<br><br><p><DEFANGED_div class="gmail_quote">On Oct 22, 2007 11:05 AM, Justin Denick <<a href="mailto:justin.denick@gmail.com">justin.denick@gmail.com</a>> wrote:<br><blockquote class="gmail_quote" DEFANGED_style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<br> <p><br>Be sure to see what the DMA specs are too.<br><br>hdparm -cuda /devx<br><br>As you can see it makes a big differnece<br><br></p>justin@da-boxx ~ $ sudo hdparm -t /dev/hda<br><br>/dev/hda:
<br> Timing buffered disk reads: 166 MB in 3.02 seconds = 54.92 MB/sec<br>justin@da-boxx ~ $ sudo hdparm -d0 /dev/hda<br><br>/dev/hda:<br> setting using_dma to 0 (off)<br> using_dma = 0 (off)<br>justin@da-boxx ~ $ sudo hdparm -t /dev/hda
<br><br>/dev/hda:<br> Timing buffered disk reads: 18 MB in 3.26 seconds = 5.53 MB/sec<br>justin@da-boxx ~ $ sudo hdparm -d1 /dev/hda<br><br>/dev/hda:<br> setting using_dma to 1 (on)<br> using_dma = 1 (on)<br>justin@da-boxx
~ $ sudo hdparm -t /dev/hda<br><br>/dev/hda:<br> Timing buffered disk reads: 166 MB in 3.02 seconds = 54.88 MB/sec<br>justin@da-boxx ~ $<br><br>It's a kernel option<br>CONFIG_IDEDMA_AUTO=y<p><DEFANGED_div class="Ih2E3d"><br>
</p><DEFANGED_div></blockquote><p><DEFANGED_div><br>hdparm -cuda /dev/x<br><br>only reports for a: "readahead = 256 (on) <br><br>Running "hdparm -d1 /dev/x"<br>result in "HDIO_SET_DEM failed: Invalid argument."<br><br>
The hdparm man page suggest that<br>in rare cases one has to use the -X<br>parameter. It also says this can cause<br>real headaches.<br><br> -Bob<br><br></p><DEFANGED_div></p><DEFANGED_div><br>