geekbench 13" MBP vs. 13" MBA riddle

prism

macrumors 6502a
Original poster
Dec 6, 2006
805
144
Ok, I have myself scratching my head on the geekbench results of the new entry level 13" MBA which are within 100 points range to those of the entry level 13" MBP.
If I am not mistaken, the MBA uses a low voltage 1.7 ghz i5, whilst the MBP has a 2.3 ghz i5. I also presume that both have turbo boost so what gives? I mean if a lower speed processor which is also lower voltage can produce results like this, its clearly superior to those of the MBP line which, mind you, are of the same generation!
Also if I am not mistaken, geekbench does not measure hd i/o speed so it cant be because the MBA uses flash.
Anyone with some real knowledge please enlighten me!
 

thunng8

macrumors 6502a
Feb 8, 2006
821
206
Ok, I have myself scratching my head on the geekbench results of the new entry level 13" MBA which are within 100 points range to those of the entry level 13" MBP.
If I am not mistaken, the MBA uses a low voltage 1.7 ghz i5, whilst the MBP has a 2.3 ghz i5. I also presume that both have turbo boost so what gives? I mean if a lower speed processor which is also lower voltage can produce results like this, its clearly superior to those of the MBP line which, mind you, are of the same generation!
Also if I am not mistaken, geekbench does not measure hd i/o speed so it cant be because the MBA uses flash.
Anyone with some real knowledge please enlighten me!
The low voltage chip has more aggressive turbo boost. I think it can boost from 1.7Ghz to 2.7Ghz, while the 2.3Ghz i5 can boost to 2.9Ghz. For a benchmark like Geekbench, it will mostly run at boosted speeds. for more intensive benchmarks which will heat up the CPU for longer periods, it is likely that ULV will not be able to turbo boost speed for long periods.

That being said, I think the ULV chip was using the 64 bit version of Geekbench. The 2.3Ghz i5 in the 13" MBP running the 64 bit version of geekbench gets close to 6500, so there is difference. The 2.7Ghz i7 MBP gets approx 7500 in 64 bit Geekbench.
 

prism

macrumors 6502a
Original poster
Dec 6, 2006
805
144
I think the ULV chip was using the 64 bit version of Geekbench. The 2.3Ghz i5 in the 13" MBP running the 64 bit version of geekbench gets close to 6500, so there is difference. The 2.7Ghz i7 MBP gets approx 7500 in 64 bit Geekbench.
That is very interesting, I was not aware of the significant score difference between 32 and 64!
 

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