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Ubuntu 12.04 ARM Performance Becomes Very Compelling
- justincormack 15y agoWell the hardfloat stuff was clearly worthwhile, but some meaningful benchmarks against x86 would be more useful. My ARM machines are all faster than my terrible Atom, but a lot slower than anything modern for cpu intensive benchmarks.
- agrover 15y agohow long does it take to compile the linux kernel?
- av500 15y agoIt takes "ages", but that is mainly due to the very slow mass storage speed that current ARM SoCs feature. Mobile phones and development boards like the Pandaboard use SD cards as mass storage and SD cards can be very slow when not used for typically linear read/write operations in your digital camera
- justincormack 15y agoI have an ssd on one of my machines, which helps but that is a slower softfloat single core box, so it still takes ages.
- anoother 15y agoDo you have any data to back this up? I have compiled kernels on an ARMv5 device off a (I believe PCI-e-hosted) 7200rpm SATA hard disk, and it _is_ slow.
- av500 15y agoI have only anecdotal evidence from people that are masochistic enough to compile their stuff natively, I prefer to cross-build.
- dsr_ 15y agoFor reference, this is the same CPU as the Galaxy Nexus, run at the same clockspeeds.
- newman314 15y agoThis particular set of benchmarks are misleading as more of the performance comes from a faster CPU clock speed. For a more accurate feel, look at the middle set of numbers. That said, hardfp looks to be a definite gain over softfp and really should have been deployed by distributions when the Cortex-A8 generation of processors became available.
- av500 15y agoThere are very few hardfp benchmarks that really compare just this feature and leave the rest of the system identical. E.g. comparing Debian armv5 with floating point emulation vs Ubuntu armv7hf of course yields a huge gain, but that mainly is not due to the fact that floating point values are now passed in fp registers. If SW relies heavily on passing a handful of floating point values in function calls, it should be rewritten to use NEON/SIMD on ARM - and then all you pass is a pointer to the data, regardless of the calling convention. And once you move to writing the mission critical stuff in assembly, you can chose your own calling convention for subroutines as you see fit anyway.
- DarkShikari 15y agoA lot of applications used on ARM may still be crippled due to lack of NEON assembly code. Many number-crunching applications, like compression, have lots of MMX/SSE SIMD on x86, but no NEON, and will likely be slow on ARM until they do.
- nextparadigms 15y agoWhat do you mean? All dual core ARM chips and above (except Tegra 2) have NEON. Also all 1 Ghz and above Snapdragon chips.
- newman314 15y agoMost smartphones now are armv7 and have been for the last 2 years or so. I don't see an issue with a baseline being set for armv7+vfp+neon being a minimum processor feature set going forward for mobile devices (phones & tablets)
- nextparadigms 15y agoCortex A15 and DDR3 for ARM should really start to make the ARM architecture very compelling for (low-end) laptops with very high battery life. And they're both arriving this year.