Does GDALWARP have support for OpenCL speedup to orthorectification?

Question

So I am attempting to orthorectify some images very large images. The process can take several hours so currently I am relying on using 8 threads to perform the speed up. However, the GPU does not appear to be in use at all according to nvidia-smi. I am very confused why this is the case:

Here is the script I am using:

#! /bin/sh

CUR_DIR="$(cd $(dirname ${BASH_SOURCE[0]}); pwd)"
export LD_LIBRARY_PATH="$CUR_DIR/../lib"
$CUR_DIR/gdalwarp -overwrite -rpc -to RPC_DEM="$1" -wo USE_OPENCL=TRUE   "$2" "$3"

I am attempting to orthorectify a large NITF which have I stored into an RPC model:

I have copied the different bands from GDAL info to see if I need to change the -wt or -ot to speed up the computation. I have recompiled GDAL with Nvidia's OPENCL and am running that recompiled version.

Why does GDALWARP not use the GPU in this case?

Band 1 Block=128x128 Type=UInt16, ColorInterp=Blue
  Mask Flags: PER_DATASET ALPHA 
Band 2 Block=128x128 Type=UInt16, ColorInterp=Green
  Mask Flags: PER_DATASET ALPHA 
Band 3 Block=128x128 Type=UInt16, ColorInterp=Red
  Mask Flags: PER_DATASET ALPHA 
Band 4 Block=128x128 Type=UInt16, ColorInterp=Alpha

Answer 1

Unfortunately, it turns out at this time, GDAL does NOT support OPENCL speed up on orthorectification. In fact, the only speedup I have been able to find is that compiling with OpenCL does speed up resampling slightly. This would be a good feature for GDAL to implement at a future date.