# Hardwares

This section deals with hardwares utilized or considered on building HPC2.

## Servers

### DELL T7920

_Tower workstation_

We have one T7920 as our login/master node.

#### specs

Intel XEON Gold 5120 14 cores 28 threads \* 2

256G DDR4 memory

512G SSD

2T HDD\*2

Nvidia RTX 2080Ti

### DELL PowerEdge R740

_2U rack server_

We currently have **9** R740 as our computation nodes.

#### specs

Intel XEON Gold 5120 14 cores 28 threads \* 2

128G DDR4 memory for \[c1 - c3, c9], 256G DDR4 memory for \[c4-c7], 512G DDR4 memory for c8

512G SSD

#### extra specs

for c8, we have two extra 4T HDD (as hardware raid1)

for c9, we have two extra RTX2080Ti GPU cards and 6 extra 8T HDD (as hardware raid5)

#### misc

product no., the second digit is for the generation of Dell servers. 4 here is for 14 generation. As for the first digit, it seems that the larger number the more powerful computer it is.

* [spec sheet](https://i.dell.com/sites/csdocuments/Product_Docs/en/poweredge-r740-spec-sheet.pdf)
* [technical guide](https://www.dell.com/en-us/work/shop/povw/poweredge-r740)

**Notes**:

Quicksync is optional for this version of server. Seems no quicksync in our machines.

### Dell PowerEdge R640

_1U rack server_

We currently have **5** R640 server as our computation servers. (introduced on 2020.09.23)

c10-c14

#### specs

Intel XEON 6238R 2.2 GHZ 28 cores 56 threads 38.5M \*2

12\*32 G 2666 memory

SSD 480G

HDD 4T

## Others

### Rack

4 post 19 inch width standard(?) rack

### UPS

Uninterruptible power supply

control wire?

### Switch

* Huawei S1720-28GWR-4P

[Web configure guide](https://support.huawei.com/enterprise/zh/doc/EDOC1000169678)

192.168.1.253 is not a static ip. It could be assigned to other ips if there is a DHCP server on the upstream of it.

We currently has two of them, one is used for the main switch of the server room, and the other one is used within our cluster.

* Huawei S1700-16G-AC

### Ethernet cable

Cat6 2m or 5m

### Wireless AP

TP\_LINK: as an emegency Lan access.

## Hardware knowledges

### Jargons

* SFP: (small form factor pluggable transceiver), port may be seen on advanced switch or routers. Support 10Gb and Fibre.
* Backplane capacity(throughput):  [some interesting math on switch throughput](https://serverfault.com/questions/505125/calculating-backplane-capacity-of-a-switch), sometimes throughput may count in the unit of packets instead of traffic. In general backplane capacity should be larger than 2 times ports number times bandwidth of each ports on switch.
* POE: power supply by ethernet cable. see [here](https://kb.netgear.com/zh_CN/209/%E4%BB%80%E4%B9%88%E6%98%AF-PoE-%E4%BB%A5%E5%A4%AA%E7%BD%91%E4%BE%9B%E7%94%B5). PSE: power provider, PD: power consumer.
* KVM switch: one IO set control multiple nodes
* SAS vs. SATA: [see the comparison](https://www.diffen.com/difference/SATA_vs_Serial_Attached_SCSI)
* Link aggregation: one logical channel with more than one physical channel of ethernet
* Port security and isolation: [term in switch configuration](https://cshihong.github.io/2017/11/16/%E7%AB%AF%E5%8F%A3%E5%AE%89%E5%85%A8%E5%92%8C%E7%AB%AF%E5%8F%A3%E9%9A%94%E7%A6%BB/)

## General References

* [Basics on network: practical perspective](https://www.dell.com/community/%E6%95%B0%E6%8D%AE%E5%AD%98%E5%82%A8%E8%AE%A8%E8%AE%BA%E5%8C%BA/%E7%BD%91%E7%BB%9C%E5%9F%BA%E6%9C%AC%E5%8A%9F%E7%B3%BB%E5%88%97-%E7%BB%86%E8%AF%B4%E7%BD%91%E7%BB%9C%E9%82%A3%E4%BA%9B%E4%BA%8B%E5%84%BF-3%E6%9C%8826%E6%97%A5%E6%9B%B4%E6%96%B0/td-p/7045185)
