Yeah I'm pretty sure heat haze in general doesn't need a DX9 capable card. I mean it's just particles with a refraction shader applied right? Refraction was possible even on the Geforce 2. In theory you don't need a DX9 capable card to do *anything*. I mean, ray tracing has been around for a couple decades now. The question is do you want it in real time or not? You can do it in software but it's a lot slower.