Software Archives
GCC vs. Clang Compiler Performance On NVIDIA Xavier's Carmel ARMv8 Cores

Since receiving the powerful NVIDIA Jetson AGX Xavier with its ARMv8 Carmel cores on this Tegra194 SoC a while back, it's been quite a fun developer board for benchmarking and various Linux tests. One of the areas I was curious about was whether GCC or Clang would generate faster code for this high performance ARM SoC, so here are some benchmarks.

13 January 2019 - 6 Comments
The Many New Features & Improvements Of The Linux 5.0 Kernel

Linus Torvalds just released Linux 5.0-rc1, what was formerly known as Linux 4.21 over the past two weeks. While the bumping was rather arbitrary as opposed to a major change necessitating the big version bump, this next version of the Linux kernel does come with some exciting changes and new features (of course, our Twitter followers already have known Linux was thinking of the 5.0 re-brand from 4.21). Here is our original feature overview of the new material to find in this kernel.

6 January 2019 - 4 Comments
Linux KVM Continues Offering Much Better Performance Than VirtualBox

With the release earlier this month of Oracle VirtualBox 6.0, besides running some benchmarks of its VMSVGA 3D graphics support, I also ran some basic benchmarks to see how a similarly configured VM under both VirtualBox 6.0 with Linux KVM setup via virt-manager would compare for performance as we hit the end of 2018. This quick round of Linux virtualization tests was done on the AMD Ryzen Threadripper 2990WX system.

30 December 2018 - 32 Comments
GCC 9.0 Compiler Benchmarks Against GCC7/GCC8 At The End Of 2018

In early 2019 we will see the first stable release of GCC 9 as the annual update to the GNU Compiler Collection that is bringing the D language front-end, more C2X and C++ additions, various microarchitecture optimizations from better Znver1 support to Icelake, and a range of other additions we'll provide a convenient recap of shortly. But for those wondering how the GCC 9 performance is looking, here are some fresh benchmarks when benchmarking the latest daily GCC 9.0 compiler against GCC 7.4 and GCC 8.2 atop Clear Linux using an Intel Core i9 7980XE Skylake-X system.

28 December 2018 - 9 Comments
PGI 18.10 Compiler Benchmarks Against GCC 8.2, LLVM Clang 7.0

Given the recently release of the PGI 18.10 Community Edition compiler by NVIDIA, I was curious to see how the performance on the CPU is looking for this proprietary compiler on Linux. For those curious as well, here are some benchmarks of the PGI 18.10 C/C++ compiler against the GCC 8.2.0 and LLVM Clang 7.0 open-source compilers.

20 December 2018 - 7 Comments
VirtualBox 6.0 3D/OpenGL Performance With VMSVGA Adapter

With yesterday's release of Oracle VM VirtualBox 6.0, one of the most pressing changes for Linux guests is the use of the new VMSVGA 3D graphics device emulation by default. VMSVGA is the SVGA II graphics adapter from virtualization competitor VMware, but allows for the mature SVGA Linux graphics driver stack to be used. Here are some benchmarks looking at the OpenGL performance on VirtualBox 6.0.

19 December 2018 - 13 Comments
Core i9 7980XE vs. Threadripper 2990WX - The Pre/Post 2018 Linux Kernel Performance

Earlier this week I posted some benchmarks looking at the Linux kernel performance from the start to end of 2018 using an Intel Core i9 7980XE system. Here is the second part of that testing in looking at the same Linux 4.14 vs. 4.20 kernel benchmarking while putting the i9-7980XE performance side-by-side against the AMD Ryzen Threadripper 2990WX for seeing how its performance was impacted under the same kernel tests.

19 December 2018 - 10 Comments
A Look At The Linux Kernel Performance From 4.10 To 4.20

Here is a look at how the Linux kernel performance has evolved since Linux 4.10, which was released back in February of 2017, up through the current Linux 4.20 development cycle ahead of its debut at the end of December or early January. All of the Linux kernel benchmarks were done on the same venerable Intel Core i7 5960X system.

26 November 2018 - 13 Comments
Benchmarking The Work-In-Progress Spectre/STIBP Code On The Way For Linux 4.20

Due to the performance fallout from the introduction of STIBP for cross-hyperthread Spectre Variant Two mitigation in the Linux 4.20 kernel, the stable Linux kernels are reverting those patches after originally being quickly back-ported to those branches. For Linux 4.20, STIBP on by default for all processes remain in place until the revised STIBP code is ready for merging that is still expected to happen before the stable Linux 4.20 debut in about one month's time. Here are some initial benchmarks of those preliminary improvements.

23 November 2018 - 2 Comments
AMD AOCC 1.3 Compiler Benchmarks vs. GCC 8.2 vs. LLVM Clang 7.0

Earlier this month marked the release of the AMD Optimizing C/C++ Compiler 1.3 (AOCC 1.3) with a re-base to the LLVM 7.0 code-base, enhanced loop optimizations, better vectorization, code generation, integration of the optimized AMD Math Library, and other enhancements. Here are some fresh benchmarks against AMD AOCC 1.3 against LLVM Clang 7.0 upstream as well as GCC 8.2.0.

20 November 2018 - 20 Comments
The Spectre/Meltdown Performance Impact On Linux 4.20, Decimating Benchmarks With New STIBP Overhead

As outlined yesterday, significant slowdowns with the Linux 4.20 kernel turned out to be due to the addition of the kernel-side bits for STIBP (Single Thread Indirect Branch Predictors) for cross-HyperThread Spectre Variant Two mitigation. This has incurred significant performance penalties with the STIBP support in its current state with Linux 4.20 Git and is enabled by default at least for Intel systems with up-to-date microcode. Here are some follow-up benchmarks looking at the performance hit with the Linux 4.20 development kernel as well as the overall Spectre and Meltdown mitigation impact on this latest version of the Linux kernel.

17 November 2018 - 60 Comments
A Look At The GCC 9 Performance On Intel Skylake Against GCC 8, LLVM Clang 7/8

With GCC 9 embarking upon its third stage of development where the focus ships to working on bug/regression fixes in preparation for releasing the GCC 9.1 stable compiler likely around the end of Q1'2019, here is a fresh look at the GCC 9 performance with its latest development code as of this week compared to GCC 8.2.0 stable while using an Intel Core i9 7980XE test system running Ubuntu Linux. For good measure are also fresh results from LLVM Clang 7.0 stable as well as LLVM Clang 8.0 SVN for the latest development state of that competing C/C++ open-source compiler.

13 November 2018 - 15 Comments
The Performance Impact Of Spectre Mitigation On POWER9

Over the past year we have looked extensively at the performance impact of Spectre mitigations on x86_64 CPUs but now with having the Raptor Talos II in our labs, here are some benchmarks to see the performance impact of IBM's varying levels of Spectre mitigation for POWER9.

11 November 2018 - 16 Comments
A Look At The AMD EPYC Performance On The Amazon EC2 Cloud

Of the announcements from yesterday's AMD Next Horizon event, one that came as a surprise was the rolling out of current-generation EPYC processors to the Amazon Elastic Compute Cloud (EC2). Available so far are the AMD-powered M5a and R5a instance types to offer Amazon cloud customers more choice as well as being priced 10% lower than comparable instances. Here are some initial benchmarks of the AMD performance in the Amazon cloud.

7 November 2018 - 9 Comments
The Many New Features of The Linux 4.20 Kernel

With Linus Torvalds having just released Linux 4.20-rc1, here is our original feature overview looking at the major changes merged over the past two weeks for this new kernel. The Linux kernel will be ending 2018 on a high note with this kernel bringing more than 350 thousand lines of new code!

4 November 2018 - 6 Comments
Intel Core i9 9900K Spectre Mitigation Benchmarks

One of the benefits with the recently launched Core i9 9900K is hardware-based mitigations for Meltdown and L1TF/Foreshadow vulnerabilities. but mitigations are still needed for the other Spectre vulnerabilities. In this article is a look at the performance impact of still needing generic Retpolines via IBPB IBRS firmware for Spectre V2 and Speculative Store Bypass disabling (SSBD) for Spectre V4.

31 October 2018 - 7 Comments
Phoronix Test Suite 8.2 Released With Official Docker Benchmarking Image, New Testing Improvements

Phoronix Test Suite 8.2.0-Rakkestad is officially shipping today as the latest quarterly feature release to our open-source, cross-platform automated benchmarking software. In addition to the Phoronix Test Suite 8.2 itself, there is the first official release of the newly-introduced "phoronix/pts" Docker image on Docker Hub for easily carrying out the benchmarks with the pre-seeded image.

11 September 2018 - 9 Comments
A Look At The Linux Graphics/Gaming Performance With GNOME 3.30 X.Org/Wayland

Given last week's big GNOME 3.30 release I was eager to test the updated desktop environment with its Mutter compositor improvements on Wayland as well as seeing how its performance under the conventional X.Org Server. Here are some of these benchmarks of various graphics applications and games tested under both GNOME 3.28.3 and GNOME 3.30.0 with both Wayland and X.Org sessions.

10 September 2018 - 34 Comments
The Performance Cost Of Spectre / Meltdown / Foreshadow Mitigations On Linux 4.19

One of the most frequent test requests recently has been to look at the overall performance cost of Meltdown/Spectre mitigations on the latest Linux kernel and now with L1TF/Foreshadow work tossed into the mix. With the Linux 4.19 kernel that just kicked off development this month has been continued churn in the Spectre/Meltdown space, just not for x86_64 but also for POWER/s390/ARM where applicable. For getting an overall look at the performance impact of these mitigation techniques I tested three Intel Xeon systems and two AMD EPYC systems as well as a virtual machine on each side for seeing how the default Linux 4.19 kernel performance -- with relevant mitigations applied -- to that of an unmitigated kernel.

30 August 2018 - 29 Comments
Benchmarks Of Intel's Latest Linux Microcode Update

With all of the confusion last week over Intel's short-lived CPU microcode license change that forbid benchmarking only for them to change it a short time later -- to a much nicer license in that the microcode files can be easily redistributed and don't curtail it in other manners (and also re-licensing their FSP too), here are some performance benchmarks when trying out this latest Intel microcode on Linux.

27 August 2018 - 23 Comments
Quickly & Easily Running Benchmarks On Docker With "phoronix/pts"

Making the Phoronix Test Suite even easier to use for container benchmarking, on Docker Hub now is the phoronix/pts image for easily carrying out Docker tests with a fully-standardized, performance-optimized user-space stack with many of the popular test profiles pre-seeded on the disk and is ready to begin benchmarking out-of-the-box.

24 August 2018 - 18 Comments
The Impact Of The CPU Frequency Scaling Governor On AMD Threadripper 2990WX Linux Performance

One of many test requests we have received concerning the AMD Threadripper 2 Linux performance was to look at the impact of the different CPU frequency scaling governors, particularly for the 32-core / 64-thread Ryzen Threadripper 2990WX. Here are those CPUFreq governor benchmarks for those interested in squeezing slightly better performance out of your HEDT system by changing how aggressively or not the system is shifting power states to higher frequencies.

21 August 2018 - 9 Comments
The Performance Hit For A Xeon-Backed Ubuntu Linux VM With L1TF / Foreshadow Patches

Last week L1 Terminal Fault (a.k.a. L1TF and Foreshadow) was made public as the latest set of speculative execution vulnerabilities affecting Intel processors. This Meltdown-like issue was met by same-day Linux kernel patches for mitigating the problem and does introduce another performance penalty but in this case is at least only limited to virtual machines. Last week I posted some initial L1TF-mitigated KVM-based VM benchmark results using a Core i7 CPU but the results for sharing today are using a much more powerful dual Xeon server.

20 August 2018 - 18 Comments
Linux Scaling Benchmarks With The AMD Threadripper 2990WX In Various Workloads

While yesterday were the benchmarks showing how Linux games struggle to scale past a few CPU cores/threads, in this article is a look at the scaling performance of various applications/workloads under Linux up to 64 threads using the AMD Threadripper 2990WX. Here's a look at how the Linux performance changes in a variety of applications from one to sixty-four threads with this new HEDT processor.

17 August 2018 - 31 Comments

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