Tearing artifacts when displaying stimuli for single refresh rates


We recently purchased a new laptop specifically for running priming studies by presenting stimuli for single refresh rates (1/60th second on a 60hz LCD). Laptop specs are below. 

We tested presentation times on a number of our laptops (older dell latitudes, and some intel macbooks) using an oscilloscope and a photo diode. Superlab is capable of displaying single refresh rates consistently on the PC laptops and less so on the mac laptops (and completely fails on brand new Imacs). It also works great on our new Dell Studio laptop, however the images demonstrate a sort of tearing artifact (entire lines, and even horizontal blocks are missing). It's almost as though a CRT was skipping a bunch of scanlines. However, we're only using LCDs.

This artifact is replicated on both the laptop native LCD monitor and a pair of external LCD monitors.

The only big difference that we can see between this laptop and our working (but old) dell Latitudes is that this one is using Windows Vista.

 Is anyone aware of problems with single refresh rate presentation times in Vista? The laptop is damn near top of the line, so I'm surprised that it's causing problems when our 5 year old latitudes have no trouble presenting single refresh rate images without artifacts using on board video, while this laptop has a dedicated video card.

Laptop Spec:
Dell Studio 17"
Intel Core 2 Duo
4Gigs of ram
Radeon 3650 video card

In case anyone is watching this thread, installing Windows XP fixed the problem. Single refresh rate presentations of images no longer tear as they did in Windows Vista.

However, it would be great if this could be fixed for Vista or Windows 7. Finding drivers for new Dell laptops for Windows XP was tricky to say the least since Dell no longer support XP and some of the new hardware simply doesn’t have XP drivers.

Is anyone else trying to do priming studies (single refresh rate / 17ms displays) on Vista running into this problem?


Replying to myself, but just in case this helps someone else.

Vista was not the problem. The bundled Dell drivers for the radeon HD3650 were garbage. Used desktop radeon HD3650 drivers hacked to run on mobile cards and the tearing artifact is gone in Vista.

Instructions were found here: http://www.driverheaven.net/modtool.php

Worked like a charm.