I was indeed wrong both dual i5 and i7 have hyperthreading.Unfortunately, good sir, you're wrong.
The i7 in the 13" is a dual-core. Which means it also has just 4 threads like the dual-core i5.
The number of threads only vary between quad-core i5s and quad-core i7s. Quad-core i5s have 4 cores and 4 threads, while quad-core i7s have 4 cores and 8 threads.
The i7 has 4mb instead of 3mb L cache though.
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Macbooks only come with i7 quadcores. I dont know of any haswell quadcore i5s for laptops.However, if you're comparing between a quad-core i5 and quad-core i7, there's a fundamental difference as the quad-core i5 has 4 threads, while the quad-core i7 has 8 threads. Generally, a quad-core i7 with 8 threads perform about 30-40% faster in hyper threaded tasks compared to a quad-core i5.
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My advice: Get 16gb of ram.Well, I will tell you what I would be using the machine for.
(...)
So is the 16GB of RAM better than upgrading to the i7 2.8GHZ CPU? And with the CPU, Does it boil down to just a 0.2GHz clockspeed difference? Or is there something fundamentally different with an i5 vs. and i7 CPU?