faster splitter

[Wyatt via Digitalmars-d]

On Tuesday, 31 May 2016 at 08:43:59 UTC, Chris wrote:
> On Monday, 30 May 2016 at 22:16:27 UTC, qznc wrote:
>>
>> And Desktop:
>>
>> ./benchmark.ldc
>>        std: 129 ±24    +40 (3121)  -17 (6767)
>>     manual: 129 ±31    +59 (2668)  -21 (7244)
>>       qznc: 112 ±14    +30 (2542)   -9 (7312)
>>      Chris: 134 ±33    +58 (2835)  -23 (7068)
>>     Andrei: 123 ±27    +53 (2679)  -18 (7225)
>>  (avg slowdown vs fastest; absolute deviation)
>> CPU ID: GenuineIntel Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz
>>
>> ./benchmark.dmd
>>        std: 157 ±31    +44 (3693)  -24 (6234)
>>     manual: 143 ±41    +73 (2854)  -28 (7091)
>>       qznc: 116 ±21    +35 (3092)  -14 (6844)
>>      Chris: 181 ±50    +74 (3452)  -38 (6510)
>>     Andrei: 136 ±38    +64 (2975)  -27 (6953)
>>  (avg slowdown vs fastest; absolute deviation)
>> CPU ID: GenuineIntel Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz
>
> Benchmark from desktop machine:
>
> DMD:
>        std: 164 ±34    +43 (4054)  -29 (5793)
>     manual: 150 ±41    +72 (2889)  -29 (7032)
>       qznc: 103 ±6     +42 ( 878)   -2 (9090)
>      Chris: 205 ±43    +81 (2708)  -29 (7232)
>     Andrei: 136 ±31    +53 (2948)  -22 (6977)
>  (avg slowdown vs fastest; absolute deviation)
> CPU ID: GenuineIntel Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz
>
> ===
>
> LDC:
>
>        std: 138 ±23    +35 (3457)  -18 (6360)
>     manual: 145 ±33    +45 (3748)  -27 (6181)
>       qznc: 105 ±7     +17 (2267)   -4 (7534)
>      Chris: 135 ±33    +56 (3061)  -23 (6882)
>     Andrei: 121 ±27    +52 (2630)  -18 (7301)
>  (avg slowdown vs fastest; absolute deviation)
> CPU ID: GenuineIntel Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz
>
> On my laptop Andrei's was the fasted (see post above).

Comparing the chips involved, could it be cache related?

3M cache; Andrei wins both:
http://ark.intel.com/products/75459/Intel-Core-i5-4200U-Processor-3M-Cache-up-to-2_60-GHz

4M cache; qznc wins DMD (and is faster than the LDC's best? 
What?); Andrei wins LDC:
http://ark.intel.com/products/43560/Intel-Core-i7-620M-Processor-4M-Cache-2_66-GHz

8M cache; qznc wins both:
http://ark.intel.com/products/65719/Intel-Core-i7-3770-Processor-8M-Cache-up-to-3_90-GHz
http://ark.intel.com/products/75122/Intel-Core-i7-4770-Processor-8M-Cache-up-to-3_90-GHz

Normally, I'd expect the 4200U to be similar to the desktop 
parts.  Unless...

Say, for the laptops (and I guess the desktops too, but it's more 
important in a mobile), did you verify the CPU frequency scaling 
wasn't interfering?

-Wyatt