InfoWorld的回顾：英特尔的Westmere支柱的东西

ByPaul Venezia

快速AES加密，更好的可伸缩性和一致的每核性能使新的六核至强当之无愧的接班人的Nehalem

在今年以来英特尔发布了的Nehalem-EP四核Xeon CPU，围绕该芯片和它的新设计所需的所有喧哗已被证明准确。更大，更好，更快，更 - 一大堆比什么都重要，英特尔以前曾经发布。但是，当时，这是现在，当他们说，你有什么话对我最近做了什么？

今天，的Nehalem-EP让位给的Westmere-EP，或X5600系列至强CPU。而Nehalem处理器是一个大的性能提升比前一代的Westmere处理器是一个渐进的和可预测的改善，但它绝对是一个更好的芯片。Westmere的拿起其中的Nehalem不放过。

[ Also on InfoWorld: Intel's Westmere and AMD's Magny-Cours will change the face of IT forever. See "现代的多核心和下一代IT。" ]

关键Westmere-EP发展是两个cores (six total), the ability to address two DIMMs per channel at 1,333MHz, a 50 percent larger L3 cache, a set of instructions (AES-NI) for accelerating AES encryption, and better CPU power management. Westmere is the equal of Nehalem in single-threaded workloads, but far more scalable thanks to the additional two cores per die. The speed of Westmere's encryption operations will also turn heads.

事实上，与AES-NI指令所示的400％的性能提升，使整个磁盘加密几乎无法察觉。此前加密需要一个相当可观的性能折衷，但与Westmere处理器的AES性能跳，就成了一个没有脑子。而这只是中的AES-NI拥有许多潜在的应用案例之一。

Generation gapThe Westmere is built on the same basic guidelines as the Nehalem -- integrated memory controller, shared L3 cache per socket, and QPI (QuickPath Interconnect) -- but it's based on a 32nm process rather than Nehalem's 45nm. It runs up to 3.33GHz per core, and two threads per core with Hyper-Threading. That's 24 logical CPUs in a two-socket system, all balanced against 6.4GT/s QPI. It's definitely fast, but not terribly so when compared to Nehalem CPUs running at the same clock speed.

像Nehalem Westmere实现涡轮模式ramp up the clock speed on certain cores depending on load. Turbo Mode benefits single-threaded and lightly threaded applications by increasing the performance of a few cores when needed.

此外，Westmere的CPU的坐在同一插座为Nehalem的处理器。事实上，一些基于Nehalem的主板可以支持的Westmere已经，可能需要对BIOS进行更新。这是不是所有的Nehalem系统也是如此，但是，所以首先做一些研究。

In a bid to reduce power consumption, Westmere CPUs can essentially gate off unused cores and shut them down to reduce power, saving their state in cache. Yes, Nehalems can do this too, but Westmere chips can also gate off the uncore, or the region of the CPU that is tasked not with central processing but with memory control and L3 cache, bus controllers, and so on. Whereas a Nehalem could power gate each core, the Westmere can power gate everything, which has the benefit of reducing power draw at idle.

Also in the realm of reducing power consumption, the Westmere CPUs can use low-voltage DDR3 RAM running at 1.35 volts as well as standard DDR3 1.5-volt DIMMs. In addition to the relatively small reduction in power draw, low-voltage DIMMs generate less heat, thereby reducing overall cooling requirements, which is especially significant in servers and blades with high RAM counts.

Bench timeI had the opportunity to run a series of benchmarks on two sets of Westmere chips, the X5670s and X5680s. Both six-cores, the X5670s run 2.93GHz per core, while the X5680s run 3.33GHz per core. The tests were my standard array of real-world workloads rather than mainline benchmarking tools. They are composed of LAME MP3 audio conversion tests, gzip and bzip2 compression tests, MD5 calculation tests, and MP4-to-FLV video conversion tests. Each of these tests is a single-threaded process, but they are run concurrently at increasing levels to measure performance of the processors under various loads. I start at a 1:1 physical-core-to-process level, then ramp up the ratio significantly.

For these tests, I compared a two-CPU, 8-core 3.20GHz Nehalem W5580 system with 24GB of DDR3 RAM running at 1,333MHz to a two-CPU, 12-core 3.33GHz Westmere X5680 system with 24GB of DDR3 RAM running at 1,333MHz. Aside from the slight difference in clock speed, these are essentially the same chip, but one generation apart. All tests were run from RAM disks to eliminate disk I/O from interfering with the raw CPU tests, and Hyper-Threading was enabled.

结果是几乎你从Nehalem的CPU有两个核心的期望。在八个过程的最低并发级别，处理器证明基本相等，具有轻微的边缘到的Westmere X5680由于稍高的时钟速度。瘸腿的测试显示，Nehalem处理器运行27秒其中的Westmere敲了26秒。

The next iteration was 12 concurrent processes, and here the Westmere began to pull away, with an identical runtime of 26 seconds. The eight-core Nehalem was oversubscribed at this point and turned in a 37-second time. After that, the Westmere ran away with the test, culminating at a runtime of 149 seconds on the 96-process test, where the Nehalem fell in at 234 seconds. Basically, on a per-core basis, the Westmere isn't much faster than the Nehalem, but there are simply more cores and it scales far better because of that.

其它测试反映在略低于壮观方式同样的结果，不同之处在于具有的Westmere完成96过程运行比的Nehalem更快全102秒视频转换测试。

我跑的一组为2.93GHz的Westmere X5670s的相同测试套件，其结果表现出相同的缩放益处，但具有较慢时间由于减少的时钟速度相比于3.33GHz的X5680s。然而，即使在1：1的过程 - 芯比，X5670是大致持平与3.2GHz的Nehalem的W5580，可能是由于较大的L3高速缓存。

所有这一切都指向一个事实，即如果你的工作负载是单线程和单进程，然后Westmere处理器的CPU是不会给你买很多在他们年长。但是，如果您运行高度线程化的应用程序或在一次单线程应用多次迭代，Westmere处理器将提供显著的好处。当然，最大的多线程工作负载的一个是虚拟化，而这也正是Westmere处理器很可能会发现一个非常幸福的家庭。任何足够线程的虚拟化平台将大量使用在Westmere处理器的额外的核心，在同一插座上，并使用相同的RAM。

我也跑在新的AES-NI加密指令的特定测试。结果非常令人印象深刻。使用和不使用AES-NI补丁使用相同的OpenSSL的构建，AES加密测试案例表现出的性能提升了400％。测试很简单：加密与AES-256-CBC加密一个851MB的文件。如果没有使用AES-NI指令，一个的Westmere X5670 CPU始终完成13.5秒此任务。当使用了AES-NI的发动机，相同的任务只用了3秒。这是巨大的。

A Westmere for you在X5600系列是大的，有12个不同的Westmere-EP的CPU提供多种选择。该X5650，X5670，X5689和所有的CPU在夸95瓦特分别为2.26GHz，2.93GHz的，和3.33GHz的运行6芯充分补充。成本较低的E5620，E5630，和E5640s在80瓦特为2.26GHz，2.4GHz的，和2.53GHz的运行四个核分别。

的Westmere-EP也提供了在L5630和L5609 40瓦的选项，而在60瓦最低功耗的Nehalem-EP然。也有一些古怪，如95瓦的X5657，在运行主频为2.93GHz四个核，并且运行在3.46GHz的四个核130瓦的X5677。最后两个是为轻度线程工作量，可以利用更高的时钟速度，但并不需要额外的内核进行了优化。

If virtualization or highly threaded workloads are your game, the six-core models are definitely the way to go. If you're looking for raw clock speed on single-threaded workloads, the four-core models will give you better bang for your CPU buck. For the power miser, or those wanting to cram lots of lower-power CPUs into a rack, the 40-watt chips may be right up your alley. Essentially, there seems to be a Westmere chip to fit just about every scenario.

Related stories：

This story, "InfoWorld的回顾：英特尔的Westmere支柱的东西”最初发表于InfoWorld.com。Follow the latest developments inservers，处理器，and other硬件在InfoWorld.com。

Read more about hardwarein InfoWorld's Hardware Channel.

This story, "InfoWorld review: Intel's Westmere struts its stuff" was originally published byInfoWorld的。

Join the Network World communities onFacebookandLinkedInto comment on topics that are top of mind.

IT Salary Survey:结果是