Restrict app downloads by device model

[Gabito]

Hi there!

I made a CPU intensive application that runs failrly well on certain devices (iPod Touch 2G+, iPhone 3G+), but performs really bad on the slower ones.

So I would like to restrict which people can download my application from the App Store, based on the device model (CPU speed), rather than by its capabilities (which can be done using the UIRequiredDeviceCapabilities property).

Is there any way to do that? If it can't be done directly, do you know of any workaround?

Thanks in advance!
Gabito.