Intel Core i5 6500: A Great Skylake CPU For $200, Works Well On Linux
Before getting to the performance results, a few words about Skylake Linux compatibility: as long as you're using a modern distribution with the very latest kernel, you should be fine. It's only with the Linux 4.3 kernel (to be officially released in a few weeks) that the Gen9 Skylake graphics are enabled by default rather than requiring an "experimental" kernel module switch, but some distributions like Ubuntu have already been patching their recent kernel builds with Skylake support enabled by default. With Linux 4.3 is where the initial Skylake audio support is also in place. It's possible to run with Skylake on distributions with older kernels from earlier in the year, but for the best support and performance you'll definitely want to be running the Linux 4.3 kernel as soon as possible.
For the best graphics support, Mesa 11.0 or even better is Mesa Git Master. However, even with the latest development code, only OpenGL 3.3 is currently exposed by Intel's open-source driver. They're working towards OpenGL 4.x compliance and almost to OpenGL 4.1, but they're not quite there yet. If you're interested in OpenCL, the latest open-source Beignet code has OpenCL 1.2 support for Skylake.
For this Core i5 6500 Linux benchmarking, a near-final development build of Ubuntu 15.10 x86_64 was used while manually switching over to the Linux 4.3 Git kernel. Unity was the default desktop, GCC 5.2.1 was the compiler, and Mesa 11.0.2 was running. This was also the same stack used on the other systems for comparison.
The Intel processors for this comparison included the:
- Intel Core i3 2120 as an old Sandy Bridge processor that's dual-core, has Hyper Threading, and runs up to 3.3GHz. Testing this CPU is fun for kicks and seeing how far Intel CPUs have evolved in the past few years.
- Intel Core i5 2500K as one of the most popular Sandy Bridge processors; as a reminder, it's quad-core with a max turbo frequency of 3.7GHz and base of 3.3GHz. The i5-2500K clock frequencies are just a little bit higher than the i5-6500's 3.2GHz base and 3.6GHz turbo.
- The Pentium G3258 as a low-end Haswell processor. That dual-core Haswell processor runs at 3.2GHz and sells for about $70.
- The Intel Core i5 4670 as a mid-range Haswell processor that through Internet retailers is still available and selling for about $230 USD. The i5-4670 is quad-core with a 3.4GHz base frequency and 3.8GHz turbo.
- The Core i7 4790K as the highest-end Core i7 Haswell Refresh processor. This $300+ processor is quad-core with Hyper Threading and has a 4GHz base frequency and 4.4GHz turbo.
- The Core i7 5775C as the socketed Broadwell CPU running at 3.3GHz with a 3.7GHz turbo for its four cores plus Hyper Threading.
- The Core i5 6600K as the $260 Skylake processor with with 3.5GHz base frequency and 3.9GHz turbo.
The AMD hardware tested for comparison were:
- The AMD A10-7850K Kaveri APU. The A10-7850K sells for about $130 these days and this quad-core 95 Watt (TDP) APU has a 3.7GHz base frequency and 4.0GHz turbo frequency.
- The AMD FX-8150 as an older Bulldozer CPU with eight cores and 3.6GHz clock frequency, which matches the turbo frequency of the Core i5 6500.
- The AMD FX-8370 as the closest priced competitor to the $200 Core i5 6500. The FX-8370 is selling for $190+ and is clocked at 4.0GHz with a 4.3GHz turbo.
All of these systems were running the Ubuntu 15.10 stack mentioned above. Common to the systems were using 8GB of DDR3/DDR4 memory in each system at a frequency that match the system's potential and 120GB Kingston SV30053 SSD.
Of course, all of the Linux benchmarking for this Intel/AMD comparison were done using the open-source Phoronix Test Suite benchmarking software. First up are the CPU tests followed by a few Linux OpenGL graphics tests and then also some performance-per-Watt metrics for this inaugural i5-6500 test.