21.5-inch Core i3 iMacs Reviewed
Posted 10/19/2010 at 5:12pm
| by Susie Ochs
New chips, better graphics, same great style
With 21.5- and 27-inch LED-backlit screens under a glossy pane of edge-to-edge glass, the new iMacs don’t look different from the widescreen all-aluminum beauties from late 2009. But inside, it’s a whole different story--with Intel’s latest processors powering these new models, the 2010 iMacs should see impressive performance spikes. We set up the 3.06GHz Core i3 model ($1,199) and the 3.2GHz Core i3 model ($1,499) in the Mac|Life lab to test how an i3 really performs--and what those extra three bills for the 3.2GHz iMac really get you.

Instead of the Core 2 Duo processor in last year’s 21.5-inch iMac, Apple’s using the Core i3, specifically the 32-nanometer, 64-bit “Clarkdale” model with two multi-thread–capable cores. This chip adds support for Intel’s Hyper-Threading, which lets the two threads run on each core simultaneously so the OS can address four cores total. But the Clarkdale chip doesn’t support Turbo Boost, which shuts down unused cores to speed up the active ones.
The 2010 iMacs have better graphics, too. In 2009, the low-end 3.06GHz Core 2 Duo 21.5-inch iMac had an Nvidia GeForce 9400M graphics processor with 256MB of memory shared with the main RAM. Now you get a dedicated graphics processor, the ATI Radeon HD 4670 in the 3.06GHz Core i3, and the ATI Radeon HD 5670 in the 3.2GHz Core i3--each with 512MB of its own GDDR3 memory.
These upgrades deliver improved performance in games and other graphics-intensive tasks. We saw a huge jump in our Call of Duty 4 benchmark, with the new 3.06GHz Core i3 and 3.2GHz Core i3 iMacs hitting 75 and 77.4 frames per second, respectively. Last year’s 3.06GHz Core 2 Duo iMac only hit 36.1 frames per second in the same test.

Both the 21.5-inch iMacs come with 4GB total of speedy 1333MHz DDR3 RAM (as two 2GB modules; the other two RAM slots are empty). Dropping in another 4GB (two more 2GB >modules) for around $100 from an online vendor is a no-brainer, especially compared to Apple’s $200 build-to-order option for the same 8GB total. You can max out at 16GB.
The hard drive is the biggest difference between the two 21.5-inch Core i3 iMacs; the 3.06GHz model for $1,199 has a 500GB hard drive at 7200 rpm, while upgrading to the 3.2GHz model for $1,499 gets you 1TB of storage. Apple doesn’t let you order more storage in the $1,199 iMac and keep the slightly slower processor and graphics chip. But the $1,499 iMac has two more build-to-order options, including a 2TB drive for $150 and a 3.6GHz Core i5 processor for $200.
Other than those differences in storage, processor, and graphics, the two 21.5-inch iMacs have identical feature sets: four USB 2.0 ports, one FireWire 800, an SDXC card slot (which supports higher-capacity SDXC cards along with all the regular SD and SDHC cards you already have), and all the standard iMac bells and whistles you’re used to, detailed in our ratings boxes below. Apple includes the Wireless Keyboard, which we love, and the Magic Mouse, which we find a little less ergonomic than older mice, although still fun to use. But if you order from apple.com, you can opt for a wired Apple Keyboard and/or the Apple Mouse for no charge.
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As expected, the 3.2GHz model outperformed the 3.06GHz model in our testing, but not by much. Only two of our 10 tests showed a speed gain of more than 5 percent. And the Call of Duty 4 frame rate was only 3.2 percent better with the 3.2GHz model’s better graphics chip. So unless you need monster storage inside the iMac, you’ll be fine with the lower-priced 3.06GHz iMac, although both are excellent machines.
3.06GHz Core i3 iMac
COMPANY: Apple
CONTACT: www.apple.com
PRICE: $1,199
SPECS: 3.06GHz Intel Core i3, 4GB 1333MHz DDR3 SDRAM, 4MB shared L3 cache, 500GB 7200-rpm SATA hard drive, ATI Radeon HD 4670 graphics processor with 512MB GDDR3 memory, 1920x1080 glossy 21.5-inch LED-backlit TFT display with IPS technology, 4 USB 2.0 ports, FireWire 800 port, Mini DisplayPort, iSight, 802.11n AirPort Extreme, Gigabit Ethernet, SDXC card slot, optical digital/analog audio in/out, stereo speakers, Bluetooth 2.1+EDR, IR receiver, Apple Wireless Keyboard, Magic Mouse
Four RAM slots for 16GB maximum. SDXC slot supports cards larger than 32GB. Beautiful design and LED-backlit screen. Discrete graphics.
No build-to-order hard drive or processor upgrades from Apple. A non-glossy display option would be nice. No eSATA port.
3.2GHz Core i3 iMac
COMPANY: Apple
CONTACT: www.apple.com
PRICE: $1,499
SPECS: 3.2GHz Intel Core i3, 4GB 1333MHz DDR3 SDRAM, 4MB shared L3 cache, 1TB 7200-rpm SATA hard drive, ATI Radeon HD 5670 graphics processor with 512MB GDDR3 memory, 1920x1080 glossy 21.5-inch LED-backlit TFT display with IPS technology, 4 USB 2.0 ports, FireWire 800 port, Mini DisplayPort, iSight, 802.11n AirPort Extreme, Gigabit Ethernet, SDXC card slot, optical digital/analog audio in/out, stereo speakers, Bluetooth 2.1+EDR, IR receiver, Apple Wireless Keyboard, Magic Mouse
Four RAM slots for 16GB maximum. SDXC slot supports cards larger than 32GB. Beautiful design and LED-backlit screen. Discrete graphics. Build-to-order 2TB hard drive and 3.6GHz Core i5 available from Apple.
A non-glossy display option would be nice. No eSATA port.