Sidebar Sidebar
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Please explain diff b/w Core 2 and i5/i7

S

sfscott

macrumors member
Original poster
Oct 13, 2008
73
0
In real (not technical) terms, what does an i5 processor deliver or improve upon from a core2 duo? What is the difference between an i5 and an i7.

On a related note, should one infer that the GPU in the new 13" is a better GPU than the ones in the 15", or does the performance of the i5 make that a moot point?
 
Three pictures for you... I'll explain in my next post.
 

Attachments

  • Intel P55 Diagram.jpg
    Intel P55 Diagram.jpg
    239.1 KB · Views: 170
  • intel_g45_1.png
    intel_g45_1.png
    74.8 KB · Views: 124
  • intel_x58_1.gif
    intel_x58_1.gif
    34.5 KB · Views: 132
i5 just uses newer technologies such as 32nm manufacturing process and Hyper-Threading which will make it faster clock for clock.

It's hard to explain so you would understand it but i5 is up to 30% faster than similar C2D
 
Core i7

Intel X58 is the chipset that supports the high end i7 class CPU. This CPU is mostly found in Desktops. Also referred to as LGA 1366. The features are HyperThreading, Triple Channel Memory, 40x 2.0 PCIe lanes and the fast QPI.

Intel also has the i7 brand for socket LGA 1156, under the codename Lynnfield and Clarksfield. This is the CPU class you have in the MacBook Pros. These have Dual Channel and connect via DMI instead. Slower, but gets the job done. faster than the FSB.

Core i5

Same thing as Core i7 LGA 1156, except these lack the HyperThreading feature.

Core 2 Duo

Based off LGA775 chipset. They are much slower because of the bottlenecking FSB. Also, RAM is not connect directly to the CPU which makes things even slower. This is what 13" MacBook Pros carry.
 
I have a simular question that i felt that i shouldnt post a whole new thread about... But i was curious the difference between the I7 processor in the 15' inch macbook pros vs. the Imac I5 dual core model.
 
jav6454 said:
Core i7

Intel X58 is the chipset that supports the high end i7 class CPU. This CPU is mostly found in Desktops. Also referred to as LGA 1366. The features are HyperThreading, Triple Channel Memory, 40x 2.0 PCIe lanes and the fast QPI.

Intel also has the i7 brand for socket LGA 1156, under the codename Lynnfield and Clarksfield. This is the CPU class you have in the MacBook Pros. These have Dual Channel and connect via DMI instead. Slower, but gets the job done. faster than the FSB.

Core i5

Same thing as Core i7 LGA 1156, except these lack the HyperThreading feature.

Core 2 Duo

Based off LGA775 chipset. They are much slower because of the bottlenecking FSB. Also, RAM is not connect directly to the CPU which makes things even slower. This is what 13" MacBook Pros carry.
Click to expand...

That's true in desktop version...

Mobile versions have no difference other than clock speed and 1MB of cache in i7 if Clarksfield is excluded as it's not used in MBPs
 
Smarterchild said:
I have a simular question that i felt that i shouldnt post a whole new thread about... But i was curious the difference between the I7 processor in the 15' inch macbook pros vs. the Imac I5 dual core model.
Click to expand...

iMac's i5 and i7 are quad core while MBPs are dual core. MBPs' are manufactured with 32nm method which gives ~15% better performance clock for clock than 45nm in iMacs' does.

iMacs are still WAAAAY faster than MBPs
 
Hellhammer said:
That's true in desktop version...

Mobile versions have no difference other than clock speed and 1MB of cache in i7 if Clarksfield is excluded as it's not used in MBPs
Click to expand...

And slight more aggressive Turbo mode in i5s and disabled HyperThreading in i5s as well.

That is the selling point of any i7 class CPU. HT

Hellhammer said:
iMac's i5 and i7 are quad core while MBPs are dual core. MBPs' are manufactured with 32nm method which gives ~15% better performance clock for clock than 45nm in iMacs' does.

iMacs are still WAAAAY faster than MBPs
Click to expand...

Also true. Desktop versions of chips are usually 20-30% faster (personally experience number)
 
jav6454 said:
Core i7

Intel X58 is the chipset that supports the high end i7 class CPU. This CPU is mostly found in Desktops. Also referred to as LGA 1366. The features are HyperThreading, Triple Channel Memory, 40x 2.0 PCIe lanes and the fast QPI.

Intel also has the i7 brand for socket LGA 1156, under the codename Lynnfield and Clarksfield. This is the CPU class you have in the MacBook Pros. These have Dual Channel and connect via DMI instead. Slower, but gets the job done. faster than the FSB.

Core i5

Same thing as Core i7 LGA 1156, except these lack the HyperThreading feature.

Core 2 Duo

Based off LGA775 chipset. They are much slower because of the bottlenecking FSB. Also, RAM is not connect directly to the CPU which makes things even slower. This is what 13" MacBook Pros carry.
Click to expand...

The mobile i5's and i7's both have HyperThreading, as far as I can tell.
http://ark.intel.com/Compare.aspx?ids=47341,43560,43544

The only advantage of the i7 over the i5 is a 5% higher clock speed, and larger cache, which won't make much difference for most applications.

The i5/i7's use a different architecture than Core 2's, which makes them faster for the same clock speed. Part of that is improvements for existing instructions, and part of that is new instructions (SSE4.2) that require code optimized for them. In addition, Turbo Boost and Hyperthreading help give them a speed advantage over Core 2's.

Most applications are not CPU-bound, but if you are doing stuff like video editing, you will probably benefit most from a Core ix.
 
Wait,I thought the new i5 and i7 in the new MBP's were dual core?That's what I read,so there different from the quads core i5 and i7 in the iMac 27"ers?So why do they have the same name but are different?
 
There are a few differences:

  • Core iX has an integrated northbridge - It has faster access to memory. (Bringing it to parity with a design AMD has used for years.)
  • Core iX has an intgrated GPU. - Intel's forcing system builders to incorporate their graphics chip.
  • Core iX has a few new instructions, including encryption instructions - AES encryption performance can double, which is important if you encrypt a lot of content. (ie: full disk encryption, etc.)
  • Some Core iX chips have hyperthreading - They're still two cores, but the cores each can run two threads, for a total of four. This isn't the same as quad core, but it does let you run two cores more efficiently. (four cores can still do more work than a hyperthreaded dual core, since there are double the number of compute units with four cores.)
 
macgeek18 said:
Wait,I thought the new i5 and i7 in the new MBP's were dual core?That's what I read,so there different from the quads core i5 and i7 in the iMac 27"ers?So why do they have the same name but are different?
Click to expand...

Because Intel's naming system simply sucks! There are three kinds of i5, Arrandale which is for laptops (used in MBPs), Clarkdale which is for mainstream desktops and Lynnfield which is quad core and used in iMac.

http://en.wikipedia.org/wiki/Intel_Nehalem_(microarchitecture)#Variants
 
The i5 offers a "virtual" 2 cores to the operating system that allows for better use of multi-threaded code.

Additionally, the i5 has a memory controller integrated onto the CPU that gives much better transfer rates between subsystems.

In practical cases the i5 will be ~30% faster than the Core 2 clock for clock, however in highly threaded code (image or video manipulation, encoding, audio, etc) the difference will be higher, closer to ~60%.

The ONLY difference between the i5 and the i7 is the amount of cache it offers. The real world performance difference is around 5% between the i5 and i7.
 
Hellhammer said:
Because Intel's naming system simply sucks! There are three kinds of i5, Arrandale which is for laptops (used in MBPs), Clarkdale which is for mainstream desktops and Lynnfield which is quad core and used in iMac.

http://en.wikipedia.org/wiki/Intel_Nehalem_(microarchitecture)#Variants
Click to expand...


Same deal with i7.

i7 Bloomfield (Quad-Core high-end)
i7 Lynnfield (Quad Core mid end
i7 Gulftown (6-core High end)
i7 Arrandale (2 Core Mid-high)
i7 Clarksfield (Quad Core high-end)

The last two being laptop CPUs.
 
Opps, wrong word. I meant Quad Core.

I am looking to get a main computer for photo editing for college and im thinking of either the 15' I7 MBP with 8gb ram and HD and anti glare screen versus the Imac quad core I7 with 8gb ram. Im thinking the MBP will be enough for computer editing though college and then i could eventually just get a external monitor (27 inch) and get a Mac pro during the end of college.

My thought, Ipad 64gb for a mobile book for schooling and note taking along with a Macbookpro 15inch. Instead of a Pimped out Imac that i wont need dual core quite yet on and wait till i acutally go into the proffession.
 
They should have named them m5 and m7 for laptops, and the m5 shouldn't have hyperthreading.
 
The iX chips should run cooler than core 2 chips. They are built on a smaller manufacturing process (32nm vs 45nm), and they presumably have better power management.
 
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom
Back