3 ms·

7-zip and x264 make almost perfect use of additional cores, so it makes sense that a quadcore beats a dualcore. (aside: I rather wish that Phoronix actually men

by brigade 14y ago

7-zip and x264 make almost perfect use of additional cores, so it makes sense that a quadcore beats a dualcore. (aside: I rather wish that Phoronix actually mentioned how much a given test benefits from multiple threads, single-threaded tests are presented next to multithreaded tests when comparing chips with different architectures and core counts without any comment or recognition.) Additionally, x264 is heavily optimized for x86 and nowhere near as much for ARM. 7-zip is probably similar. For floating point, A15 has double the execution resources as A9 (two symmetric floating point pipelines each capable of a FMA per cycle) so that's no surprise to me.

ajross 14y ago
Exynos-5, OMAP and Atom D5xx are all dual-core CPUs. And they all get about the same performance per clock in those tests. I don't think parallelism is a determiner -- I went with "cache-bound" as my guess. And again, this is a spot where I'd really like to see a comparison with something other than Pine Trail. One assumes the L3 on Ivy Bridge would be a big help.
- brigade 14y ago
  The Calexia Highbank Nodes are quad core. Relative to the OMAP4 tested, Exynos 5 has a 1.4x higher clock but 1.9x better 7-zip performance and 2.3x better x264 performance. For reference, A15 has double the vector execution resources as A9 in addition to adding out of order execution. Integer execution resources remain the same (two symmetric pipelines) but gains triple issue, wider out of order, and the potential of two load/store per cycle. So simple integer heavy workloads aren't expected to be incredibly faster from A9, just the ~40% ARM quotes and these tests back up. Atom D5xx has two hyperthreaded cores, and hyperthreading does help a lot for x264 at least. IIRC when I tested on a single-core Atom, the hyperthreading gave x264 a 1.6x boost.

by brigade 14y ago

ajross 14y ago

Exynos-5, OMAP and Atom D5xx are all dual-core CPUs. And they all get about the same performance per clock in those tests. I don't think parallelism is a determiner -- I went with "cache-bound" as my guess. And again, this is a spot where I'd really like to see a comparison with something other than Pine Trail. One assumes the L3 on Ivy Bridge would be a big help.

brigade 14y ago
The Calexia Highbank Nodes are quad core. Relative to the OMAP4 tested, Exynos 5 has a 1.4x higher clock but 1.9x better 7-zip performance and 2.3x better x264 performance. For reference, A15 has double the vector execution resources as A9 in addition to adding out of order execution. Integer execution resources remain the same (two symmetric pipelines) but gains triple issue, wider out of order, and the potential of two load/store per cycle. So simple integer heavy workloads aren't expected to be incredibly faster from A9, just the ~40% ARM quotes and these tests back up. Atom D5xx has two hyperthreaded cores, and hyperthreading does help a lot for x264 at least. IIRC when I tested on a single-core Atom, the hyperthreading gave x264 a 1.6x boost.