JEO
2008-07-16, 06:26 PM CDT
I notice my hard disk access speeds were poor afer a suspend/resume. I found out why. At boot time the transfer mode is set to:
Excerpt from hdparm -i /dev/sda
PIO modes: pio0 pio3 pio4
DMA modes: mdma0 mdma1 mdma2
UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5
Excerpt from hdparm -I /dev/sda after a suspend/resume cycle:
DMA: mdma0 mdma1 *mdma2 udma0 udma1 udma2 udma3 udma4 udma5
Cycle time: min=120ns recommended=120ns
PIO: pio0 pio1 pio2 pio3 pio4
Notice the crummy mdma2 mode it's in. It should be in udma5 mode. My question is, besides rebooting, how can I change it back? hdparm -d returns nothing, no dma setting (probably because they are the new libata drivers).
Edit: running FC8 32 bit, all current updates. Drives are PATA 80GB Western Digitals (I have 2 in a mirror and the results for /dev/sdb is the same as /dev/sda).
Excerpt from hdparm -i /dev/sda
PIO modes: pio0 pio3 pio4
DMA modes: mdma0 mdma1 mdma2
UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5
Excerpt from hdparm -I /dev/sda after a suspend/resume cycle:
DMA: mdma0 mdma1 *mdma2 udma0 udma1 udma2 udma3 udma4 udma5
Cycle time: min=120ns recommended=120ns
PIO: pio0 pio1 pio2 pio3 pio4
Notice the crummy mdma2 mode it's in. It should be in udma5 mode. My question is, besides rebooting, how can I change it back? hdparm -d returns nothing, no dma setting (probably because they are the new libata drivers).
Edit: running FC8 32 bit, all current updates. Drives are PATA 80GB Western Digitals (I have 2 in a mirror and the results for /dev/sdb is the same as /dev/sda).