New allocations for Bridges GPU nodes

Starting on June 26 2017, there will be a new type of allocation for Bridges:  Bridges GPU.  Only users with a Bridges GPU allocation will be able to run on the Bridges GPU nodes. Users with a Bridges Regular Memory allocation will be able to run on the Regular Memory nodes only.

What is changing?

On June 26 2017, users with Bridges Regular Memory (RM) allocations will no longer be able to use the GPU nodes on Bridges; a separate Bridges GPU allocation will be needed to use the Bridges' GPUs. If you have an existing Bridges RM allocation and want to continue to use GPUs, you should transfer some of your Regular SUs to a Bridges GPU allocation.

To determine how many RM SUs you should convert to GPU SUs, you need to know how Bridges GPU SUs compare to Bridges RM SUs and the charging calculation for both types of GPUs.

Charges for GPU nodes

Each GPU SU corresponds to 14 Regular SUs.

Bridges contains two kinds of GPU nodes: NVIDIA Tesla K80s and NVIDIA Tesla P100s. Because of the difference in the performance of the nodes, the charges are different for the two types of nodes.

 K80 nodes 

The K80 nodes hold 4 GPU units each, each of which can be allocated separately.  Service units (SUs) are defined in terms of GPU-hours:

1 GPU-hour = 1 SU

Note that the use of an entire K80 GPU node for one hour would be charged 4 SUs.

P100 nodes

The P100 nodes hold 2 GPU units each, which can be allocated separately.  Service units (SUs) are defined in terms of GPU-hours:

1 GPU-hour = 2.5 SUs

Note that the use of an entire P100 node for one hour would be charged 5 SUs.

 

What is staying the same?

The way to submit and run jobs on Bridges' GPU nodes will be exactly the same after this change. You will not need to change anything in your job scripts or your way of working.

 

I want to keep using GPUs. What should I do?

You should transfer some or all of your existing Bridges RM allocation to a Bridges GPU allocation.  You can also transfer an allocation on another XSEDE resource to a Bridges GPU allocation. To calculate how many RM SUs to convert to GPU SUs, keep in mind:

  • Each GPU SU corresponds to 14 RM SUs.
  • The charges are different for the K80 and the P100 nodes.
    • K80 nodes are charged at 1 SU per GPU-hour.  The use of an entire K80 node for an hour is charged 4 SUs.
    • P100 nodes are charges at 2.5 SU per GPU-hour.  The use of an entire P100 node for an hour is charged 5 SUs.

You can transfer Bridges RM SUs to Bridges GPU SUs through the XSEDE User Portal(XUP).  Note that it usually takes around 3 business days for transfers to be processed.  To initiate a transfer, go to https://portal.xsede.org/submit-request and log in. Click the blue Actions button and choose 'Transfer'. 

 

If you have any questions about your allocation or how to transfer your SUs please do not hesitate to contact us at grants@psc.edu.