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Difference between ITO and Genkai

Hardware

Between ITO and Genkai, the number and specifications of computation nodes are significantly different.
Please select the appropriate amount of resources according to the parallelism of the program to be executed and the amount of memory used.

The main differences between ITO and Genkai backend nodes are as follows:

ITO Subsystem A vs Genkai Node Group A

Item

ITO A

Genkai A

Ratio

Number of Nodes

2000

1024

0.51

Cores per Node

36

120

3.3

Speed per Node
(SPEC CPU2017 FP Rate)

200

1040

5.2

Memory per Node

192GB

512GB

2.7

ITO Subsystem B vs Genkai Node Group B

Item

ITO B

Genkai B

Ratio

Number of Nodes

128

38

0.29

GPU Speed per Node (FP64)

21.2TF

134TF

6.3

Memory per Node

384GB

1TB

2.7

Thus, the performance and memory per node of Genkai’s backend nodes are approximately 2.7 to 6.3 times higher than ITO’s,
but the total number of nodes is significantly smaller.
Therefore, using the same number of nodes as ITO may result in wasted computing resources and longer latency before execution starts.

Application for Use and Changing Contracts

While ITO required printing and mailing an application form for use or contract changes,
Genkai allows applications and modifications to be made directly through a web browser.
For details, please refer to the following page:

Usage Fee

While ITO charged a fixed monthly fee for all usage,
Genkai adopts a pay-as-you-go system for shared use of compute nodes.
However, fixed usage and storage fees are still charged monthly in Genkai.

In addition, Genkai charges a basic monthly fee of 130 yen per application for use.
This basic fee includes the right to use 1TB of large-scale storage.

For more information on usage fees, please refer to the following:

Login Node

Specify the following as the IP address of the login node for Genkai: genkai.hpc.kyushu-u.ac.jp

On the login node, the maximum memory usage per process is limited to 24GB.

User and Group

All user accounts on Genkai are newly created.
Therefore, user accounts used in ITO cannot be used on Genkai.

On Genkai, each user account can belong to only one group.
In ITO, a single user account could belong to multiple groups (for multiple projects)
and switch groups using the newgrp command.
However, this made it difficult to manage files for each project because files from completed and ongoing projects were mixed in the same home directory.

To improve this, Genkai issues a separate user account for each project.
When the same person participates in multiple projects,
the setfacl command can be used to share files or directories between user accounts.
This allows flexible access control for any file or directory you own.

For details on sharing files among users, see the following:

Storage

In addition to the large storage where the home directory is located,
Genkai provides Fast Storage consisting of SSDs.
For more details on using storage, refer to the following:

Newly Available Software

Genkai newly provides the following software:

Software with Usage Restrictions

Some of the software provided in ITO will have restrictions on Genkai, as shown below.

  • SAS
    Available only under a bring-your-own-license format.
    If you wish to use it, please contact the following:
    Contact

  • ANSYS
    Due to license restrictions, it is no longer provided on the national joint-use system.

  • MSC Products
    Software such as Marc/Mentat/Nastran/Patran can only be used on Genkai’s computation and login nodes.
    Using MSC products installed on external PCs, which was possible on ITO, is not available on Genkai.
    Remote GUI startup is also unavailable.

module Command

On ITO, the following command displayed all available modules, regardless of dependencies:

On Genkai, only modules that can be loaded at that time are displayed.
For example, a module dependent on intel will appear in the result of the module avail command after loading the intel module.

Programs Compiled on ITO

To achieve maximum performance on Genkai,
programs compiled on ITO should be recompiled using Genkai’s compilers.
Although Genkai’s CPU and GPU architectures are compatible with ITO,
depending on the libraries used and other factors, recompilation may be necessary to run properly.

Job Scripts of ITO

Genkai uses the same Fujitsu Technical Computing Suite job scheduler as ITO,
so there are no major changes in how job scripts are written.

However, the following items need to be modified:

  • Specification of the resource unit using -L rscunit, which was required on ITO, is not necessary on Genkai.
  • The resource group specified by -L rscgrp differs between ITO and Genkai.
  • Module names loaded within job scripts often differ between ITO and Genkai.

Interactive Use

On Genkai, interactive jobs can be reserved and used instead of ITO’s basic and large front-end nodes.

Interactive use via a web browser is also possible using Open OnDemand.