4 ms·
I wonder how comparable Geekbench actually is across different CPU architectures and operating systems though? Linus Torvalds is quoted here: https://www.realw
by p1necone 7y ago
I wonder how comparable Geekbench actually is across different CPU architectures and operating systems though?
Linus Torvalds is quoted here: https://www.realworldtech.com/forum/?threadid=185109&curpostid=185132 https://www.realworldtech.com/forum/?threadid=185109&curpost... as saying that Geekbench 4.0 shouldn't be treated as a valid comparison between desktops/laptops and phones. (However this review used Geekbench 5.0 - not sure what differences there are).
- berti 7y agoSpecint benchmarks conducted by Anandtech show the A13 going toe-to-toe with the 9900K [0], although x86 still has a decent lead for floating point. [0] https://www.anandtech.com/show/14892/the-apple-iphone-11-pro-and-max-review/4 https://www.anandtech.com/show/14892/the-apple-iphone-11-pro... (scroll down to the 2nd last plot, look at the right half)
- p1necone 7y agoDo mobile chips focus less on floating point for some reason? Could that explain the seemingly massive difference in perf/watt?
- ip26 7y agoFloating point tends to matter for classic 'number crunching' workloads- crypto, media encoding, anything to do with modeling the physical world, image processing, AI. Phones tend towards 'control flow', e.g. display an interface, accept a user input, communicate with a server, display information... and media decoding & gps both have dedicated hardware. FP workloads can be incredibly power hungry, so it's fortunate mobile devices mostly manage to avoid them. But any chip with an FP unit is going to shut it off when running integer code.
- wtallis 7y agoCrypto doesn't do floating point. Media transcoding does SIMD, but not usually not floating point.
- ip26 7y agoFair enough wrt media. However SIMD e.g. MMX is done in the floating point unit (https://softpixel.com/~cwright/programming/simd/mmx.php https://softpixel.com/~cwright/programming/simd/mmx.php) I thought bitcoin mining was floating point, and that was why GPUs were so adept.
- Dylan16807 7y agoMMX is obsolete. SSE/AVX has its own set of registers. It can do floating point and integer operations. It would not be correct to refer to it as a floating point unit. GPUs are good at mining because they can do so many calculations in parallel. They're just as capable of integer operations as the SIMD units on a CPU.
- wtallis 7y agoMMX was integer SIMD that re-used the FPU register file, but was not doing floating-point operations.
- xxs 7y agoCrypto stuff never uses floating point. It might have built-in instructions like AES-NI, though. In the test geekbench consider that - integers ones[0] and definitely not floating point. Media encoding tend not to use floating point, either. (decoders tend to be built-in in the GPUs with designated hardware, so testing on CPU is quite pointless) [0]: https://www.geekbench.com/doc/geekbench5-cpu-workloads.pdf https://www.geekbench.com/doc/geekbench5-cpu-workloads.pdf
- saagarjha 7y agoMost things on iOS tend to be dynamically linked these days.
- why_only_15 7y agoYeah, "statically linked" is a bizarre thing to say about iOS. I believe the only statically linked code on iOS is dyld itself. It's not possible to make a statically linked app on iOS, and certainly all the number crunching routines (and compression etc.) are dynamically linked. Maybe geekbench doesn't link them and does it in-process? But you would see the same effect on PCs then.