Bekijk de volledige versie : WL-HDD IDE Speed -- Could be faster?

17-09-2005, 19:34

I have an ATA-100 drive in my WL-HDD and I suspect that it's running slower than 100MHz. Based on some other WL-HDD performance discussions, this may not matter in the grand scheme of things, but I'm still curious. I was sifting through the kernel log and early on it says:

kernel: ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx

Later, I see:

kernel: ide0: BM-DMA at 0x0140-0x0147, BIOS settings: hda:DMA, hdb:pio

which suggests that my harddrive (hda) is actually using DMA and not PIO. So far so good. Later still I see:

kernel: hda: 195371568 sectors (100030 MB), CHS=12161/255/63, UDMA(33)

which suggests that I'm using UDMA (good) but only at 33MHz (bad). At the shell prompt, cat /proc/ide/hda/settings reports (among other things):

name value min max mode
current_speed 66 0 69 rw
using_dma 1 0 1 rw

Does this mean the harddrive is actually using UDMA66? Can I jack it up to 100 somehow?


17-09-2005, 23:03
I guess that any (U)DMA speed: 33, 66, 100 or 133 will give you the same performance and that the critical part of the performance is the (U)DMA/PIO setting. A harddisk with (U)DMA 33 speed will deliver far more data to the processor than the processor can handle.

18-09-2005, 17:37
Use hdparm to adjust your harddisk settings... but you wont get any faster speed than 6-8 MB/s at all.
hdparm is not in Oleg's firmware, so you have to get it via ipkg or search for it in the forum.

Test your speed with: hdparm -t /dev/discs/disc0/disc