Draft:Time Card (Hardware)
| Submission rejected on 14 November 2023 by S0091 (talk). This topic is not sufficiently notable for inclusion in Wikipedia. Rejected by S0091 6 months ago. Last edited by Citation bot 43 days ago. |  |
| Submission declined on 14 November 2023 by S0091 (talk). This submission is not adequately supported by reliable sources. Reliable sources are required so that information can be verified. If you need help with referencing, please see Referencing for beginners and Citing sources. This draft's references do not show that the subject qualifies for a Wikipedia article. In summary, the draft needs multiple published sources that are: Declined by S0091 6 months ago.
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| Submission declined on 13 November 2023 by Vanderwaalforces (talk). This draft's references do not show that the subject qualifies for a Wikipedia article. In summary, the draft needs multiple published sources that are: Declined by Vanderwaalforces 6 months ago.
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| Submission declined on 6 November 2023 by Zxcvbnm (talk). This draft's references do not show that the subject qualifies for a Wikipedia article. In summary, the draft needs multiple published sources that are: Declined by Zxcvbnm 6 months ago.
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Comment: See also Draft:Open Time Card. S0091 (talk) 16:50, 17 November 2023 (UTC)
- Comment: Meta is not an independent source for their own software. S0091 (talk) 19:54, 14 November 2023 (UTC)
- Comment: Most of the sources are not reliable (github, git.kernal, social media, blogs, etc.) and most of the content is unsourced. S0091 (talk) 14:14, 14 November 2023 (UTC)
- Comment: A bunch of Youtubers do not count as reliable sources with regards to this topic. It requires actual coverage in the media at large that would merit a standalone page. ᴢxᴄᴠʙɴᴍ (ᴛ) 07:08, 6 November 2023 (UTC)
 | A major contributor to this article appears to have a close connection with its subject. (November 2023) |
 An early revision of the Time card | |
| Date invented | 2020 |
|---|---|
| Invented by | Meta team led by Ahmad Byagowi and Oleg Obleukhov |
| Connects to | Motherboard via:
GNSS antenna via: Peripheral via: |
| Common manufacturers | Safran Oscilloquartz |
Time Card is a hardware (extension) developed by Meta in partnership with the Open Compute Project to provide the operating system with accurate and precise times. The code is open source and available on GitHub.
Etymology[edit]
Initially the card was called Timing card due to its functionality to provide timing for the host system. However, later on it got a name change to become the Time Card.[1]
History[edit]
Early development for the Time Card by Meta and Open Compute Project was in a special workstream called Time Appliance Project.[2] As development progressed more details about the implementation were published in the "Time Card and Open Time Server" Institute of Electrical and Electronics Engineers (IEEE).[3][4][5][6]
There is an ongoing IEEE Project Authorization Request being lead by Meta working on standardizing the design of the Time Card to maximize interoperability across various Time Card implementations.[7]
Design[edit]
Original Time Card contained a global navigation satellite system (GNSS) receiver, atomic clock and a phase-locked loop (PLL) implemented on field-programmable gate array (FPGA). In design atomic clock acted as a backup source in case of GNSS signal loss by providing 10MHz output to the PLL.However, without periodic calibration of the atomic clock this design proved to provide a poor holdover performance.
In 2021 design was updated to include atomic clock with a pulse-per-second signal input which ensured constant calibration of the oscillator and better holdover characteristics.[8]
Depending on the choice of oscillator the holdover performance may differ. The best measured holdover performance of the Time Card with a miniature rubidium atomic clock was one microsecond over the period of three days.[8]
The code is open source and available on GitHub.[9] There are various derivatives of the Time Card that are also open sourced such as the ART Card by Safran[10] or OSA5400 Card by Oscilloquartz.[11]
Reception[edit]
After initial publication at Meta's engineering blog, the announcement of Time Card was covered in several online newspapers such as TechCrunch,[12] ZDNET[6] CNET[5] and EE Times.[9]
References[edit]
- ^ "Time Card Spec revision revision 1.0". opencompute.org. Opencompute.
- ^ "Time Appliances Project (TAP)". opencompute.org. Opencompute.
- ^ Byagowi, Ahmad; Obleukhov, Oleg (2022). "Time Card and Open Time Server". 2022 IEEE International Symposium on Precision Clock Synchronization for Measurement, Control, and Communication (ISPCS). IEEE. pp. 1–6. doi:10.1109/ISPCS55791.2022.9918379. ISBN 978-1-6654-7032-2.
{{cite book}}:|journal=ignored (help) - ^ Obleukhov, Oleg; Byagowi, Ahmad. "The future of Coordinated Universal Time" (PDF). ITU.
- ^ a b "Facebook shares its Time Card atomic clock tech to speed internet services". CNET.
- ^ a b "Does anyone really know what time it is? Facebook does". ZDNET.
- ^ "Standard for Architecture and Interfaces for Time Card". IEEE SA. IEEE.
- ^ a b Byagowi, Ahmad; Obleukhov, Oleg (11 August 2021). "Open-sourcing a more precise time appliance". Engineering at Meta. Meta.
- ^ a b "Facebook Open Sources Time Appliance For Data Center Networks". EE Times. 12 August 2021.
- ^ "ART Source Code". Safran. 25 April 2022.
- ^ "OSA5400". Oscilloquartz.
- ^ "Facebook engineers develop new open source time keeping appliance". TechCrunch. 11 August 2021.
