mobilenet is not fast

[Rookielike]

thanks for your code.
when i replace resnet with mobilenet,i find the speed of model is slower..
i'm so confused . i run model in GPU(titan X)
do you know the reason?
the following is my code:

def conv_dw(in_channels, out_channels, kernel_size=3, padding=1, stride=1, dilation=1):
return nn.Sequential(
nn.Conv2d(in_channels, in_channels, kernel_size, stride, padding, dilation=dilation, groups=in_channels, bias=False),
nn.BatchNorm2d(in_channels),
nn.ReLU(inplace=True),

    nn.Conv2d(in_channels, out_channels, 1, 1, 0, bias=False),
    nn.BatchNorm2d(out_channels),
    nn.ReLU(inplace=True),
)