With the gradual deepening of the national policy on the Development of the West Regions, many large and medium-sized data centers have landed in high-altitude areas. In this context, the impact of high altitude on data centers, especially on the electronic devices of data centers, has become the focus of user concern. In addition to its impact on the heat dissipation and insulation performance of electronic devices, high altitude will also cause breakdown of electronic devices, such as bit flipping and downtime, because of the large neutron flux.
Atmospheric neutrons are produced by the nuclear reaction between primary cosmic rays and atomic nuclei such as oxygen and nitrogen in the earth's atmosphere. The neutron flux increases exponentially with the increase of altitude. The single event effect (SEE) of atmospheric neutrons, especially medium- to high-energy neutrons, has become an un-ignorable threat to the reliability of large computing systems on the ground, such as high-performance computers.
As an important infrastructure for data storage, processing and management, data centers will cause immeasurable loss in case of data error or loss due to neutron causes. In order to better meet the basic requirements of high-altitude data centers for storage components to resist the influence of neutrons, Union Memory carries out neutron tests in collaboration with well-known laboratories in China to satisfy the needs of data centers for SSDs with high reliability.
1. Basic Information on Testing Environment
Configurations for this test are as follows:
(1) Server Configuration:
CPU: Intel 5218 *2
Memory: 8*32G
Network Interface Card: 2*10GE+2*GE
(2) Number of SSDs Tested
The products tested are mainly enterprise-grade UH8 series products developed by Union Memory, and the number of SSDs tested is 12, covering UH810a, UH830a, UH811a, UH831a and other ESSDs.
(3) Neutron Fluence Rate
The neutron fluence rate for the test is 2.67*105n/(cm2·s).
Under the domestic ground conditions, Ngari Prefecture is one of the regions with the highest neutron quantity, and the neutron fluence rate is about 509n/ (cm2•h) (En≥1MeV) . Under the condition of constant neutron irradiation, the accumulated neutron fluence received by SSDs under this test condition is far more than the max. cumulative neutron fluence that can be received by the ground in other regions in China (see Fig.2 for comparison example).
Fig. 1: Neutron Generator under Test Scenario – Target Station Fig. 2: Schematic Comparison of Cumulative Neutron Fluence
2. Test Process and Results
Fig. 3: Overall Diagram of Testing Environment Fig. 4: Monitoring Diagram of Testing Site
(1) Test Process
All disks are irradiated at the same neutron fluence rate, starting when the neutron irradiating fluence rate meets the test requirements and ending when the disk function fails. The run time is recorded through the automated test script;
5 SSDs are divided into one group, and a total of 3 groups are completed in this test;
The test operators monitor the SSDs running status in real time in the monitoring room and make the statistics.
(2) Test Results
① Measurements of Partial Single Disks
Fig. 5: Measurements of UH810a/UH830a Single Disk - 1 Fig. 6: Measurements of UH811a/UH831a Single Disk - 1
Fig. 7: Measurements of UH810a/UH830a Single Disk -2 Fig. 8: Measurements of UH811a/UH831a Single Disk -2
② Statistics of Run Time in Detail
|
Sr. No. |
SSD Model |
Run Time/min |
Mean Run Time/min |
Total Mean Time/min |
|
1 |
UH810a/UH830a |
28 |
6.5 |
11.7 |
|
2 |
10 |
|||
|
3 |
3 |
|||
|
4 |
2 |
|||
|
5 |
UH811a/ UH831a |
99 |
12.3 |
|
|
6 |
16 |
|||
|
7 |
14 |
|||
|
8 |
3 |
|||
|
9 |
5 |
|||
|
10 |
0 |
|||
|
11 |
4 |
|||
|
12 |
32 |
|||
|
Note 1: Mean Time=Sum of Effective Run Time of SSDs/Number of Effectively Tested Disks (Excluding Max. and Min. Run Times) Note 2: Run Time in the statistics is the duration of normal read/write of SSDs irradiated by neutrons. |
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The test results show that under irradiation at the same neutron fluence rate, the minimum mean run time of UH8 series products is 6.5min, and the total mean run time is 11.7min.
3. Analysis of Test Data
The service life of Union Memory SSDs is generally 5 years. Under the base condition of neutron fluence rate in Ngari Prefecture, the cumulative neutron fluence of Union Memory SSDs in 5 years is 2.23E+07 n/ cm2 . Under laboratory conditions, in order to achieve a 5-year service life, Union Memory SSDs need to run for 83s at a neutron fluence rate of 2.67*105 n/(cm2·s).
In this test, the mean run time of Union Memory UH8 SSDs is 11.7min , verifying that Union Memory UH8 SSDs can operate normally under the natural environmental condition of high neutron flux and has 5 years of service life, and has high reliability to resist certain neutron irradiation.
It can be seen from the above measurements that Union Memory enterprise-grade UH8 SSD products have a certain neutron resistance, with built-in ECC, RAID data recovery, reread and other functions, which can timely correct the bit upset and other problems caused by neutrons, ensure normal operation during the service life of SSDs, and provide highly reliable SSD products for high-altitude data centers, helping build stronger and more secure data centers in the western regions.
Address: 19th Floor, Block B, Ramaxel Houhai Center, Nanshan District, Shenzhen
Tel: +86 755-2681 3300
E-mail: support@unionmem.com
