lee <lee@xxxxxxxxxxxxxxx> writes: > "Wolfgang S. Rupprecht" <wolfgang.rupprecht@xxxxxxxxx> writes: >> The SSD in question is capable of 550 MByte/sec (Intel 520 SSD), while >> the PCIE controller is only an x1 single lane controller which probbly >> saturates the single lane at 480 MByte/sec. I'm assuming (perhaps >> incorrectly) that the controller is choking when it receives more data >> from the SATA than it can transmit on the PCIE. >> >> The bootup kprintf's show a 6Mbit/sec negotiation, but later when I try >> a transfer I see 130 MByte/sec transfers for a raw partition dd, hinting >> strongly that it is now talking at 1.5Mbit/sec on the SATA. I'm >> wondering if it is silently downshifting the SATA speed. In comparison, >> a slower SSD rated at 250MBytes/sec (which can stay within the PCIE x1 >> lane budget) runs at full speed, of slightly over 250MBytes/sec on the >> same controller. > > Have you tried to change the SATA cable? You could switch them over and > see what happens ... Yes. I've even swapped cables and SATA port between the good SSD that runs at 250MBytes/sec and this one. Same results and the other SSD still ran at its 250MBytes/sec on the cable and port the mis-behaving SSD was on. -wolfgang -- g+: https://plus.google.com/114566345864337108516/about -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
