RH7.2 only supports up to ATA33!!!

[otheos]

Now I find it difficult to believe it but I have tested many drives that have max STR in the ~40MB/s range and NONE works any higher than 26MB/s (which is about what ATA33 minus overhead is).

Now add to that the fact that hdparm -X67 /dev/hda verboses (syslog) this:

Nov 4 14:16:57 Slacker kernel: ide0: Speed warnings UDMA 3/4/5 is not functional.

Same for -X68 (ATA66/UDMA4) and -X69 (ATA100/UDMA5).

Obvioulsy -X34 (DMA2, 16.6MB/s) works and allows the drive to around 13MB/s (in hdparm -t), then you change to -X66 (UDMA2/ATA33) and it jumps to 26MB/s, and then -X67 (UDMA3/ATA48) and upwards makes no difference and on top you get the "not supported" message.


I would like to know what you get and how you get it for what hardware (drive/cable/IDE controler) for any distribution.

Thank you.

[Duh]

works for me. try just using a newer kernel. you can get rpms of the kernels at redhats rawhide ftp site.

[otheos]

Still I find it difficult to accept that in Nov 2001 Redhat released a distribution with a kernel that doesn't support higher than ATA33!

I would love to see some results with other distributions/kernels/devices etc.

[fateswarm]

Have you got that app that checks and switches dma modes? (I don't remember which app it is, anyone?)

It appeared that on Slack, simple "DMA mode" was already set to ULTRA DMA 4 speed.

check that out.

It is very likely that your Linux sets your hard disks to full speed anyway.

[otheos]

You mean hdparm -d1, yes that's there by default.

DMA is enabled (hech it works up to ATA33).

What are your scores?

[subnet_rx]

you think your going to get >60 mbps average throughput with ATA 66?

[otheos]

60mbps (you mean bits or bytes?) cause if it is bits (only 7MB/s so yes I do) if you mean bytes (60MB/s no I don't)

Take the Maxtor DM+ 60, 7200rpm drive. max STR is ~40MB/s, min STR is about 25MB/s, so average is in the 33MB/s range (tested in HDtach/windows).

So even on ATA66 bus the drive performs at max speed (hold the burst but who cares).

However hdparm -t only says 26MB/s which is exactly what a bus limited drive will give. ATA33 may say it can carry 33MB/s but take the overheads and 26MB/s is exactly what you're left with.

I am impressed people seem so unaffected by this. Is everybody using a custom kernel? cause as far as I have tested the stock kernel of RH7.2 does not seem to allow more than ATA33 connections so all the nice HD, cables and fancy ATA66/100 controllers are completely wasted!

[bdg1983]

Here's my Seagate 17GB ATA66

hda: -q -X68 -d1 -u1 -m16 -c3 -A1 -a24 -k1

Timing buffer-cache reads: 128 MB in 0.65 seconds =196.92 MB/sec
Timing buffered disk reads: 64 MB in 4.15 seconds = 15.42 MB/sec

Not that bad I guess.