50Hz refresh on T42/ATI9600

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Edward Mendelson · #1 Post by **Edward Mendelson** » Sat Feb 10, 2007 2:15 pm

Is anyone else still suffering with the 50Hz refresh rate with ATI drivers for the TP 42 with an ATI 9600 card? If not, does anyone know the solution for this annoying problem? (The flicker is very hard to live with...)

Thanks for any help.

Esben · #2 Post by **Esben** » Tue Feb 13, 2007 1:28 pm

How/what difference do you notice when running 50 Hz compared to 60 Hz? I was under the impression that with flat panels, the refresh rate doesn't make a difference.

I've installed the latest ATI Catalyst Vista drivers, and they don't offer anything but 50 Hz. The limitation might be because of the Plug & Play monitor. If you change it to a standard 1400x1050 flat panel, you might be able to select differently.

Edward Mendelson · #3 Post by **Edward Mendelson** » Tue Feb 13, 2007 1:46 pm

The irritating flicker is very easy to notice (interestingly, the flicker doesn't always occur even though the refresh rate is always listed as 50Hz). There are other posts about the flicker-under-Vista problem, although they're mostly from last year.

zverg · #4 Post by **zverg** » Tue Feb 13, 2007 10:20 pm

LCDs don't flicker.. they can't

Edward Mendelson · #5 Post by **Edward Mendelson** » Tue Feb 13, 2007 10:28 pm

Then *something* is causing the annoying throbbing in the screen. You might want to look at this thread:

http://forum.thinkpads.com/viewtopic.php?t=37079

Apparently, even though (taking your word for it) it's impossible for LCDs to flicker, a lot of us have LCDs that flicker when running Vista.

zverg · #6 Post by **zverg** » Thu Feb 15, 2007 10:46 am

Edward Mendelson wrote:Then *something* is causing the annoying throbbing in the screen. You might want to look at this thread:

http://forum.thinkpads.com/viewtopic.php?t=37079

Apparently, even though (taking your word for it) it's impossible for LCDs to flicker, a lot of us have LCDs that flicker when running Vista.

The flickering of a CRT is caused by using a refresh rate that is low enough that the eye can detect the scanning.. on an LCD, only pixels that have changed are updated, and that is controlled at the most basic, physical level by the nature of an LCD display. If there is any flickering, either the video card is outputting a corrupt video signal or the fluorescent lighting of the screen is faulty. Since it is only happening in Vista, all signs point toward the former.

I have the same video card as you and have been using Vista exclusively on that computer for the past month with no issue. When I get back from work today I can check on what driver version I am using. I know originally I installed the mobile Radeon driver from the ATI web site as Lenovo was not listing a driver on their site yet. I believe I installed the Lenovo ATI driver package when they released it a couple weeks ago.

Does the flickering happen at all screen brightness levels (when plugged in and not)?

Does it happen if you turn off the ATI graphics card power management? To do this, check the Power Options control panel (in the classic control panel view obviously), then click "change plan settings" for the power management profile you are using, then click the link to change advanced settings. There should be an ATI category near the bottom of that list box where you can check on the power management.

The power management of the ATI graphics card driver should only be enabled while powered via the battery, so when plugged in that shouldn't affect anything. I'm just trying to think of any diagnostic angle I would attack this issue from.

Edward Mendelson · #7 Post by **Edward Mendelson** » Thu Feb 15, 2007 11:19 am

Thanks for this - I won't be able to test this until late next week, and I hope others with the same problem might want to look at it in the meantime.

Which Lenovo driver are you using? None was listed for the T42 a few days ago when I last checked.

zverg · #8 Post by **zverg** » Thu Feb 15, 2007 11:41 am

This is the driver I'm probably using.. I'll confirm when I get home from work today:

http://www-307.ibm.com/pc/support/site. ... MIGR-41918

#9 Post by **GomJabbar** » Thu Feb 15, 2007 12:54 pm

This is probably out in left field, but I was wondering what sort of ambient lighting is in use where the "flickering" problem is occurring? Is it fluorescent, incandescent, or natural? Sometimes fluorescent lights can make things appear to be flickering when their frequency of flickering is out of sync with another flickering device, causing a beat or strobe effect.

Also, although zverg contends that LCD's can't flicker (and I am no authority on this), it seems possible to me that slow refresh rate could lead to problems if the capacitors loses enough of their charge before the next refresh cycle.

Wired wrote:Active-matrix displays solve these issues by using switches to regulate the flow of electricity. Each pixel in an active-matrix LCD is controlled by a thin-film transistor (TFT), a very simple switch connected to the pixel's row and column wires. When the switch is triggered, it uses current stored in a capacitor to maintain a steady charge on the pixel during an entire screen-refresh cycle. [bolding added]

With active-matrix displays, we no longer have to worry about pixels fading between refreshes, and that allows the use of liquid crystals with faster response times.

http://www.wired.com/wired/archive/4.01/geek.html

zverg · #10 Post by **zverg** » Thu Feb 15, 2007 1:10 pm

Yeah thanks for digging up an explanation for that. I should have specified that I was talking only about TFT LCDs, but since any ThinkPad powerful enough to run vista has one, I didn't bother

Either way, I'm confident that this is a driver issue as it only happens in Vista.

In XP I believe my refresh rate was also locked to 50Hz, can anyone who still has XP confirm this?

davenet · #11 Post by **davenet** » Thu Feb 15, 2007 1:14 pm

Edward Mendelson wrote:Is anyone else still suffering with the 50Hz refresh rate with ATI drivers for the TP 42 with an ATI 9600 card? If not, does anyone know the solution for this annoying problem? (The flicker is very hard to live with...)

Thanks for any help.

I'm on a T42p with the FireGL driver and I have the same problem. I am anxiously awaiting a driver update form Lenovo or ATI.

David

davenet · #12 Post by **davenet** » Thu Feb 15, 2007 1:16 pm

zverg wrote:Yeah thanks for digging up an explanation for that. I should have specified that I was talking only about TFT LCDs, but since any ThinkPad powerful enough to run vista has one, I didn't bother

Either way, I'm confident that this is a driver issue as it only happens in Vista.

In XP I believe my refresh rate was also locked to 50Hz, can anyone who still has XP confirm this?

I just checked my XP settings and the all the available settings for the display have a 60Hz refresh rate. In the Vista display settings, they are all showing up as 50Hz.

I'm running the FireGL card with 128MB of RAM.

David

Edward Mendelson · #13 Post by **Edward Mendelson** » Thu Feb 15, 2007 2:06 pm

If Chris is using the driver in the link a few messages above, then that's an XP driver. XP drivers apparently work under Vista (I'm using one on my desktop machine), but those of us who are reporting the problem are experiencing it with the Vista driver.

davenet · #14 Post by **davenet** » Thu Feb 15, 2007 2:21 pm

Edward Mendelson wrote:If Chris is using the driver in the link a few messages above, then that's an XP driver. XP drivers apparently work under Vista (I'm using one on my desktop machine), but those of us who are reporting the problem are experiencing it with the Vista driver.

Up to this point I have been looking for a Vista driver, but I also had heard the suggestion to try a XP driver and I may do that if the Vista driver doesn't show up soon.

David

zverg · #15 Post by **zverg** » Thu Feb 15, 2007 2:31 pm

Edward Mendelson wrote:If Chris is using the driver in the link a few messages above, then that's an XP driver. XP drivers apparently work under Vista (I'm using one on my desktop machine), but those of us who are reporting the problem are experiencing it with the Vista driver.

I'm using the ATI branded driver version 8.333.0.0, and the Lenovo page for the XP driver says 8.133.2.1.. Can anyone with the flickering post the version number that you are using and the driver manufacturer?

Edward Mendelson · #16 Post by **Edward Mendelson** » Fri Feb 16, 2007 7:34 am

Why not go to ati.com and download the 32-bit Vista driver for the Mobile Radeon and try it out?

bkhsms · #17 Post by **bkhsms** » Fri Feb 16, 2007 8:38 am

The refresh rate is adjusted through the monitor driver. The main LCD for the T42 uses a generic PnP monitor and as such the refresh rate cannot be adjusted from 50hz. The T42 has a monitor driver located here for XP (nada por Vista):

http://www-307.ibm.com/pc/support/site. ... MIGR-44320

This allows you to adjust the refresh rate in XP which solves most issues with color, flicker and bitmapping.
I've tried both the ATI catalyst drivers and the generic signed driver installed from the Vista install. Neither of these solves the flicker issue. I've since rolled the ATI drivers off and am still running the canned Vista drivers. I've done other such tests as turning off presentation in the mobility center, used all of the resolution and color settings. dicconnected the external display in the event of a power issue splitting the signal between and internal and external adapter, used the port replicator and out of the port replicator, setup the latest ACPI from Lenovo and adjusted to use all of the power profiles. So far the flicker stays in all of the tests.
Anyone else have any good news?

bkhsms · #18 Post by **bkhsms** » Fri Feb 16, 2007 8:45 am

I'm currently using the following adapter driver version:

Windows Vista signed: 8.31.100.321

I was running the ATI catalyst version for the ATI Mobility Radeon 9600:

Catalyst version 7.1

#19 Post by **GomJabbar** » Fri Feb 16, 2007 11:48 am

FWIW, I have a T42 with the ATI Radeon 9000 w/64MB VRAM. I am using the driver that installed with Vista RC1, on RC1. The driver provider is listed as ATI Technologies Inc., driver date 7/31/2006, driver version 6.14.10.6606, and driver signer microsoft windows hardware compatibility publisher. Under display properties, I am running at 60hz. I do not perceive any flickering on my XGA display. I would think this driver would work with the ATI Mobility Radeon 9600, but I am not sure.

I see that ATI has previous Vista drivers listed on the following page, although the version I am using does not seem to be listed.

http://ati.amd.com/support/drivers/vist ... sta32.html

bkhsms · #20 Post by **bkhsms** » Wed Feb 21, 2007 3:49 pm

I opened a support call with Lenovo on the flickering issue and stated my case with loading the ATI drivers and display drivers on to my Vista OS residing on my T42. Their comment was that their engineers are currently working on the 6th generation laptop drivers and that the 4th generation will probably not be addressed. If they will be addressed, then it will be "a long time from now".

DirkM · #21 Post by **DirkM** » Thu Feb 22, 2007 10:13 am

I got mixed results when testing Vista RTM on a T42 with ATI 9600. Out of the box it uses the Microsoft WDDM driver which supports Aero. But then, once in a while, the screen flickers. And it's not the typical CRT flickering, it more like the backlight flickers. I wasn't able to cause that on purpose, it comes and goes.

I also tried to use the XP driver from Lenovo but besides getting a couple BSOD I also lost Aero with that driver. So I went back to the WDDM driver hoping that Lenovo will eventually release a working driver for the ATI 9600.

bkhsms · #22 Post by **bkhsms** » Thu Feb 22, 2007 10:25 am

Yes, I've noticed the issue occurs infrequently. It is the lighting of the screen that is flickering on my T42. Most noticeable on the outer edges of the LCD, but occurs on the entire screen. I went back to the ATI catalyst drivers and it seems to occur less often now. Strangely enough when I put the laptop in hibernate and bring it out of hibernate 3:4 times the issue is corrected. Kind of like holding the wire hanger while grabbing the back of the TV and standing on my left leg clears up the reception.

ron1n · #23 Post by **ron1n** » Tue Mar 06, 2007 10:30 pm

I am suffering this issue as well on my T41p with the ATI Mobility FireGL T2 card. I have pretty much tried everything but it dosent help, stuck to 50hz. The funny thing is on XP the refresh rate is 60hz so I am wondering if I upgrade instead of fresh install then will vista keep the 60hz refresh rate ?

bkhsms · #24 Post by **bkhsms** » Wed Mar 07, 2007 7:51 am

I've not tried an upgrade yet, but when you upgrade the same display driver will be installed. The settings for the generic display driver will more than likely be the same as a fresh install.

byunnbi · #25 Post by **byunnbi** » Tue Mar 13, 2007 12:37 am

I'm not sure if this will help any of you -

I have a t41p (128mb FireGL T2) and have not had this flickering issue, but I did want to add that when I display my TP out of my Dell 2001FP, the refresh rate is automatically 60hz while displaying from my TP LCD has always been 50hz under Vista (Vista Ultimate, btw). I remember trying to get the 50hz back up to 60hz and had no success either with any drivers.

50Hz refresh on T42/ATI9600

50Hz refresh on T42/ATI9600

Re: 50Hz refresh on T42/ATI9600

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