hi guys, i have a problem with a WD hdd.i didnt noticed a slow down in write operations - 3MB/s, only when i try copy large files from another hdd -ST3808110AS to WD drivre.the read speed is ok, 63 mb/s. first i opened HD Sentinel and looking for Realocation event count, since WD drive have 3 realocations with 7 realocated sectors.(at first detection of instable sectors - moths ago, i run a write test from HD sentinel, and hdd has stabilized since then, no other sectors reappeared no other problems that could affect the life of the drive) i didnt noticed the "Ultra ATA CRC Error Rate" has increased from 6 to 9! on M$ page i read this : "For repeated DMA errors.Windows XP will turn off DMA mode for a device after encountering certain errors during data transfer operations. If more that six DMA transfer timeouts occur, Windows will turn off DMA and use only PIO mode on that deviceFor repeated DMA errors.Windows XP will turn off DMA mode for a device after encountering certain errors during data transfer operations. If more that six DMA transfer timeouts occur, Windows will turn off DMA and use only PIO mode on that device.." I found this page after a search DMA revert to PIO. before running the script that enable the DMA, i looked on device manager, but the drive is under DMA if available - UDMA mode 6! My pc specs: Processor: AMD Phenom™ 9550 Quad-Core Processor, x86 Family 16 Model 2 Stepping 3 RAM:2x2 GB Corsair XMS2 CM2X2G8500C5D2 Graphics Card: NVIDIA GeForce GT 220, 1024 Mb Motherboard: ASUSTeK Computer INC., M3A32-MVP DELUXE HDD: WDC WD2500KS-00MJB0 (WD-WCANKD700665) 250 GB - OS drive and other files ST3808110AS (5LR2D0XG) 80 gb - files The amd sata controller SB600 is set to ide mode since under ahci mode no acces to SMART or monitor the drives temp! i tried everything i know! swiching sata cables, different ports , even on the marvell 6121 same! tried to do a drive regenation, same write speed - 3mb/s after! unninstaled ide driver to resset dma! nothing seems to work! im running out of ideas! i do some test on drive, short test - extended - conveyance! drive seems to be ok., no problems under the smart attributes! if could be a write head problems?! the smart should be showing this or the hdd controller is dying - well this could be drive failure!!! i booted in parted magic, formated the drive in fat32 even in a ext4 partition same file transfer!!! here are screensshots!