iMac with ATI HD 2400: Strange moir

[TOMillr]

Hi folks,

i'm currently using a 64-bit version of Windows 7 RC on an iMac with a build in ATI Radeon HD 2400 video card. But I've noticed that the display has a strange moir?-like effect (picture looks "instable", like the surface of disturbed water), that is not present under MacOS 10.5. Any ideas what is causing the iMac display to look so different when running Windows? Is there a dedicated iMac display driver for this hardware that might change this?

Thanks,

TOM

EDIT: Forgot to mention that I'm using the latest 9.5 beta drivers from ATI. Also, the effect can be best seen on areas like the blue/gray tab area of IE8.

EDIT2: Been toying around with those ATI drivers and I've justed noticed something strange. When I install the newest drivers, the screen goes black for a second before the install routine is done and after that the moir? distortion is completely gone - but just to come back the moment I restart the system or logon to a different user...

Edited June 3, 2009 by CrazyLexx

[TOMillr]

No guesses why the distortions are gone directly after the ATI drivers are installed and why the come back after a system reboot?

[+Frank B. Subscriber²]

I'm having the same effect on an early 2008 20" iMac running Win7 x86. It's one of those small annoyances which don't bug me that much and likely boil down to the beta status of the drivers... here's hoping it will be resolved come Win7 RTM and a final version of the ATI drivers.

[TOMillr]

Just updated to the new 9.6 drivers from ATI and those distortions are still there. :wacko:

[Guest]

Unfortunately I have been experiencing the same problem with my late 2008 20" iMac (ATi Radeon HD 2600 PRO). It happens in Windows XP, Vista & 7 for me. It's a well known problem, see the following threads:

http://forums.macrumors.com/showthread.php?p=7138888

http://www.mac-forums.com/forums/windows-c...lease-help.html

http://discussions.apple.com/thread.jspa?messageID=9412047

https://www.neowin.net/forum/index.php?show...=678232

Its very annoying when you are working on something like a website.

Edited June 20, 2009 by Guest

[StevoJD]

Well I'm another sufferer of this problem. It could either be a driver or firmware problem, because when updating the drivers it's not that noticeable anymore unless you're staring at a grey background. Still annoying nonetheless though, but yeah I've tried everything and googled for hours and no fix for me or anyone else.

[TOMillr]

Its very annoying when you are working on something like a website.

Right, and it hurts my eyes when I'm textediting for a longer period.

Well I'm another sufferer of this problem. It could either be a driver or firmware problem, because when updating the drivers it's not that noticeable anymore unless you're staring at a grey background.

Yep, that's the point I don't get - why is there this marked difference right after installing a driver. And why does it come back after a reboot?

[Guest]

I'm hoping that when Snow Leopard comes out it has a fix to resolve the issue. Hope its a problem with bootcamp or firmware/drivers, and not the screen, though I don't think it is because it's not appearing in OS X.

[StevoJD]

Nah I don't think it's the screen. It's most likely a driver problem of some sort where the screen isn't properly calibrated resulting in the "effect" that we've learned to love...

If it were a video card problem then the problem would also effect my dual display, which it doesn't. ;)

Anyways it's Apple, hate it or love it their hardware will always have some sort of minor annoying problem...

[Phantom Helix]

If you guys make sure your AFI firmware is up to date and PLEASE use the Apple provided boot camp drivers and do not update them with Manufacturer drivers as they do not include some things needed.

You have to understand that Windows Running in Boot camp on a Mac has special needs that GPU makers do not include in the general Public Driver installers.

I have seen this issue occur on a friends iMac and we updated his EFI firmware and installed the proper Boot Camp driver set and it fixed it

( you can use the Vista 32 or 64 set for Windows 7 just fine, although you may have to download an earlier set than 2.1 because it may tell you it is not supported on your Mac, then you can use the 2.1 updater like normal on 64bit Windows )

[StevoJD]

My EFI firmware is up-to-date with 1.3 on my iMac, and I even tried using the Boot Camp drivers and with them it looks the worst.

[Chasethebase Veteran]

I have noticed this before on my HP w1907v monitor (Rarely though), all I'd do is turn the monitor off and back on and it'd fix the issue. It seems a bit deeper than that here with the iMac, as well as you can't turn the screen off like a regular monitor? (I'm not the most knowledgeable person on Macs in the world).

[Guest]

My EFI firmware is also up-to-date on my iMac, and i've also tried using the bootcamp drivers.

[+Frank B. Subscriber²]

Like Chris before me I hope for a fix coming with OS X 10.6 and Boot Camp 3.0, which should come with Windows 7-specific drivers.

[Ambroos]

I always get Moir? on my screen when using the wrong refresh rate. Try playing with that a little?

[+Frank B. Subscriber²]

I always get Moir? on my screen when using the wrong refresh rate. Try playing with that a little?

Tried, didn't help any.

[TOMillr]

Just to keep this thread going: Using the lattest, non-beta drivers from ATI still doesn't get rid of those wavy lines. :angry:

[+Frank B. Subscriber²]

There was an updated driver for the ATI Mobility Radeon 2400 XT on Windows Update which seems to have fixed the Moir? issue.

Version:

[Snakehn]

There was an updated driver for the ATI Mobility Radeon 2400 XT on Windows Update which seems to have fixed the Moir? issue.

Version:

that's weird, that update didn't pop up in here, still using an older one

edit: Weird, windows update didn't show anything, but i went to the video card properties and updated from there and found a new driver, the one i was using was from January 09, then it found one from april 09, after that, i ran windows update and found that same driver you are using, but after i restarted the computer, that Moir? issue is bac:(::(:(

Edited August 29, 2009 by Snakehn

[mitnadev]

I have same problem. How to solve it?

[TOMillr]

but after i restarted the computer, that Moir? issue is back:((:((

This is what happens every time I install a new version of the ati drivers on my MBP: At the end of the install process the screen goes black for a second and when the picture comes back all those distorations are gone - just to come back after a reboot or a user change.

This is really driving me crazy because it shows just how stable and calm the system could run on this computer if only we could this stupid problem fixed. It's obviously just a setting or driver issue since it CAN work properly at times.

[daam]

Any new information yet? I still expierence the same problem, but it looks like i have to deal with it.

Anyway if somebody has a solution or suggestion please inform us.

thx

[TOMillr]

Nope, just started from scratch with a clean install of the final Windows 7 version and the latest BootCamp divers but those line are still present.

But there's got to be a way to fix this, because the screen CAN by stable and without lines right after installing a new driver when the screen goes black and is reset. Maybe it is just some strange faulty setting? A refreash issue with the monitor perhaps?