Geekbench scores are starting to pour in for the new models. When looking at Geekbench scores, you have to be sure you are comparing 32-bit mode tests to other 32-bit mode tests and 64-bit tests to other 64-bit tests.
I took the first ten 32-bit Geekbench scores for each model and averaged them. Looking strictly at 32-bit scores, here are the results:
2.40GHz Core i5: 4753
2.53GHz Core i5: 4964
2.66GHz Core i7: 5429
So, looking strictly at CPU and memory performance (what Geekbench measures)....
The 2.53GHz Core i5 has a 5.2% faster clock speed than the 2.40GHz Core i5 but in Geekbench testing the 2.53GHz Core i5 is only 4.3% faster than the 2.40GHz Core i5. If you equip the 2.40GHz Core i5 with a 500GB 5400rpm drive, the price difference is only $100. That 5.1% price difference buys you 4.3% better performance and no difference in video memory.
The 2.66GHz Core i7 has a 9.8% faster clock speed than the 2.40GHz Core i5 and in Geekbench testing the 2.66GHz Core i7 is 12.5% faster than the 2.40GHz Core i5. If you equip the 2.40GHz Core i5 with a 500GB 5400rpm drive, the price difference is $300. That 13.7% price difference buys you 12.5% better performance AND double the video memory.
The 2.66GHz Core i7 has a 4.9% faster clock speed than the 2.53GHz Core i5 and in Geekbench testing the 2.66GHz Core i7 is 8.6% faster than the 2.53GHz Core i5. The price difference between those two is $200. That 9.1% price difference buys you 8.6% better performance AND double the video memory.
As you can see, the Core i7 is definitely faster. And not just because it has a faster clock speed.
The (so far) "missing link" is how much of a difference the Core i7 model's additional graphics memory will make for applications that take advantage of it. Me, I use Aperture 3 heavily, along with some Photoshop. Both of those apps love extra video RAM (and are CPU intensive anyway) so I have ordered the Core i7. My current MacBook Pro (2.2GHz Core 2 Duo) is 3 years old. If I keep the Core i7 just as long, the $200-$300 price difference amortized over 36 months works out to $5-$8 per month. Chump change considering the additional speed. And, in 3 years, the Core i7 will net a higher resale value too.
Each person has to decide which model makes sense for them. But I think the 12.5% performance difference between the top of the line Core i7 and the bottom of the line Core i5 is significant enough to justify the money. Particularly given the upside potential for OpenCL and graphics due to double the video memory.
Lastly, to help put these figures in perspective, here are the Geekbench scores from two of my current Macs:
MacBook Pro 2.2HGz Core 2 Duo: 3110
Mac Pro 2 x 2.66GHz Xeon (four cores): 5628
That's a Mac Pro 1,1 model. A large, heavy, power hungry chunk of aluminum. Granted, it's also about 3 years old but look at that score and compare it to the new 2.66 Core i7. My new MacBook Pro is almost as fast as my Mac Pro! Freaking awesome!
EDIT: BTW, I ordered through my employer's employee purchase plan site. The discount on the more expensive models is slightly better. So my actual cost difference between the 2.40GHz Core i5 (with 500GB 5400rpm drive) and the 2.66GHz Core i7 is 11.8%. 11.8% more expensive to get 12.5% better performance. A no brainer for me.
Mark
