Tao, - what's the max size of dimensionality? Which data type is used to define dimensionality (ndims)? We assume the max size of dimensionality is relatively small. Hence `int` data type is used to define ndim
- what's the max size of each dimension? Which data type is used to define dimension size (shape[x])? Currently, we assume the max size of each dimension is not going to exceed 2^31 in real applications. Hence the data type is `int32_t` - what's the max size of total elements? Which data type is used to define element size (Prod(shape))? We assume the total number of elements in a tensor can be larger than 2^32 in some applications such as deep graph library. We use the data type `int64_t` to represent the total element size. Currently due to performance regression in some operators (such as transpose), we used a compiler flag to set this data type to `int32_t` by default. Once we have ways to mitigate the performance regression, we will set the default data type to `int64_t`, which is part of the effort in this project that Rohit proposed. What is the plan in MKLDNN to support large tensors? We may want to coordinate the progress since many operators are using MKLDNN implementation in CPU now. Many Thanks, Lin On Sun, Apr 28, 2019 at 7:52 PM Lv, Tao A <tao.a...@intel.com> wrote: > Thank you for bringing this topic to dev, Rohit. > > Regarding large tensor, can you articulate: > - what's the max size of dimensionality? Which data type is used to define > dimensionality (ndims)? > - what's the max size of each dimension? Which data type is used to define > dimension size (shape[x])? > - what's the max size of total elements? Which data type is used to define > element size (Prod(shape))? > > For me, any of these three can be *large*. > > -----Original Message----- > From: Srivastava, Rohit Kumar [mailto:srivastava....@buckeyemail.osu.edu] > Sent: Saturday, April 27, 2019 7:33 AM > To: dev@mxnet.incubator.apache.org > Subject: [RFC] Support for creation of Large Tensors in MXNet > > Dear Community, > > Currently MXNet supports creation of Tensors containing up to 2^32 > elements. However there are cases where tensors of size over 5 billion is > required > > We plan to support creation of large tensors on MXNet. A design proposal > is ready for review: > https://cwiki.apache.org/confluence/display/MXNET/Large+Tensor+Support > > We will appreciate any help and feedbacks from the community. > > Thank you! > > Rohit >
