【文章标题】：SiFive’s First Server Platform 【文章标题】：SiFive 的首个服务器平台
【文章正文】： Hello you fine Internet folks, 你好，各位互联网朋友们，
The RISC-V ecosystem is an ever-evolving one especially in the high-performance application class silicon space. We have seen a number of acquisitions and exits in the past year with Ventana being acquired by Qualcomm in December of last year and the wrapping up of operations of Condor Computing. We have also seen silicon being taped out with the most prolific chip being SpacemiT’s K3 SoC with Tenstorrent following suit with their Atlantis SoC along with Akeana taping out their test chip. RISC-V 生态系统一直在不断发展，尤其是在高性能应用级芯片领域。过去一年里，我们见证了一系列收购和退出：Ventana 于去年 12 月被高通收购，Condor Computing 也停止了运营。我们还看到一些芯片完成流片，其中最多产的是 SpacemiT 的 K3 SoC，Tenstorrent 紧随其后推出了 Atlantis SoC，Akeana 也流片了他们的测试芯片。
But today we are not talking about those companies nor those chips. Today we are talking about a company that has been in the RISC-V scene since the very beginning, SiFive and their new platform, the SiFive BigSky SF-2U870. 但今天我们不讨论那些公司，也不讨论那些芯片。今天我们要讨论的是一家从一开始就活跃在 RISC-V 领域的公司——SiFive，以及他们的新平台 SiFive BigSky SF-2U870。
Aiming for the Sky 瞄准天空
The BigSky SF-2U870 (BigSky) platform consists of: BigSky SF-2U870（BigSky）平台包括：
- A standard 19” 2U server
- 标准 19 英寸 2U 服务器
- 32 P870-D cores running at 2.2 GHz1
- 32 个 P870-D 核心，运行频率 2.2 GHz1
- 256 GB of DDR5-5600
- 256 GB DDR5-5600 内存
- 64 Lanes of PCIe 5.0 plus 4 Lanes of PCIe Gen 3.0
- 64 条 PCIe 5.0 通道加 4 条 PCIe Gen 3.0 通道
- Support for double-wide GPUs (Up to 450W)
- 支持双宽 GPU（最高 450W）
- 10/25 GbE OCP 3.0 NIC
- 10/25 GbE OCP 3.0 网卡
- 960 GB SATA SSD for the OS
- 用于操作系统的 960 GB SATA SSD
- 3.84 TB U.2 NVMe SSD for data storage2
- 用于数据存储的 3.84 TB U.2 NVMe SSD2
To be frank, this platform is boring, and that is a good thing. Boring platforms are the ideal state for a platform because it means that you can just start developing for the platform instead of messing around trying to get the system up and running. 坦率地说，这个平台很乏味，而这是一件好事。乏味的平台是平台的理想状态，因为这意味着你可以直接开始为平台进行开发，而不必折腾着让系统启动并运行。
Comparing the BigSky SF-2U870 to SiFive’s prior development board, the SiFive HiFive Premier P550, and we can see that the BigSky is a much more capable platform. 将 BigSky SF-2U870 与 SiFive 之前的开发板 SiFive HiFive Premier P550 进行比较，我们可以看出 BigSky 是一个能力强大得多的平台。
The biggest change here is not the number of cores, the increase of memory bandwidth, or even the over 64x-ing of the PCIe bandwidth. It is the support for the RVA23 standard which means that not only does it have RVV support but it also means that it can run Ubuntu 26.04 straight out of the box which requires RVA23 support. 这里最大的变化不是核心数量、内存带宽的增加，甚至也不是 PCIe 带宽提升超过 64 倍。而是对 RVA23 标准的支持，这意味着它不仅支持 RVV，还意味着它可以开箱即用地运行 Ubuntu 26.04，而后者需要 RVA23 支持。
Now, let’s compare the BigSky’s SoC to the other SoCs that are currently on the market to see how it compares to other devices on the market. 现在，让我们将 BigSky 的 SoC 与市场上当前的其他 SoC 进行比较，看看它与市场上其他设备相比如何。
The most comparable SoC is Intel’s Xeon 6532P-B with the same number of cores, the same base clock, and the same memory subsystem. However, this is where they start to differentiate themselves with BigSky having the advantage of more PCIe lanes and likely lower power while the Xeon 6532P-B has the advantages of SMT2 support, a 3.9 GHz boost clock, and a wider CPU core. Looking at the AMD EPYC 8325P and we see that the BigSky platform has few, if any, specification advantages over the EPYC 8325P except for possibly lower power draw. 最具可比性的 SoC 是英特尔的 Xeon 6532P-B，它拥有相同的核心数量、相同的基础频率和相同的内存子系统。然而，它们开始出现差异：BigSky 的优势在于拥有更多 PCIe 通道且功耗可能更低，而 Xeon 6532P-B 的优势在于支持 SMT2、拥有 3.9 GHz 睿频以及更宽的 CPU 核心。再看 AMD EPYC 8325P，我们发现 BigSky 平台相对于 EPYC 8325P 几乎没有规格优势，除了可能更低的功耗。
The most interesting comparison here is against the Ampere Altra Q32-17 because the Altra platform was used in the same development system role that the BigSky system is being marketed for. The BigSky system has the advantage of higher clock speeds, a wider core, and PCIe Gen 5 support with the Ampere Altra’s advantages being the number of lanes, more memory bandwidth, and a lower TDP. 这里最有趣的对比是与 Ampere Altra Q32-17 的对比，因为 Altra 平台曾被用于与 BigSky 系统所面向的相同的开发系统角色。BigSky 系统的优势在于更高的时钟频率、更宽的核心以及 PCIe Gen 5 支持，而 Ampere Altra 的优势在于通道数量、更高的内存带宽和更低的 TDP。
However, the elephant in the room is that the Ampere Altra Q32-17 is the lowest end SKU for the Ampere Altra lineup with the lineup going all the way up to the Q80-33 which is a 80 cores at 3.3 GHz with a 250 W TDP. In an “Apples-to-Apples” comparison, the Q80-33 would beat out the BigSky system in terms of performance. 然而，显而易见的问题是，Ampere Altra Q32-17 是 Ampere Altra 产品线中最低端的 SKU，而该产品线一直延伸到 Q80-33，后者拥有 80 个核心、3.3 GHz 频率和 250 W TDP。在“苹果对苹果”的对比中，Q80-33 在性能方面会击败 BigSky 系统。
Final Words 结语
The BigSky is boring, and as I said up top, that is a good thing. There is a lot of work that into shipping a development platform that just works; one where software developers spend their time writing code instead of chasing firmware that hasn’t caught up to the silicon yet. BigSky 很乏味，正如我上面所说，这是一件好事。要推出一个开箱即用的开发平台需要大量工作；一个让软件开发人员把时间花在编写代码上，而不是追赶尚未跟上芯片的固件的平台。
SiFive isn’t trying to beat x86 or Arm with the BigSky platform and it doesn’t have to. This is a development system, and for that job it is fit for purpose not because of the memory bandwidth or the PCIe lanes but because it supports RVA23. The one of the largest weaknesses for the RISC-V ecosystem has been the lack of RVA23 silicon and boring platforms that can just run things like CI with no fuss. That is the gap that SiFive is filling with BigSky which hopefully should be available for developers to get their hands on soon. SiFive 并不试图用 BigSky 平台击败 x86 或 Arm，而且也没必要这样做。这是一个开发系统，就这一用途而言，它之所以胜任，不是因为内存带宽或 PCIe 通道，而是因为它支持 RVA23。RISC-V 生态系统最大的弱点之一一直是缺乏 RVA23 芯片以及能够毫无麻烦地运行 CI 等任务的乏味平台。这正是 SiFive 用 BigSky 填补的空白，希望开发人员很快就能拿到它。
At the time of publishing this article, SiFive’s claimed clockspeeds for the BigSky SF-2U870 (BigSky) platform are inconsistent, even on the same product page. In one section it’ll claim a 2.0Ghz operating frequency while in another it’ll claim 2.2ghz. So for simplicity and our sanity, we are going to just going to assume a 2.2Ghz operating speed for BigSky. 在本文发布时，SiFive 对 BigSky SF-2U870（BigSky）平台所宣称的时钟频率并不一致，即使在同一产品页面上也是如此。一个部分声称运行频率为 2.0GHz，而另一部分则声称 2.2GHz。因此，为了简单起见，也为了我们的理智，我们暂且假定 BigSky 的运行速度为 2.2GHz。
The product page lists “2x 7.68TB U.2 NVMe SSD” while elsewhere it lists the data storage as “3.84TB Data SSD”. Given the current pricing environment for NAND, either storage config is plausible. However if anyone from SiFive is reading this, please fix. 产品页面列出“2x 7.68TB U.2 NVMe SSD”，而其他地方则将数据存储列为“3.84TB Data SSD”。鉴于当前 NAND 的定价环境，两种存储配置都有可能。不过，如果有 SiFive 的人读到这篇文章，请修正。