The Basic Differences in Chips

First off, I should note that the Core i7 chip has what Intel calls a "turbo mode." That is, when it's not utilizing all of its cores, it can dynamically overclock itself up to 3.4GHz on whatever single core is in use. It can, as shown in this video, work in steps. So you get the turbo benefit when using some of the four cores in this iMac's chip, but you also get it when all cores are being partially used. For example, if four cores are running but only at a fraction of their total capacity (less then 100%), the cores can use that electrical/thermal overhead to overclock to varying degrees. This should theoretically make up for the difference between the two-core 3.06GHz chip and the hyperthreaded quad core chip at a base of 2.8GHz.

The other thing to realize about these newer Core i7 chips are that they have no northbridge—or bus—between the memory and CPU. The memory controller is built right into the processor, and there's a new tech called QuickPath interconnect which connects the cores in a point-to-point architecture. Core i7 supports triple-channel memory (which would use three banks at once), but this iMac only came loaded with two banks of RAM filled. Like our other iMac, that's a 2GB + 2GB arrangement.

Matt explains more about i7 here. (And yes, there are differences between i7 and i5, besides clock speed.)

*Note that this machine also had a faster ATI Radeon 4850 video card with 512MB of RAM (versus the 4670 card in the other iMac) which may have impacted performance in several apps. I have no idea which of these apps uses the GPU to accelerate its tasks under Snow Leopard. (For example, Preview may use it to help render JPGs faster, or it may not. Apple could not tell me. In Adobe After Effects, the Radeon series of cards apparently is not supported for OpenCL acceleration. )

Performance with Multithreaded Apps

In short, any task we tried that expressly was written to either a) take advantage of multiple cores, or, b) take advantage of multiple cores through Snow Leopard's multicore middleware, Grand Central Dispatch, were 2 to 3 times faster. (More on that here.) These results include:

• 64-bit versions of Geekbench, which focus on CPU and memory tests.
• Adobe After Effects benchmarks
• Opening 20 images of Tokyo Tower that are 2000x2000 pixels and 35MB each.

Impressive stuff, but honestly, those tests were kind of uninteresting to me. I mean, those tests don't really have any correlation to my daily computing use. So on a whim, after benchmarking, I tested Handbrake, the DVD ripping software I love. It, too, was freaking fast.

I know the app is multithreaded, but I did not know what level of optimization it was written for. I was blown away by a 3x speed multiplier with the i7. On the Core i7 iMac, it took 43 minutes to rip a DVD, Storm Riders, a surfing film from the '70s featuring Gerry Lopez (my favorite) and others. On the Core 2 Duo machine, it took 147 minutes! I know this is basically a DVD read test coupled with decoding and video conversion, but the results have me excited because this is a real task that takes my computer a long time to do, performed by a program that hasn't been revised in a year.

Performance With Single-Core Optimized Apps (Otherwise Known as Reality)

Unfortunately, there are still very few applications that take advantage of multiple cores directly or via Snow Leopard's GCD, not even video-based, let alone general purpose computing.

Photoshop CS4 on the Mac, which is not set up to handle multicore processors, showed almost less than a 3% improvement using the Driver Heaven benchmark. Basic tasks, like booting and shutdown, saw virtually none. Playing the 1080p Quicktime trailer of Avatar consistently showed that the i7 was using 3% less of its total CPU than the Core2Duo, but I wonder if that's a result of the faster graphics card kicking in using CoreCL. Xbench, the old program that does a more comprehensive job of benchmarking a system from disks to processors, showed almost no difference.

I think Xbench, which hasn't been updated in years, is a solid benchmark for that old program that you depend on but has been long abandoned or at least ignored by its developer.

These scores, again, are in relation to the top line 3.06GHz Core 2 Duo iMac we tested. Some benchmarks have come in from the web comparing the i7 to the i5. Here's one that claims a 30% jump using Geekbench. Now we know Geekbench likes and does well with more cores and is a synthetic CPU test. But if the i5 is 30% slower, and the i7 pulls even with the 3.06 GHz Core 2 Duo chip in single threaded activity—most day to day activity—does that mean the i5 is slower than the cheaper Core 2 Duo? Maybe. Probably not 30%, since Geekbench is strictly CPU/memory and likes more cores, and this stuff does not translate so literally in the real world. But we can assume the i5 will have 30% less jump from the top tier Core 2 Duos, translating into a mere 1.3X to 2X speed increase from last gen chips on programs that like cores.

Value

For the most part, in our review, I said that you should stick to the preconfigured options, upgrading to Apple's next recommended config before considering upgrades to the lower tier models. How does that advice change now that we've seen the i7? I don't know! I guess it depends if you're a betting man. If you think programs for Snow Leopard using GCD are coming, paying $200 to $500 bucks more from the top line Core 2 Duo chip for an i5 or i7 might make sense. The probability of you getting programs that can use those extra cores goes up if you are a graphics or video professional who expects to see support from Adobe, Apple, etc. (Apple already claims big jumps in Aperture that we weren't able to test.) Or if you rip a lot of DVDs! The rest of you? The Core 2 Duo stuff could be fine for today and fine for tomorrow. But the Core i7 is not worse for today and will definitely be faster tomorrow. It just costs more.

Me personally? I'd opt for the Core i7. I just might wait til the new iMacs refresh a bump and the i7 is cheaper and part of a standard build. But I'm patient like that.

[iMac Review]

* The CPU performance is Faster by 40-70%
* The fillrate* is 3x to 4x higher
* Texture effects and filters are about 10x faster

Keep in mind that it's also running OpenGL1.x on the benchmark test, and iPhone 3GS can run OpenGL 2.x. The upside is that when games do get optimized or developed for OpenGL 2.x, that's when your old phone will no longer be able to play them, or at least play them with better graphics. It's pretty obvious once you play with the phone that it's rendering your old games much faster, but it's good to get it in quantitative form. [glbenchmark via Extremetech via Ubergizmo]

The new maximum component score is a 7.9. Microsoft has (and will continue to) raise the cap as new hardware components come out. If a current component score is a 5.6 under Vista, it will continue to be around a 5.6 (give or take) unless it was subject to various tweaks and feedback changes Microsoft took when adjusting the index, such as new disk tests.

For gaming...

...scores in the 6.0 to 6.9 range to support DX10 graphics and deliver good frames rates at typical screen resolutions (like 40-50 frames per second at 1280x1024). In the range of 7.0 to 7.9, we would expect higher frame rates at even higher screen resolutions.

But still, it's a bit of a clunky way to determine how well your graphics card will perform in newer games. Ballpark, sure, but nothing specific. For that, you should use more dedicated benchmarks like 3DMark.

While benchmarking some memory, Gearlog found that processor performance is a whopping 37% lower on a MacBook Pro running on AC alone. Cinebench R10's multiprocessor test got a battery-less Pro a score of only 3,504, while with the battery it scored 5,549. They contacted Apple to find out what's going on, and Apple admitted that the performance difference is intentional, explaining that it "prevents the computer from shutting down if it demands more power than the A/C adapter alone can provide." Sounds a little fishy to me, but it doesn't really matter: Apple took a lot of care with that battery, and if you know what's good for you, you'll leave it be. [Gearlog]

Multi-Touch Trackpad
After a month of getting used to the Multi-Touch touchpad on the MacBook Air, I have to say that the Pro's touchpad is not quite as good in comparison. Comparatively, the Pro's touchpad is slightly narrower in width and a whole half of an inch shorter in height. (It's identical to the touchpad on the last Gen MBP's pad.) My initial thoughts were that the smaller touchpad would make using Multi-Touch more difficult, but that wasn't exactly the case.

Initially, in iPhoto, Multi-Touch on the smaller pad was more difficult, but after a few minutes we realized we were trying to use fingers in the same fashion as we did on the Air, where we had more room to gesture. For example, on the Air we skipped through photos with our fingers vertically but because of the Pro's size it's not comfortable to do this. So we placed our three fingers horizontally and it worked perfectly.

We came to the same conclusion with the rotate function. Instead of trying to move our rotate finger from the top of the touchpad to the bottom, we realized that by simply doing the rotate movement with more of a flick, iPhoto and Preview correctly rotated our photo to the next layout.

For testing zoom, we did a side-by-side comparison with the Air and found that the Pro's smaller touchpad actually zoomed into the same position as it did using the Air.

Screen
One thing to note though is that the LED matte screen on the version we got was less bright than the glossy screen on the MacBook Air. This might be the matte vs. glossy difference, or it might be that the MacBook Air's screen is just brighter.

Keyboard
The updated keyboard now has the F-key functions, same as the MacBook Air, and we think the additional Dashboard and Expose buttons use the F-keys nicely. We might not actually use buttons for these features but we think it's cool that the buttons are now clearly labeled.

Benchmark
The Penryn MacBook Pro has already been benched and compared to the previous generation MBP, and its clear it's about the same performance, per GHz. With that in mind we tested the new Penryn MBP agaisnt a year old Merom MBP and found a slight increase in speed. Also not surprising.

In a video encoding test, the Penryn MBP exported a 2.5min HD trailer in 11 minutes, where as the older Merom MBP took 13 min. (The basic config on the older machine included a 2.33GHz processor and 2GB of RAM; the Penryn had a 2.6GHz processor and 4GB of RAM, so this test is just a rough guide.) As noted in the temperature section, the Penryn did use much more of its power to accomplish the encoding which produced more heat. If you would like to see the Xbench results and compare it to your own machine you can check them out here.

Temperature
While idling, the Penryn MBP's CPU was running at 127 F—slightly cooler than the Merom MBP which had 133 F. But as for the actual experience, the new Penryn MBP felt much cooler on your lap than the older Merom.

While performing a video encode in iMovie with the new Penryn MBP CPU was operating at a temperature of 170 F; actually warmer than the older Merom MBP at 165 F. The increase in operating temperature during a video encode is likely because the more efficient machine is still doing more work every second at its higher clock rate.

Battery
So why do Apple's battery ratings look the same or lower in comparison to the last generation's Macbook Pro ratings? Simple: They made the tests harder. Again, according to numbers provided by Apple, for this and the last generation's MacBook Pro's battery life, you get about half an hour more due to the Penryn redesign, and half an hour more from the LED backlights. As with the AirBook ratings, your mileage will definitely vary. Downwards. But relative to the older books, these are more miserly.

Conclusion
Overall this MacBook Pro update is nothing amazing. The Multi-Touch touchpad and the Penryn processor are nice upgrades, but not necessarily something that a previous generation MacBook Pro user would feel an urgency to upgrade to. This update is more about efficiency than power gains.