What is the memory consumption of cufft?

Accelerated Computing CUDA CUDA Programming and Performance
1

I need to know what’s the peak memory consumption of cufft.
given:
cufftPlan1d(&plan, N, CUFFT_C2C, M) ;

and
cufftExecC2C(plan, data, data, CUFFT_FORWARD) ;
or
cufftExecC2C(plan, data, data, CUFFT_BACKWARD) ;

?

(the fft’s complexity is probaby O(Nlog(N)) but is that also the peak memory consumption? in that case is the peak memory consumption equal to MN*log(N)*sizeof(float)?)

Thanks!

Y.