>> Any results on the test with the other drive? Sorry, pressed Send button during edit. The test results with 2 WD drives, 1. Desktop 500GB 7200 rpm WD5000AKX drive [good S8005GM2NR board] read speed - 127 Mb/s [good S8005GM2NR board] write speed - 124 Mb/s [bad S8005GM2NR-LE] board read spead - 127 Mb/s [bad S8005GM2NR-LE] board write speed - 124 Mb/s 2. Mobile 250GB 5400 rpm WD2500BEVS [good S8005GM2NR board] read speed - 57 Mb/s [good S8005GM2NR board] write speed - 55 Mb/s [bad S8005GM2NR-LE] board read spead - 37 Mb/s (!) [bad S8005GM2NR-LE] board write speed - 30 Mb/s (!) So at least the perfomance dropped with different drive too and the drop is nearly 20Mb/s. I've made another test, trying to exclude the SP52100 - I've used the external PCI SATA controller from Silicon Image Sil3112A, so the two drives - Hitachi and WD were connected to PCI SATA board instead of onboard SP5100, test results below : 1. Hitachi HTS725050A7E630 500GB drive [good S8005GM2NR board] read speed - 88 Mb/s [good S8005GM2NR board] write speed - 80-91 Mb/s (!) [bad S8005GM2NR-LE] board read spead - 35 Mb/s [bad S8005GM2NR-LE] board write speed - 0.9 Mb/s (!) 2. Desktop 500GB WD5000AKX drive [good S8005GM2NR board] read speed - 98 Mb/s [good S8005GM2NR board] write speed - 85 Mb/s [bad S8005GM2NR-LE] board read spead - 96 Mb/s [bad S8005GM2NR-LE] board write speed - 87 Mb/s So the low write perfomance do not depends even from SATA controller, but depends from the HDD and moherboard combination. Can we see (or debug) what is happenning on bad S8005GM2NR-LE motherboard during write ? -- Rus -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html