KVM refuses to allow >60 Hz refresh rate ... even though Windowsthinks it is

[bruce]

Here's an interesting question. I have an ATI 9600XT and a NEC Multisync
FE950+ monitor, running under Windows 98SE.

I can configure 75 Hz if I direct-connect the video card to the monitor.
No problem. (I've downloaded the INF file so that the monitor is
properly recognized as an NEC MultiSync FE950+ rather than a
Plug-And-Play monitor, i.e. Windows knows exactly what refresh rates
are supported, and isn't relying on the DDC signal from the
monitor to find out)


However, I just bought a D-Link DKVM-2K KVM switch and I only get 60 Hz
at 1152 x 864 now. Sometimes.

I can use Windows Display Properties to tell the 9600XT to output
1152 x 864 x 85 Hz, but only 60 Hz shows up at the monitor (as
proved by painful flickering, and the NEC's on screen display).
If I exit Display Properties and come back in, I can confirm that
Windows believes it is truly outputing 85 Hz.

However, if I now directly connect the 9600XT to the monitor
(no KVM), only 60 Hz results. So the 9600XT thinks it's putting
out 85 Hz but it's only 60Hz. In other words, it's NOT the
KVM switch that degrades the signal.

Rather, the KVM switch seems to be blocking the signal and
preventing the initial setup of 75 Hz.



The only workaround I could come up with sucks. It's to boot up
with the 9600XT directly connected to the monitor. 75 Hz is okay
in that case. Then I unplug the monitor cable and hook it up
through the KVM. In this case, the video card keeps pumping out
a 75 Hz signal, and the monitor keeps displaying a 75 Hz signal.

But all this plugging and unplugging kind of defeats the purpose
of having a KVM switch!



So ... is this a problem with the ATI drivers where it relies
on some signal back from the monitor, which the KVM is blocking?


Any advice would be appreciated. Thanks --

Bruce

 

[Kev]

I've got the integrated KVM from Linksys and found this out:

The computer needs to see the monitor when Windows boots up otherwise
Win will not see any monitor and thus 60hz. Not bad for flat screens but
lousy for crt's.

So make sure the KVM is set to what ever computer is booting up then
switch over.

In XP the welcome screen is the refresh of Windows.

 

[Mike]

Dumb question. Did you do the video setup with the NEC ini file without
the KVM connected. Monitor the PC. Then put the KVM in place.
I have a Belkin KVM with a NEC FE950 and a keyboard plugged in. I use
a separate mouse on each PC. I have no problems. One PC is a PIII
with video at 1152x864 75Hz and the other is a PIV at 1280x1024 75Hz.
I can boost that one to 85Hz with more res. The only issue is once
in a great while, when I start to PIV, the monitor doesn't get the
signal.

 

[bruce]

Dumb question. Did you do the video setup with the NEC ini file without
the KVM connected. Monitor the PC. Then put the KVM in place.
I have a Belkin KVM with a NEC FE950 and a keyboard plugged in. I use
a separate mouse on each PC. I have no problems. One PC is a PIII
with video at 1152x864 75Hz and the other is a PIV at 1280x1024 75Hz.
I can boost that one to 85Hz with more res. The only issue is once
in a great while, when I start to PIV, the monitor doesn't get the
signal.

Dumb questions lead to smart answers - I re-did the monitor setup
without the KVM connected (switched from NEC FE950+ to generic
SVGA 1280x1024x75 Hz monitor) and then hooked up the KVM. Now I
can switch back and forth between 60 Hz and 75 Hz with no problem!

(To double-check, I tried to change the monitor definition
with the KVM in place, and sure enough, I was back to 60 Hz)

So your suggestion was exactly right. Thanks! I owe you a beer
in the name of dumb questions.

Bruce

 

[bruce]

One last follow-up, because it looks like the problem is
a little more subtle than I had thought.

If I install the ATI Control Panel software, I can't
change refresh rates with the KVM inline - the refresh
rate instantly locks on to 60 Hz. It looks like the ATI
"Display" tab overrides Win98SE's Display Properties,
determines that the monitor can only run at 60 Hz, and
forces that mode.

After uninstalling ATI Control Panel, I can switch refresh
rates with no problems ...

Anyway, thought I'd post this for the benefit of KVM users
searching Google Groups in the future.


Bruce

 

[Mike]

I'm glad it works, but it does sound a bit odd on the final outcome.
The cards that I switch between are; on the PIII an ATI Rage Fury Pro
and on the PIV an ATI AIW 9000Pro. I run Win XP on both and SP1 with
most of the updates on the PIV. I also use Catalyst 4.4 with MMC9.0.
I just checked the frequency. It is at 75Hz and I just changed it to
85Hz and back to 75Hz with no problem. I have heard of issues with
Catalyst above 3.7 in some cases. The message Kev sent has a good
point also, I have to make sure the KVM is locked in to the PC to boot
or I may not get video.

 

[borolad]

Here's an interesting question. I have an ATI 9600XT and a NEC Multisync
FE950+ monitor, running under Windows 98SE.

I can configure 75 Hz if I direct-connect the video card to the monitor.
No problem. (I've downloaded the INF file so that the monitor is
properly recognized as an NEC MultiSync FE950+ rather than a
Plug-And-Play monitor, i.e. Windows knows exactly what refresh rates
are supported, and isn't relying on the DDC signal from the
monitor to find out)


However, I just bought a D-Link DKVM-2K KVM switch and I only get 60 Hz
at 1152 x 864 now. Sometimes.

I can use Windows Display Properties to tell the 9600XT to output
1152 x 864 x 85 Hz, but only 60 Hz shows up at the monitor (as
proved by painful flickering, and the NEC's on screen display).
If I exit Display Properties and come back in, I can confirm that
Windows believes it is truly outputing 85 Hz.

However, if I now directly connect the 9600XT to the monitor
(no KVM), only 60 Hz results. So the 9600XT thinks it's putting
out 85 Hz but it's only 60Hz. In other words, it's NOT the
KVM switch that degrades the signal.

Rather, the KVM switch seems to be blocking the signal and
preventing the initial setup of 75 Hz.



The only workaround I could come up with sucks. It's to boot up
with the 9600XT directly connected to the monitor. 75 Hz is okay
in that case. Then I unplug the monitor cable and hook it up
through the KVM. In this case, the video card keeps pumping out
a 75 Hz signal, and the monitor keeps displaying a 75 Hz signal.

But all this plugging and unplugging kind of defeats the purpose
of having a KVM switch!



So ... is this a problem with the ATI drivers where it relies
on some signal back from the monitor, which the KVM is blocking?


Any advice would be appreciated. Thanks --

Bruce

Quote : -

PROBLEMS WITH XP REFRESH RATES

This problem is about WinXP not applying the refresh rates and is
always stuck at 60Hz no matter which resolution or Refresh rate you
choose. This is how to fix it:

1- Make sure you monitor is identified as Plug & Play or WinXP is
using your Monitor driver.

2- Right Click an empty space in your desktop and click PROPERTIES, in
the display properties, click the followings: SETTINGS, ADVANCED,
DISPLAYS, MONITOR. On monitor attributes, you will see that "USE DDC
INFORMATION" is marked, and you will also see that the maximum
resolution and refresh rate for your monitor are selected. Uncheck
"USE DDC INFORMATION" and press APPLY. Now you can select ANY refresh
rate supported by your monitor.

If the control "USE DDC INFORMATION" is grayed out, here's a fix:

1- Download and install the latest PowerStrip.
2- Run it, it should Autodetect the problem and fix it automatically.
3- Close and uninstall PowerStrip (if you desire)
4- Restart your PC.

When you return to XP the monitor controls should be enabled.

There are two BAD things you should know:
1- OpenGL games STILL have the refresh rate problem. (they will
default to 60Hz)

2- Your currently selected desktop refresh rate will be used for ALL
your games, no matter which resolution you use in the game. Ex. If you
choose a desktop setting of 1024x768x32@75Hz then any game, even
running at 800x600 or 640x480 will run at 75Hz.

I hope one day MICROSOFT fixes this BUG and make the
resolution+refresh rate system just like the one used in Win9x, where
each resolution had it's own refresh rate setting and games run
accordingly with it.

Un-Quote, goto Ati help here :

http://www.omegacorner.com/index_ati.html


BoroLad

 

[chuckk]

You found the cigar! The later monitors and LCDs send a block of
information to the video card and driver, listing the the monitor ID and
capabilities. The Belkin somehow blocks the information. So, windows assumes
that the monitor was changeed from whatever the monitor reported to a
generic monitor.
Evidently Several of the ATI drivers do the same thing independent of the
windows internal operations. To get around the problem, I generally set
windows and the drivers as appropriate to allow all resolutions
combinations. Another way is to find an inf file or the equivilent that
defines a monitor that has similar characteristics and does not send the
capability info to the video card and driver. This works well with older
versions of windows. I haven't tested it with XP. Some games allow you to
set both resolution and refresh rate regardless of the display sennings at
the game start.A few of the older ones don't reset the display properly (or
in a compatable manner with the current windows reset scheme).

 

[bruce]

One last follow-up, because it looks like the problem is
a little more subtle than I had thought.

If I install the ATI Control Panel software, I can't
change refresh rates with the KVM inline - the refresh
rate instantly locks on to 60 Hz. It looks like the ATI
"Display" tab overrides Win98SE's Display Properties,
determines that the monitor can only run at 60 Hz, and
forces that mode.

After uninstalling ATI Control Panel, I can switch refresh
rates with no problems ...

Anyway, thought I'd post this for the benefit of KVM users
searching Google Groups in the future.

Argh. Next time I'm going to wait a week and totally understand
the issue before posting. After one or two reboots the
"solution" didn't work any more. Now I'm relying on PowerStrip
to take care of the refresh rate. So far it seems to work ...

Bruce

 

[Mike]

Here's an interesting question. I have an ATI 9600XT and a NEC Multisync
FE950+ monitor, running under Windows 98SE.

I can configure 75 Hz if I direct-connect the video card to the monitor.
No problem. (I've downloaded the INF file so that the monitor is
properly recognized as an NEC MultiSync FE950+ rather than a
Plug-And-Play monitor, i.e. Windows knows exactly what refresh rates
are supported, and isn't relying on the DDC signal from the
monitor to find out)


However, I just bought a D-Link DKVM-2K KVM switch and I only get 60 Hz
at 1152 x 864 now. Sometimes.

I don't like trouble making components, I would just return the Dlink
and get a Belkin, which works just fine for me (using 98se and xp
pro).

 

[Kev]

However, I just bought a D-Link DKVM-2K KVM switch and I only get 60 Hz
It's like i said. Boot into windows so that the computer sees the
monitor than switch over.

 

[PhxGrunge]

The KVM does not pass the DCC info to the video card. You must turn off DCC
in display properties to stop Windows from looking for the signal. As long
as DCC is set to on, and Windows does not see the signal, Windows will
always revert to 60 Hz refresh. That's why when you direct connect monitor
to video card, refresh is right, but remove the signal thru the KVM, and
windows reverts to 60 Hz.

 

[Bruce Lin]

The KVM does not pass the DCC info to the video card. You must turn off DCC
in display properties to stop Windows from looking for the signal. As long
as DCC is set to on, and Windows does not see the signal, Windows will
always revert to 60 Hz refresh. That's why when you direct connect monitor
to video card, refresh is right, but remove the signal thru the KVM, and
windows reverts to 60 Hz.

Where is this setting? As I understand it, Windows XP has a specific
setting where it says "use DDC settings" However, in Windows 98SE,
which I run, there's no such choice. I can__ define the monitor type
as something like "Generic Super VGA 1024 x 768" (which I understand
it should not look for DDC information) instead of "Plug and Play
monitor" (which should look for DDC information).

However, even with the Generic monitor setting, and it still falls
back to 60 Hz upon bootup.

I think it's actually the ATI drivers which force the video card back
to 60 Hz.

Bruce

 

[PhxGrunge]

In Windows 9x, display properties, advanced, monitor tab. Uncheck "Monitor
is Energt Star compliant" and "Automatically detect Plug & Play monitors".
This should stop Windows from using the DCC info. If not, then the inf file
for the monitor must be edited so that DCC=0(or false).

 

[bruce]

Okay, got it. Basically PhxGrunge was correct.

In WinXP apparently there is an option to ignore the DDC
signal. In Win98, the ATI drivers have this idiotic registry
setting called

"IDCRegOptionDontUseOSMonitorInfo" = hex 01,00,00,00

which overrides whatever Win98 has configured under Display
Properties. Changing the values to 00,00,00,00 (i.e.
Use OS Monitor Info) and then rebooting fixed things.

Uninstalling the Catalyst control panel turned out to be a
wild goose chase.

Anyway, thanks to all those people who had this ATI driver
problem in the past who posted their solutions on Google
Groups. And thanks to everyone here who offered suggestions
and insight.

Let this is my last post on the subject ...

Bruce