Hi!
I am trying to implement quantization in my model.
In the case of Post Static Quantization some interesting detail came across:
quantized_model.qconfig = torch.quantization.get_default_qconfig('qnnpack')
# torch.backends.quantized.engine = 'qnnpack' # gives error

works nearly perfect according to performance numbers. However, qnnpack is not available as an engine on my machine.
Trying to use
quantized_model.qconfig = torch.quantization.get_default_qconfig('fbgemm')

led to much worser performance numbers.
Also, in my opinion this should not work, but does perform very good:
quantized_model.qconfig = torch.quantization.get_default_qconfig('qnnpack') 
torch.backends.quantized.engine = 'fbgemm'

Is this a bug? Shouldn’t fbgemm outperform qnnpack an a x86 system?