How to find HorizSync / VertRefresh rates?

John Murphy freebsd001 at
Mon Apr 30 16:37:15 UTC 2007

Victor Engmark wrote:

>Hi all,
>I'm trying to create a pristine xorg.conf, but I've been unable to
>find proper values for HorizSync and VertRefresh for my Dell Latitude
>I've tried the values presented in MonitorsDB
>for "Dell 1400x1050 Laptop Display Panel", which are HorizSync
>31.5-90.0 and VertRefresh 59.0-75.0, but I get a warning in
>/var/log/Xorg.0.log for both of them saying they are "not within DDC
>I've tried looking around the Dell web pages, but I haven't found any
>pages mentioning these parameters (not too surprising, really).
>I've tried to leave these settings out, but even then I get a warning:
>(WW) I810(0): config file hsync range 60-66.3158kHz not within DDC hsync ranges.
>I'm wondering if this has anything to do with the other warnings I get
>during startup:
>(WW) I810(0): Bad V_BIOS checksum
>(WW) I810(0): Extended BIOS function 0x5f05 failed.
>It seems that a DDC (or, apparently, DDS) query should be able to
>determine these numbers, but
>cd /usr/ports && make search name=ddc && make search name=dds
>doesn't give any tools to deal with this.
>The relevant part of /etc/X11/xorg.conf:
>Section "Monitor"
>  Identifier   "Dell Latitude D610 monitor"
>  VendorName   "SEC"
>  ModelName    "3450"
>  # From Xorg.0.log
>  DisplaySize  286 214
>  Option       "DPMS"

Hi Victor,

Not sure if this will help, but there's some good information from a
Linux Dell D610 user who seems to have a good xorg.conf which should
be roughly the same for FreeBSD:

He mentions a video BIOS patch called '915resolution'. There's a
FreeBSD version at:

More information on "the hack" here:

HTH. John.

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