我想将theano与GPU一起使用，但似乎GPU不起作用？答案

【问题标题】：I want to used theano with GPU ,but it seemed that GPU is not worked?我想将theano与GPU一起使用，但似乎GPU不起作用？
【发布时间】：2017-05-10 02:13:42
【问题描述】：

我想将 theano 与 GPU 一起使用，我使用以下脚本来测试 GPU 是否正常工作：

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')

但我得到以下结果：

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

我的问题 结果是什么意思？以及如何使用 GPU？

【问题讨论】：

标签： gpu theano theano-cuda

【解决方案1】：

我对新版本的 theano 也有类似的问题。你可以试试

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

【讨论】：