How to find HorizSync / VertRefresh rates?

Victor Engmark victor.engmark at
Mon Apr 30 16:50:29 UTC 2007

On 4/30/07, John Murphy <freebsd001 at> wrote:
> Victor Engmark wrote:
> >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
> >D610.
> >
> >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
> >ranges."
> >
> >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
> >and
> >(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"
> >EndSection
> 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:

The xorg.conf there doesn't define HorizSync or VertRefresh.

He mentions a video BIOS patch called '915resolution'. There's a
> FreeBSD version at:
> More information on "the hack" here:

I'm already using this. It's listed at the end of my email. In case my
message was unclear, I've already managed to get the native resolution. I'm
only looking for the proper HorizSync / VertRefresh rates, to avoid frying
my graphics card or screen, and to get the maximum out of my hardware at the
same time. I've already tried rates from several articles, but all of them
result in warnings that the rates are outside the DDC spec, and none of them
document where the numbers are from. The only reference I've found so far,
MonitorsDB, is wrong, and Dell doesn't list the information I need.

Victor Engmark
Quidquid latine dictum sit, altum videtur - What is said in Latin, sounds

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