GDAL won't run on GPU with CUDA or OpenCL, forced to CPU

I’m running mint 17.1 and have installed the CUDA 6.5 toolkit. I have also gotten the sample CUDA tests to run just fine on a Quadro K420 and am running an SSD for storage for the time being.
I’m running into trouble when trying to run gdalwarp to reproject georeferenced jp2 images.
the proccess is running on the CPU rather than the GPU.

I have compiled GDAL from source with OpenCL support along with the other libraries needed for compatibility with my data sets.

I’m running the gdalwarp command as follows:
time gdalwarp -tr 1 1 -t_srs ‘+proj=merc +a=635752.3142 +b=634752.3142 +lat_ts=0.0 +Lon_0=0.0 +x=0.00 +y_0=0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs’ -r cubic -of gtiff -wm 6000 -multi -wo “NUM_THREADS=ALL_CPUS” sourceImg.jp2 testOut.tif

I have played around with the -multi and -wo switches but they don’t make any difference in processing time.

Any help would greatly be appreciated.

I hav now compiled the nvidia opencl sample code and it seems to be running fine but I still can’t compile gdal in a way that allow it to make use of opencl.

are there nvidia specific opencl libraries that gdal should b compiled with?