i7-2677M vs. i5-4250U

I've been trying to decide between these two refurbished MBA's:

Refurbished 11.6-inch MacBook Air 1.8GHz dual-core Intel Core i7 - Apple Store (U.S.)

and

Refurbished 11.6-inch MacBook Air 1.3GHz dual-core Intel Core i5 - Apple Store (U.S.)

and somebody told me that the 4th gen i5 1.3 Ghz would outperform the 2nd gen i7 1.8Ghz. I compared them on Intel's website, and though I know the i5 is the newer CPU, I still don't quite understand how it could be better than an i7 with hyperthreading and so much better specs. Can somebody explain this to me?

You have been advised correctly in that the latest i5 will outperform the older i7

Notebookcheck.net has good cpu comparisons based on benchmarks. You can also click through to see performance in certain applications

Mobile Processors - Benchmarklist - NotebookCheck.net Tech

Here's your i5
Intel Core i5 4250U Notebook Processor - NotebookCheck.net Tech

Here's your i7
Intel Core i7 2677M Notebook Processor - NotebookCheck.net Tech

Interesting results. I would expected them to be equal at best. Have to keep this in mind the next Mac Mini upgrade roles around.

Wman said:

and somebody told me that the 4th gen i5 1.3 Ghz would outperform the 2nd gen i7 1.8Ghz. I compared them on Intel's website, and though I know the i5 is the newer CPU, I still don't quite understand how it could be better than an i7 with hyperthreading and so much better specs. Can somebody explain this to me?

Click to expand...

When a new computer model is released...the cpu it uses (in most cases) is not the only thing that is improved. Things like:

- logic board architecture is improved (speedier)
- faster graphics hardware
- faster ram
- etc.

All contribute to how well (overall) an individual computer model will perform.

As far as the comparison of cpu's themselves. With every generation of cpu...each generation is improved. So it really shouldn't be that surprising that a 4th generation i5 cpu can outperform a 2nd gen. i7 cpu.

The performance difference between an i5 and an i7 of the exact same generation (same number of cores and same clockspeed) may not be that dramatic. For discussion's sake...maybe we're talking a difference of only 10-15%.

So it really isn't that difficult for an i5 cpu that is 2 generations newer...to be able to out perform an older i7 cpu.

Some additional info. The main differences between i5 and i7 cpus are:

- i7 cpu's generally have higher clock speeds (ghz)
- i7 cpu's generally have more cores (4 cores vs. 2 cores). You generally don't see many quad-core i5 cpu's (at least not in the Apple World).
- i7 cpu's generally have a greater cache
- i7 used to exclusively have "hyper-threading"

i5 vs i7 - Difference and Comparison | Diffen

But with multiple generations...newer i5's have faster clock speeds, newer i5's have hyper-threading, newer i5's have larger caches, etc. So basically...newer i5's can be better than older i7's.

Combine this with better logic board architecture, faster ram, etc....and it's really not that difficult for a newer computer with a newer generation i5...to beat the performance of a computer with an older generation i7.

- Nick

pigoo3 is your name a reference to Pigoons from Marget Atwood's Oryx and CRake?

Wman said:

pigoo3 is your name a reference to Pigoons from Marget Atwood's Oryx and CRake?

Click to expand...

Nope. Something completely different. Thanks for asking.

- Nick