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iPhone XS is faster than iMac Pro on Speedometer 2.0 https://twitter.com/dhh/status/1043277162676072449 https://twitter.com/dhh/status/1043277162676072449 What

by k_bx 8y ago

iPhone XS is faster than iMac Pro on Speedometer 2.0 https://twitter.com/dhh/status/1043277162676072449 https://twitter.com/dhh/status/1043277162676072449 What makes you say it's closer to Intel U?

StillBored 8y ago
I would hesitate to draw conclusions about the general ability of the processor from a browser interactivity benchmark running on two differing OS's, with two likely differing browser builds, etc. Apple obviously spends a lot of time optimizing graphical interactivity/safari performance on the iphone and its shown for years. It might be interesting to try the same version of firefox on both platforms... or just a broader set of benchmarks. Its really too bad that no one has managed to get a stock linux running on an iphone....
- k_bx 8y ago
  The point I am making in this thread is that they are comparable, I never recommended drawing general conclusions.
hajile 8y ago
The slowest iMac Pro has a max clockspeed of 4.2GHz. The fastest has a max clockspeed of 4.5GHz. The max clockspeed of the A12 is 2.49Ghz. What magic allows Apple to get an almost 200% IPC boost? If that kind of performance improvement is actually possible in the general case, then Apple should exit the consumer market and start selling their chips to everyone. They'd make way more money than they do now. If something in chip design seems too good to be true, it is.
- k_bx 8y ago
  This is what a lot of people including myself are actually expecting, yes. The most interesting part is that the test is quite real world, not some microbenchmark. It runs to-do list app implemented with modern popular frameworks like Angular.
  - hajile 8y ago
    JS doesn't make a good general benchmark and speedometer is a bad benchmark in particular for that kind of test. The test itself is basically just writing a tiny todoMVC in a dozen different frameworks. Any one of those sub-tests would fit in only a couple MB of cache (for example, the React todo source is around 550 lines in total). An i7-8650U has a max clockspeed of 4.2GHz, so for short bursts of single-core processing where everything fits in cache, performance can definitely come close to that Xeon (there's a reason why people buy the Xeon instead of the U-series chip though) JS uses only 32-bit integers and 64-bit floats and executes on a single core (JS has typed arrays, but they certainly aren't going to be used in those kinds of frameworks). The power of modern x86 architectures is completely bypassed in that kind of test. A huge amount of the size and TDP an x86 core (I'd guess the majority given the width) is tied up in vector units, but those go entirely unused in JS code (and the JS SIMD proposal was completely killed making that unlikely). What are the other 7 to 17 Xeon cores doing during that benchmark? 30-50% of the TDP in these chips goes entirely to the interconnects because the hardest part of scaling chip design stopped being the actual core a long time ago. https://ark.intel.com/products/124968/Intel-Core-i7-8650U-Processor-8M-Cache-up-to-4-20-GHz- https://ark.intel.com/products/124968/Intel-Core-i7-8650U-Pr... https://browserbench.org/Speedometer2.0/ https://browserbench.org/Speedometer2.0/

by k_bx 8y ago

iPhone XS is faster than iMac Pro on Speedometer 2.0 https://twitter.com/dhh/status/1043277162676072449 https://twitter.com/dhh/status/1043277162676072449 What makes you say it's closer to Intel U?

StillBored 8y ago

I would hesitate to draw conclusions about the general ability of the processor from a browser interactivity benchmark running on two differing OS's, with two likely differing browser builds, etc. Apple obviously spends a lot of time optimizing graphical interactivity/safari performance on the iphone and its shown for years. It might be interesting to try the same version of firefox on both platforms... or just a broader set of benchmarks. Its really too bad that no one has managed to get a stock linux running on an iphone....

k_bx 8y ago
The point I am making in this thread is that they are comparable, I never recommended drawing general conclusions.

hajile 8y ago

The slowest iMac Pro has a max clockspeed of 4.2GHz. The fastest has a max clockspeed of 4.5GHz. The max clockspeed of the A12 is 2.49Ghz. What magic allows Apple to get an almost 200% IPC boost? If that kind of performance improvement is actually possible in the general case, then Apple should exit the consumer market and start selling their chips to everyone. They'd make way more money than they do now. If something in chip design seems too good to be true, it is.

k_bx 8y ago
This is what a lot of people including myself are actually expecting, yes. The most interesting part is that the test is quite real world, not some microbenchmark. It runs to-do list app implemented with modern popular frameworks like Angular.
- hajile 8y ago
  JS doesn't make a good general benchmark and speedometer is a bad benchmark in particular for that kind of test. The test itself is basically just writing a tiny todoMVC in a dozen different frameworks. Any one of those sub-tests would fit in only a couple MB of cache (for example, the React todo source is around 550 lines in total). An i7-8650U has a max clockspeed of 4.2GHz, so for short bursts of single-core processing where everything fits in cache, performance can definitely come close to that Xeon (there's a reason why people buy the Xeon instead of the U-series chip though) JS uses only 32-bit integers and 64-bit floats and executes on a single core (JS has typed arrays, but they certainly aren't going to be used in those kinds of frameworks). The power of modern x86 architectures is completely bypassed in that kind of test. A huge amount of the size and TDP an x86 core (I'd guess the majority given the width) is tied up in vector units, but those go entirely unused in JS code (and the JS SIMD proposal was completely killed making that unlikely). What are the other 7 to 17 Xeon cores doing during that benchmark? 30-50% of the TDP in these chips goes entirely to the interconnects because the hardest part of scaling chip design stopped being the actual core a long time ago. https://ark.intel.com/products/124968/Intel-Core-i7-8650U-Processor-8M-Cache-up-to-4-20-GHz- https://ark.intel.com/products/124968/Intel-Core-i7-8650U-Pr... https://browserbench.org/Speedometer2.0/ https://browserbench.org/Speedometer2.0/