Using an actual fan to cool your GPU

I know this sounds like a crazy idea, but I'm still curious.

Topaz is all about getting the most out of your GPU. On a whim, I placed an externally powered mini desktop fan at the air intake by my GPU. Interestingly, I saw a constant 1-2 degree decrease in GPU temperature during Topaz processing.

1-2 degrees doesn't make a difference, but again, this was from a mini desktop fan. So now I'm curious whether a larger fan would make a difference that could impact performance. This is of course on a desktop, not a laptop, where such a fan would directly interact with the internal airflow.

Has anyone tried this?

*edit*

I experimented with a couple Topaz projects using the "opening up the case and blasting the fan right into it" approach. I kept the case on the side so I could easily emulate the airflow with it on, and took readings with the fan in various locations.

I got an interesting result:

The GPU temperature didn't change much (still stayed above 70C), but interestingly, the GPU utilization was at 100% or consistently closer to it for much longer. Looking at the "time remaining", this translated to a roughly 15% decrease in the time it takes to render the job. Just to be sure, I checked the remaining time at multiple intervals with the fan in different locations/case cover on/off.

I'm not 100% certain if Topaz is made to push the GPU if it sees the temperature is at acceptable ranges, but that would be one way to interpret the results. I'd have to do more experiments to be sure, but if this is a stable result, it could be worth using as "speed boost" for particularly onerous jobs. I'm hesitant to use it for every job because there will definitely be more debris accumulation without the case cover. But there does seem to be a discernable effect.