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

Why do you think the i7 in the 13" MBP can have a higher clocked GPU than the i5?

mikethebigo

mikethebigo

macrumors 68020
Original poster
May 25, 2009
2,433
1,597
As far as I can tell, other than the i7 having a little bit more L3 cache, these processors are architecturally identical. The i7 is basically a higher clocked i5. So the Iris Pro GPU in the i7 is clocked at 1.2 GHz while the i5 is clocked at 1.05 GHz, and I can't tell why. Comparing Cinebench scores, the i7 does have about 10% better GPU performance which is consistent with these numbers.

So why is this the case? Is Intel artificially dropping the clock rate for the GPU on the i5? Or is it possible the i7 is a higher binned part and has a little more headroom because of thermal efficiency? Or maybe you guys know a better answer?

Thanks!
 
mikethebigo said:
So why is this the case?
Click to expand...
Err, product differentiation, maybe heard of it? :D

The i7 is a higher end chip, and thus it comes with higher clocks. Binning could be part of it, and also if the manufacturing yields are good enough the i5 might simply be lower clocked (artificially, you call it) out of the gate, again to be able to offer a range of products to customers.
 
Product differentiation alone seems like a strange answer though, especially since no one advertises GPU clock speeds in these systems and you have to go looking for it.

So all things physically are equal, but they just turn down the knob on the i5 just to charge less for it? I feel like there must be some kind of hardware difference to help explain it.
 
mikethebigo said:
So all things physically are equal, but they just turn down the knob on the i5 just to charge less for it? I feel like there must be some kind of hardware difference to help explain it.
Click to expand...

The GPU and CPU cores are siamese twins. If the CPU side won the silicon lottery and is capable of higher clocks, then it is likely the GPU side won the same lottery too.
 
curmudgeonette said:
The GPU and CPU cores are siamese twins. If the CPU side won the silicon lottery and is capable of higher clocks, then it is likely the GPU side won the same lottery too.
Click to expand...
So you think that's the deal? The i7 is a little higher on the silicone lottery/binning?
 
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