I want to used theano with GPU ,but it seemed that GPU is not worked?

Question

I want to use theano with GPU ,and I use the following script to test if GPU is working:

import os    
os.environ['THEANO_FLAGS'] = "device=gpu0"    
import theano
from theano import function, config, shared, tensor
import numpy
import time

vlen = 10 * 30 * 768  # 10 x #cores x # threads per core
iters = 1000

rng = numpy.random.RandomState(22)
x = shared(numpy.asarray(rng.rand(vlen), config.floatX))
f = function([], tensor.exp(x))
print(f.maker.fgraph.toposort())
t0 = time.time()
for i in range(iters):
    r = f()
t1 = time.time()
print("Looping %d times took %f seconds" % (iters, t1 - t0))
print("Result is %s" % (r,))
if numpy.any([isinstance(x.op, tensor.Elemwise) and
              ('Gpu' not in type(x.op).__name__)
              for x in f.maker.fgraph.toposort()]):
    print('Used the cpu')
else:
    print('Used the gpu')

but I get the following result:

WARNING (theano.sandbox.cuda): The cuda backend is deprecated and will be removed in the next release (v0.10).  Please switch to the gpuarray backend. You can get more information about how to switch at this URL:
 https://github.com/Theano/Theano/wiki/Converting-to-the-new-gpu-back-end%28gpuarray%29

/usr/lib/python2.7/site-packages/theano/sandbox/cuda/__init__.py:556: UserWarning: Theano flag device=gpu* (old gpu back-end) only support floatX=float32. You have floatX=float64. Use the new gpu back-end with device=cuda* for that value of floatX.
  warnings.warn(msg)
Using gpu device 0: GeForce GT 720 (CNMeM is enabled with initial size: 50.0% of memory, cuDNN 6021)
/usr/lib/python2.7/site-packages/theano/sandbox/cuda/__init__.py:631: UserWarning: Your cuDNN version is more recent than the one Theano officially supports. If you see any problems, try updating Theano or downgrading cuDNN to version 5.1.
  warnings.warn(warn)

[Elemwise{exp,no_inplace}(<TensorType(float64, vector)>)]
Looping 1000 times took 3.424644 seconds
Result is [ 1.23178032  1.61879341  1.52278065 ...,  2.20771815  2.29967753
  1.62323285]
Used the cpu

My Question What does the result mean? and How do I make it work to use the GPU?

Answer 1

I had similar issue with new version of theano. You can try with

THEANO_FLAGS="floatX=float32,device=gpu,nvcc.flags=-D_FORCE_INLINES" python test_gpu.py