Benchmarking the HP Z840 Workstation for Video, Part 2: Encoding

This is the second segment of my review of the HP Z840; in the 第一段，我比较了编辑和渲染时的性能. 这次，我分析了编码过程中的性能.

和以前一样，我试图回答多个问题:

•第一, how much faster is the Z840 compared to my older Z800 workstation in multiple encoding chores?
•第二，启用或禁用http时性能更快吗?
• Third, did the disk speed on the respective test systems significantly impact encoding performance. More specifically, does using SSD disks improve encoding performance over older HDD drives?

这次测试有一个小问题:Telestream Vantage, 像所有企业级编码器一样, 在干净的系统上运行效果最好, 不会安装在Z800上, upon which I’ve installed nearly every encoding and video analysis program known to man. 这并不奇怪. 所以我无法在那个系统上测试Vantage.

然而, Vantage在我家里的一台双cpu HP Z600上运行得很好, though it’s not nearly as powerful as the Z840 or Z800 in clock speed or number of CPU cores. 和Z800一样，它也配备了传统的硬盘驱动器.

表1(下) 总结了每个系统的关键组成部分. 还有很多影响性能的细节, 包括总线和内存速度, 但这些是关键的区别.

表1. 测试系统的主要组成部分.

测试描述

让我们从我运行的测试的简要描述开始.

• Adobe媒体编码器(AME): Rendering time to output a 96-second 4K test file to five Apple iDevice presets. AME was installed on the boot drive and all files were saved to the C drive, 源文件来自Z840上各自的驱动器.
• 压缩: Rendering time to output a 5:13 (min:sec) 1080p AVCHD file to Squeeze’s multiple-bitrate preset, which converts the source file into four streams and formats them for delivery via HTTP Dynamic Streaming (HDS), 苹果的HTTP直播(HLS), 微软平滑流(MSS), MPEG-DASH, 和MP4文件, 将单个输入文件转换为20个输出. Squeeze was installed on the boot drive and all files were saved to the C drive, 源文件来自Z840上各自的驱动器.
• x265: Rendering time to simultaneously encode three 5-second 1080p source files to HEVC format. 对于这个测试, I created three folders on each source disk and ran x265 via command line with files saved to the source disk.
• VP9: Rendering time to simultaneously encode three 5-second 1080p source files to VP9 format. 对于这个测试, I created three folders on the test disk and ran VP9 via command line with files saved to the source disk.
• 优势: Rendering time to output the 96-second 4K source file to six output streams at various configurations. Vantage was installed on the boot drive and all files were saved to the C drive, 源文件来自Z840上各自的驱动器.

As before, I tested with HTT enabled and disabled, and rendered from all drives on the Z840. 表2(下) 显示每台计算机的总体最快时间, 右侧为Z840交付的百分比下降, 当差值超过35%时显示为绿色. Note that I used completely different encoding parameters for Squeeze, AME, 和优势, 以及不同的挤压源文件, 所以编码时间是不可比较的.

表2. Z840到Z800 (Vantage的Z840到Z600). 所有时间以秒为单位.

Vantage的改善最大, 考虑到它的结果来自速度较慢的Z600，这并不奇怪, 但还是令人印象深刻. The only encoder that didn’t cross the 35% threshold was WebM encoding from the command line; a brief look at 图1(下面) 解释了为什么. 具体地说, 图1 is a frame grab from Windows Performance Monitor showing 编码WebM和HEVC三个流时的CPU利用率 on the Z840. 如你所见, 即使在制作三个WebM流时也是如此, 利用率远低于20%, 而HEVC为60%-90%.

图1. 编码WebM和HEVC三个流时的CPU利用率.

Just for fun, I ran a quick test encoding seven WebM streams from the Turbo SSD G2 drive. 整体 encoding time increased by only 4 seconds, with CPU utilization hovering around 19%. Given the lack of CPU headroom when encoding only three streams of HEVC, it’s doubtful that I could have encoded even a single additional stream without noticeably slowing performance. 虽然x265的时间更快 表2, you should be able to produce many more simultaneous WebM streams on a single computer than HEVC, 使WebM成为更快的编码器.

整体, 对于大多数项目, a new Z840 should be able to deliver significant performance boosts over existing stations.