刚申到了天河二号的试用，大家有什么想测试的？

[RqPS6rhmP3Nyn3Tm]

[flaminigo]

@boter 不能这样说的。 bit coin mining 就是在不断的计算 hash key 。这种单一的计算很容易用硬件实现。需要的计算资源也很少，比如内存和 I/O ，只是 CPU demanding 的。所以会出现很多 FPGA 的矿机。

而我们一般的计算是 general computing 。有很多不同的计算模型，需要的资源也不一样。比如 渲染 和 解方程 的计算模型就不一样。渲染需要很高的 I/O throughput ，计算却相对简单。所以用 CUDA pipeline 实现很方便。而解方程需要很多 memory 来存储 sparse matrix 。对 memory 的访问又相当随机，因为和 pivot condition 有关系。 pivot condition 决定了数值的稳定性。所以是 computing 和 memory 都很 demanding 的。

像渲染和解方程，就很难放到 FPGA 矿机上做。即使可以，运算的速度和规模也远远赶不上通用的计算机。

[flaminigo]

@fzinfz super computer 不是这样用的。中文输入好累，请允许我打英文。
Nodes of a supercomputer, such as Tianhe II, are divided into two types: interactive nodes and computing nodes.

Interactive nodes are for the interaction with users.We use those nodes for editing files, compiling programs and submitting jobs. We may run the program on those nodes by './program'. But the computing is conducted on interactive nodes of which the performance are usually bad.

To drain the performance of a supercomputer, we should submit our program to one or more computing nodes. We usually write a job description file specifying the program we want to run, resources we need during computing and the expected running time/duration of our program. We submit our job to computing nodes via the job management system that reads info from the job description file. In this way, the computing is conducted on the powerful, resourceful and high speed computing nodes.

Different supercomputers have different job management systems. I have ever used systems of IBM and Cray.

[flaminigo]

@hedaors 说的对！

[fzinfz]

@flaminigo Thanks for your detailed explanation, which've taught me more about super computer~

to all ：
搜到 2 份很好的天河 2 文档，有兴趣的 V 友可以看看 ：
官方： https://www.openstack.org/assets/presentation-media/How-to-Deploy-OpenStack-on-Tianhe-2-Supercomputer-2.pdf
非官方： http://www.netlib.org/utk/people/JackDongarra/PAPERS/tianhe-2-dongarra-report.pdf

另外附上 openstack 的官方架构介绍，好复杂。。。
http://docs.openstack.org/juno/install-guide/install/apt/content/ch_overview.html

[flaminigo]

@fzinfz 似乎是这个文档才是 manual 。 http://www.nscc-gz.cn/userfiles/files/nsccth2sc.pdf