windows XP on another SATA drive (new), and still get the problem.What on earth could cause SATA disk writes to slow down so dramatically? Is it possible adding the USB enclosures has "upset" the IDE controller?Any ideas welcome!

Hi,1. Do you run Disk Defragmenter and disk checking regularly?2. Have you enables disk write caching?Connect the hard drives to different SATA portson the motherboard and check if it helps.Also, enable disk write caching.Follow these steps:a. Click on start and then go to My Computer.b. Select the drive and then right click on the drive and select properties.c. Click on the hardware tab.d. Select the hard drive.e. Click on the properties button and then click on policies tab.f. Select the option 'Enable write caching on the disk'.e. Click on Ok.Also refer these articles:How to Defragment Your Disk Drive Volumes in Windows XP:http://support.microsoft.com/kb/314848How to perform disk error checking in Windows XP:http://support.microsoft.com/kb/315265Regards,Afzal Taher-Microsoft Support.Visit our Microsoft Answers Feedback Forum and let us know what you think.

Thanks for quick response!I had already tried all these ideas with no improvement. All disks have been defragmented, write caching is enabled, and I have also tried shifting both drives to different SATA ports, with no improvement. The disks have also been error-checked recently. I did try switching one of the affected drives to a USB2-SATA adapter, and the write throughput was dramatically improved - up to 25MB/sec. This proves the disk is OK, and whatever is causing the problem does not apply to the USB setup.Les