[mvapich-discuss] Difference between MVAPICH2 and MVAPICH2-GDR

[Panda, Dhabaleswar]

Thanks for your note. You are mixing-up two concepts: 1) CUDA-aware MPI and 2) GPUDirect RDMA. The 
CUDA-aware MPI concept allows MPI_Send and MPI_Recv to use data from GPU device directly. 
GPUDirect RDMA (GDR) allows data to be moved from a GPU to another GPU through through PCI 
interface using RDMA (say over InfiniBand) without going through the host memory. 

MVAPICH2 supports only CUDA-aware MPI.

MVAPICH2-GDR supports CUDA-aware MPI, GPUDirect RDMA (GDR), and many other advanced designs
related to GPU clusters to exploit performance and scalability. For example, you can get very low 
D-D latency (close to 2 microsec) with MVAPICH2-GDR. Thus, for GPU clusters with InfiniBand,  
we strongly recommend the users to use MVAPICH2-GDR. Please take a look at the MVAPICH2-GDR user 
guide from the following URL for all features and usage guidelines: 

http://mvapich.cse.ohio-state.edu/userguide/gdr/

Hope this helps. 

DK


 
________________________________________
From: mvapich-discuss-bounces at cse.ohio-state.edu on behalf of makai [makailove123 at 163.com]
Sent: Thursday, June 25, 2015 1:02 AM
To: mvapich-discuss at cse.ohio-state.edu
Subject: [mvapich-discuss] Difference between MVAPICH2 and MVAPICH2-GDR

I have installed MVAPICH2, and it says that it supports GPUDirect RDMA. MPI_Send and MPI_Recv could use addresses of device for data transmission.
So, what’s the difference between MVAPICH2 and MVAPICH2-GDR?

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