Software Archives
GCC vs. LLVM Clang vs. AOCC Compilers On AMD Threadripper

Given recent improvements to AMD Zen (znver1) with LLVM, the new AMD AOCC 1.2 compiler release, and GCC 8.1 having premiered just weeks ago, here is a fresh look at the performance of six different C/C++ code compilers when testing the performance of the resulting binaries on an AMD Threadripper 1950X system.

23 May 2018 - 14 Comments
AMD AOCC 1.2 Code Compiler Offers Some Performance Benefits For EPYC

Last month AMD released the AOCC 1.2 compiler for Zen systems. This updated version of their branched LLVM/Clang compiler with extra patches/optimizations for Zen CPUs was re-based to the LLVM/Clang 6.0 code-base while also adding in experimental FLANG support for Fortran compilation and various other unlisted changes to their "znver1" patch-set. Here's a look at how the performance compares with AOCC 1.2 to LLVM Clang 6.0 and GCC 7/8 C/C++ compilers.

20 May 2018 - 5 Comments
GCC 8.1 vs. GCC 7.3 Compiler Benchmarks On Five AMD/Intel Linux Systems

With GCC 8.1 having been officially released last week, I have spent the past number of days running a variety of compiler benchmarks comparing this initial GCC8 stable release to the previous GCC 7.3 stable compiler release. Tests were done on five different Ubuntu 18.04 LTS Linux systems running very different AMD and Intel processors.

10 May 2018 - 15 Comments
Linux 4.17 Offers Some Promising Power-Savings Improvements

Of the many improvements to be found in the in-development Linux 4.17 kernel -- nicely summarized in our Linux 4.17 feature overview -- one of the features I've been anxious the most to begin benchmarking has been the reported power management improvements. Here are my initial power/performance tests of Linux 4.17 that for some systems is seeing a measurable drop in power usage, even in some cases under load while without sacrificing the performance.

15 April 2018 - 30 Comments
The Many Great Features & Changes Coming For The Linux 4.17 Kernel

Linus Torvalds is expected by the end of the day to release Linux 4.17-rc1, thereby marking the end of the two-week merge window that saw a lot of changes and new features land for Linux 4.17. Here is our original feature overview of the changes to be found in this next major release of the Linux kernel, which should premiere as stable by the middle of June.

15 April 2018 - 1 Comment
Linux 4.4 To 4.16 Kernel Benchmarks With AMD Ryzen Threadripper

This past weekend I posted some Linux 3.17 to Linux 4.16 kernel benchmarks using two older Intel hardware platforms and one of the most frequent requests to come in following that article were some AMD benchmarks looking at the Intel Linux performance going a ways back. Here are some test results from Linux 4.4 to 4.16 using an AMD Ryzen Threadripper 1950X system.

27 March 2018 - 7 Comments
Linux 3.17 To Linux 4.16 Kernel Benchmarks On Intel Gulftown & Haswell Hardware

Our latest benchmarking of the near-final Linux 4.16 kernel is checking on the performance of two Intel systems going back to the days of Linux 3.17, the oldest kernel that would successfully boot with the Ubuntu 18.04 user-space. Every major kernel release was tested as we see how the Linux kernel performance has evolved on these Haswell and Gulftown systems since October 2014.

25 March 2018 - 20 Comments
LLVM Clang 6.0 vs. 5.0 Compiler Performance On Intel/AMD Linux

Since last week's big release of LLVM 6.0 along with Clang 6.0, I have been carrying out some fresh compiler benchmarks of the previous Clang 5.0 to this new stable release that switches to C++14 by default, among many other changes to LLVM itself and this C/C++ compiler front-end.

14 March 2018 - 2 Comments
An Early Look At The Linux 4.16 Kernel Performance With AMD EPYC

A few days back I provided some fresh Linux 4.16 kernel benchmarks compared to recent stable kernel releases while also toggling the KPTI and Retpoline security features on Linux 4.16 Git for seeing the impact of the Spectre and Meltdown mitigation techniques on this latest kernel while using Intel Xeon hardware. For this latest round of tests is a similar comparison while using an AMD EPYC system.

10 March 2018 - 2 Comments
Bringing Open-Source, Automated Benchmarks To Windows 10 / Windows Server 2016

Moving forward the Phoronix Test Suite will be offering Microsoft Windows support that's at near feature parity to the automated, reproducible, open-source benchmarking support we have offered the past decade for Linux as well as BSD, macOS, and Solaris platforms. This is brand new, rewritten Windows support with a focus on Windows 10 x64 and Windows Server 2016.

8 March 2018 - 12 Comments
Benchmarking Amazon EC2 Instances vs. Various Intel/AMD CPUs

Given the recent performance changes following the Spectre/Meltdown CPU vulnerability mitigation and having just wrapped up some fresh CPU bare metal benchmarks as part of that testing as well as the recent AMD Raven Ridge launch, I've carried out a fresh round this week of benchmarks on various Amazon EC2 on-demand instance types compared to a number of bare metal Intel and AMD processors in looking at how the compute performance compares.

20 February 2018 - 12 Comments
A Look At The Plethora Of Linux 4.16 Kernel Features & Changes

After the lengthy Linux 4.15 kernel cycle, the past two weeks have marked the Linux 4.16 merge window. Yet again it's been another heavy feature period for the kernel. There is still a lot of mitigation work going on for most CPU architectures surrounding Spectre and also Meltdown, the open-source graphics drivers have continued getting better, various CPU improvements are present, the VirtualBox Guest driver was mainlined, and dozens of other notable changes for Linux 4.16. Take a look.

11 February 2018 - 5 Comments
AMD AOCC 1.1 Shows Compiler Improvements vs. GCC vs. Clang

A few days ago we found out that at the end of 2017 AMD quietly released their AOCC 1.1 C/C++ compiler. AOCC is AMD's compiler succeeding AMD Open64 that existed years ago as their optimized Fortran/C/C++ compiler for past CPU microarchitectures while the "AMD Optimizing C/C++ Compiler" is designed for current-generation Zen processors. Here are benchmarks of the new AMD AOCC 1.1 release compared to GCC 7, GCC 8, Clang 5.0, Clang 6.0, and Clang 7.0 SVN.

30 January 2018 - 13 Comments
Linux 4.0 To Linux 4.15 Kernel Benchmarks

Our latest in benchmarking the Linux 4.15 kernel is seeing how the performance has changed since Linux 4.0 and all subsequent releases on the same system. Here are those tests driven by curiosity, especially in light of the performance changes as a result of KPTI page table isolation and Retpoline additions.

24 January 2018 - 11 Comments
Benchmarking Retpoline-Enabled GCC 8 With -mindirect-branch=thunk

We have looked several times already at the performance impact of Retpoline support in the Linux kernel, but what about building user-space packages with -mindirect-branch=thunk? Here is the performance cost to building some performance tests in user-space with -mindirect-branch=thunk and -mindirect-branch=thunk-inline.

16 January 2018 - 5 Comments
Benchmarking Ubuntu's Low-Latency Kernel & Liquorix Post-Meltdown

A new Phoronix Premium member was hypothesizing in the forums whether Ubuntu's low-latency kernel would be performing better in the wake of the Kernel Page Table Isolation (KPTI) support in the kernel for fending off the Meltdown CPU vulnerability. With always aiming to deliver on test requests by premium members, I ran some benchmarks of the Ubuntu low-latency vs. generic kernels and I also tossed in the Liquorix kernel for benchmarking too.

14 January 2018 - 30 Comments
GCC 8.0 vs. LLVM Clang 6.0 On AMD EPYC

At the beginning of January I posted some early LLVM Clang 6.0 benchmarks on AMD EPYC while in this article is comparing the tentative Clang 6.0 performance to that of the in-development GCC 8.0. Both compilers are now into their feature freeze and this testing looked at the performance of generated binaries both for generic x86_64 as well as being tuned for AMD's Zen "znver1" microarchitecture.

13 January 2018 - 10 Comments
KPTI + Retpoline Linux Benchmarking On Old Laptops

Over the past week and a half of running many benchmarks looking at the performance impact of the Linux KPTI and Retpoline patches for Spectre and Meltdown mitigation, one of the most common test requests is some thorough benchmarks on older systems. Why that's important is with older (pre-Westmere) CPUs there isn't PCID (Process Context Identifier) support that's used by KPTI, which helps offset some of the performance loss. So for some test results to share today are two old ThinkPads from the Clarksfield and Penryn days compared to a newer Broadwell ThinkPad in looking at the performance difference.

11 January 2018 - 35 Comments
Benchmarking Linux With The Retpoline Patches For Spectre

While the Kernel Page Table Isolation (KPTI) patches were quick to land in the mainline Linux kernel for addressing the Meltdown CPU vulnerability, the "Retpoline" patches are still being worked on as the leading approach on the Linux side for dealing with the Spectre CPU vulnerability. The Retpoline patches are said to have little impact on performance, but here are our benchmarks of these kernel patches for seeing how they affect a variety of AMD and Intel systems.

8 January 2018 - 58 Comments
Linux KPTI Tests Using Linux 4.14 vs. 4.9 vs. 4.4

Yet another one of the avenues we have been exploring with our Linux Page Table Isolation (KPTI) testing has been looking at any impact of this security feature in the wake of the Meltdown vulnerability when testing with an older Linux Long Term Support (LTS) release. In particular, when using a kernel prior to the PCID (Process Context Identifier) support in the Linux kernel that is used to lessen the impact of KPTI.

4 January 2018 - 30 Comments
Initial Benchmarks Of The Performance Impact Resulting From Linux's x86 Security Changes

Over the past day you've likely heard lots of hysteria about a yet-to-be-fully-disclosed vulnerability that appears to affect at least several generations of Intel CPUs and affects not only Linux but also Windows and macOS. The Intel CPU issue comes down to leaking information about the kernel memory to user-space, but the full scope isn't public yet until the bug's embargo, but it's expected to be a doozy in the data center / cloud deployments. Due to the amount of interest in this issue, here are benchmarks of a patched kernel showing the performance impact of the page table isolation patches.

2 January 2018 - Add A Comment
LLVM Clang 6.0 Benchmarks On AMD's EPYC Yield Some Performance Benefits

With LLVM 6.0 being branched this week and that marking the end of feature development on this next compiler update before its stable debut in February, here are some benchmarks of the very latest LLVM Clang 6.0 compiler on AMD's EPYC 7601 32-core / 64-thread processor as we see how well the AMD Zen "znver1" tuning is working out.

2 January 2018 - 3 Comments
KVM Smokes VirtualBox On Initial AMD EPYC Linux Tests

I've been working on some AMD EPYC virtualization tests on and off the past few weeks. For your viewing before ending out the year are some initial VirtualBox vs. Linux KVM benchmarks for seeing how the guest VM performance compares.

30 December 2017 - 23 Comments

596 software articles published on Phoronix.