# TITAN -- It's a tricky beast, but it was [1st](https://www.top500.org/lists/2012/11/) (on the [top 500](https://www.top500.org/lists/2017/11/))!
And it is still 5th.
## AMD Interlagos based machine, like OIC phase 5.
## Differences from the standard Intel Linux Cluster
### AMD Interlagos based machine, like OIC phase 5.
The key is there are only one floating point unit per two cores. So from a science perspective there are only 8 cores per node, not the sixteen listed. Additionally your code needs to bind to just one core per pair. See [Cray XK7 CPU info](https://www.olcf.ornl.gov/support/system-user-guides/titan-user-guide/#333)
## Service nodes run mpimom processes and PBS scripts -- (this complicates what PBS scripts can do)
## There is only one GPU per node, i.e. 16 CPU, 8 FPU, 1 GPU. It's generally on you to manage this.
### Service nodes run mpimom processes and PBS scripts
this complicates what PBS scripts can do. You can only run 50 aprun's that is 50 independent mpi applications in one job script.
### There is only one GPU per node, so 16 CPU, 8 FPU, 1 GPU.
It's generally on you to manage this.
# Qsub chaining jobs
qsub -W depend=afterok:$JOBID fourth_1.sh
```shell-session
qsub -W depend=afterok:JOBID fourth_1.sh
```
* _afterok_ if you need previous job to be successful
* _afterany_ if you don't care
If you are having trouble, and there is not an example in the repo, it's probably best to just contact slack/here @epd [email](mailto:doakpw@ornl.gov)
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If you are having trouble, and there is not an example in the repo, it's probably best to just contact slack/here @epd or [email](mailto:doakpw@ornl.gov)
