In message <[EMAIL PROTECTED]>, "James R. Van Artsdalen" writes:
>A Sandisk Ducati 4GB CF is installed. Sandisk claims 45 MB/s reads (and >writes!). I'm seeing about 26 MB/s using dd bs=64k. The verbose kernel >output from FreeBSD's boot implies that the CF socket is emulating a >40-pin cable so UDMA33 is used instead of UDMA66. Do normal CF sockets >require UDMA33 in spite of the short "cable length" or is this perhaps a >Soekris motherboard issue? I'm not quite sure what the exact terminology is, I think it may be half-way deliberate choice on Sørens part. The ata bus runs to the SATA bridge-chip, the 44 pin connector, the CF socket and the pads for solder-on CF flash on the board (I don't know in which order). I've tried patching a kernel to force UDMA66 mode, and I do see sporadic UDMA errors when I do so, both on PATA, SATA and CF cards. In practice, the difference between UDMA33 and UDMA66 isn't that big, since the CF-cards only can keep that sort of speed up for sequential reads/writes in the first place (ie: camera use pattern). A patch was committed to FreeBSD -current recently which makes it possibel to force 80-wire cable but I'm not aware if this has been MFC'ed to 7.x yet. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.
_______________________________________________ Soekris-tech mailing list [email protected] http://lists.soekris.com/mailman/listinfo/soekris-tech
