Hello Andreas, On Mon, Jul 4, 2011 at 2:23 AM, Andreas Kloeckner <lists(a)informa.tiker.net&gt; wrote: >> I think this issue might be related to how float4 arguments are >> passed >> to kernels? > Nope. When passing arrays, you need to say array.data. Thanks, it works now! Maybe passing an array type as kernel argument is a common enough newbie-misuse that warrants a more explicit error message?