This article explains the cores, and hyper threading aspects of both:
Basically if you want the best performance go for the i7
I believe (but may be wrong) Adobe CS5 takes advantage of the MacBook Pro's 64 bit processing but doesn't use hyper-threading.
What is the major difference between the Core 2 Duo and Core i5/i7? Simple - Core 2 Duo has 2 processor core, which can process 2 threads. Core i5 or Core i7 has also 2 processor cores, but thanks to Intel Hyper-threading technology, it can process 4 threads, which is roughly equivalent to having 4 virtual processing cores.
Also, for the Intel Core i5 and i7, there is a feature called Intel Turbo Boost technology that increase the speed of the processor. In certain cases, it is capable of taking a 2.66GHz MacBook Pro 15" all the way up to 3.33GHz to speed up your work.
~ Quote from Mr.Kant Knowledge Base
Thomas Matheu wrote:
Some basic questions:
I will do my best here.
- How many physical cores do the i5 and i7 have?
They both have two.
- I understand the i7 is capable of hyperthreading, and the i5 is not. It this correct?
And in real world, how many apps take advantage of hyperthreading? Specifically, does Adobe CS5 take advantage of hyperthreading?
At the moment CS5 (e.g. here Photoshop) does not scale well in performance with the number of cores present in the computer system, so I wouldn't really think multi-core a huge advantage with much of CS yet. Similarly, hyperthreading in CS5 tends not to be an advantage, and turning it off can for some systems and workloads improve performance.
I am spec'ing out a new MacBook Pro and wanna make sure I get the most possible processing power for my $$$ for my needs.
I myself went for 17" (superior display) with Core i5 (i.e. the base model on offer), and upgraded my RAM to 8GB myself. Later this year I may upgrade the HD to SSD. This is probably as good a performance setup as you can get for pro apps on OS X Snow Leopard right now using a MacBook Pro...some of the upgrade options are costly and only minor increments at best.
The Macbook Pro i5 does use hyperthreading. The iMac i5, however, does not.
But your software needs to be written to take advantage of these features. In the end, clock speed is still king. And even then, you never know (see next paragraph).
FWIW, I did a side-by-side comparison of Macbook and a Macbook Pro playing a YouTube HD video at Best Buy. The Macbook had the older Core Duo 2 processor and the 15" MacBook Pro had an i5 with hyperthreading enabled. Even though the MBP had four threads going (witnessed via Activity Monitor), playing back the 720p HD video required about 30% processor use while the Macbook C2D only needed 20%. (I had activity monitor open on both macs) Strange...
I remember when the core 2 duo's came out it was better than sliced bread. Well please tell me in the last three years what has changed in the common programs being run:CS5, logic, final cut, iwork-etc that make the iX's all that better? Sure they may save one 45 seconds in handbrake,etc. But for common folk who are not using the processor to streamline a serious hobby or career, are the core 2 duo's 'all that bad or useless or dead' as so many posters have said? I too went to bestbuy yesterday and streamed a 720p video on both the i5 and low end 13" and could see no difference. Everything seemed the same in real time.
If the software isnt written to use multi-threading and turbo boost, why pay the extra 600 bucks for it. It it's future proofing then in three or four years these i5's and i7 chipsets will be just as outmoded so-called as the core2duos are? And the 13" models in three years will probably be better than the 15 and 17 incheres of today? With the several hundered you saved it seems like not so much of a sacrifice. I dont know just a thought. I know I have been guilty of wanting and having the best when "I" not you, "I" never used close to what was available. Then three years down the line the new models had so much other cool stuff the future proofing meant nothing. Just sayin. To each their own.
The activity monitor is not a reliable gauge of how much actual load your processor is doing due to the fact that processors can dynamically clock up and down.
Your Core 2 Duo maybe running at max frequency (but loaded at 20%) while the Core i5/7 maybe running at minimum frequency but loaded to 30% (don't quote me on this, it's been a while since I went into Windows, but I think it's 800 MHz). The activity monitor load is a percentage of processor load BASED ON THE PROCESSOR FREQUENCY AT THAT MOMENT.
Software doesn't need to be written to take advantage of Turbo Boost or Hyperthreading. (Although rewriting software with Hyperthreading in mind will sometimes yield a performance boost)
For Turbo Boost, if the application is single-threaded, the processor will AUTOMATICALLY clock itself up above it's rated frequency (barring any thermal/power considerations).
For Hyperthreading, if the software can use 3 or more threads, Hyperthreading will have an advantage due to the fact that the front-end of the execution core of the processor already has instructions ready to go. The Core 2 Duo has to flush its front-end if there are any thread switches (slow and power inefficient). There is only a very small niche of doubly-threaded software where the Core 2 Duo performs similarly to a Core i5/i7 and certainly there are little if any disadvantages.
Message was edited by: AzN1337c0d3r
Above mentioned article is a bit confusing.
Desktop i5 may have 2 or 4 physical cores, usually 2 cores with hyperthreading, 4 cores -without.
Desktop i7 is 4 or 6 physical cores, all with hyperthreading.
Mobile i7 is 2 physical cores (with graphics) or 4 cores (without graphics). All with hyperthreading. 4 core i7 is not available in MBP.
Mobile i5 is 2 cores with graphics, also with hyperthreading.