If I am reading that correctly, each input to 3dDeconvolve should be about 6 GB (if you uncompressed a .gz file). Since you have 6 runs, that is 36 GB just to hold the input, plus at least another 36 GB for processing and output. You would need between 70 and 100 GB of RAM to process it.
Your computer has 15 GB of RAM, which is not remotely close.
Are the voxels originally 1mm in size? Is this 7T data?
Or perhaps is it partial coverage at a high resolution, which blows up to a big volume? The original BRIK files are not so big.
- rick