How fast are the "Late 2012" Aluminum iMac models compared to one another? How much faster are the "Late 2012" models than the "Mid-2011" models replaced?

Please note that the "Mid-2011" and "Late 2012" iMac models have been discontinued. However, this Q&A still can be quite helpful to anyone buying or selling one of these systems on the used market.

In the official company press release for the "Late 2012" Aluminum iMac models -- the iMac "Core i5" 2.7 21.5-Inch, "Core i5" 2.9 21.5-Inch, "Core i7" 3.1 21.5-Inch, "Core i5" 2.9 27-Inch, "Core i5" 3.2 27-Inch, and "Core i7" 3.4 27-Inch -- Apple notes that the systems offer "faster performance" but places more emphasis on graphics than overall speed, and more specifically proclaims that the systems "deliver up to 60 percent faster performance for advanced gaming and graphics intensive apps."

Without official numbers for overall performance, unofficial details can be particularly worthwhile. Objective third-party graphics performance details can be helpful, too.

Photo Credit: Apple, Inc. (21.5" & 27" Tapered Edge iMac, Left & Right, Respectively)

General Performance Overview

For a solid overview of the performance difference between the "Late 2012" Aluminum iMac models and earlier iMac systems, EveryMac.com's own Ultimate Mac Comparison makes it quick to compare side-by-side 32-bit-and 64-bit Geekbench benchmark averages with all other G3 and later Macs for thousands of possible performance comparisons.

The Geekbench 2 benchmark shows that the high-end stock 21.5-Inch model -- the iMac "Core i5" 2.9 21.5-Inch -- is roughly 12% faster than the entry-level model. The configure-to-order iMac "Core i7" 3.1 21.5-Inch is 51% faster than the entry-level model and 35% faster than the stock high-end model.

Geekbench also shows that the entry-level 27-Inch model -- the iMac "Core i5" 2.9 27-Inch -- is roughly the same speed as the high-end stock 21.5-Inch model -- the iMac "Core i5" 2.9 21.5-Inch (but has RAM that is much easier to upgrade). The high-end stock 27-Inch model -- the iMac "Core i5" 3.2 27-Inch -- is a mere 2% faster than the entry-level 27-Inch system, but the configure-to-order iMac "Core i7" 3.4 27-Inch is a much more significant 39% faster than the entry-level model and 37% faster than the stock high-end model.

Compared to the "Mid-2011" line, Geekbench shows that the "Late 2012" systems are between 10% and 21% faster than the model each replaced:

Mid-2011 iMac	Late 2012 iMac	Percent Faster
"Core i5" 2.5 21.5"	"Core i5" 2.7 21.5"	13%
"Core i5" 2.7 21.5"	"Core i5" 2.9 21.5"	17%
"Core i7" 2.8 21.5"	"Core i7" 3.1 21.5"	21%
"Core i5" 2.7 27"	"Core i5" 2.9 27"	18%
"Core i5" 3.1 27"	"Core i5" 3.2 27"	13%
"Core i7" 3.4 27"	"Core i7" 3.4 27"	10%

Other Benchmarks & Real-World Test Results

Geekbench provides a convenient overview of overall performance, but other benchmarks and real-world tests still can be helpful, particularly for graphics performance and disk-related tasks.

In a pair of reviews for the 21.5-Inch and 27-Inch models, the industry standard Macworld put the line through its paces with the publication's own Speedmark 8 benchmark. For the 21.5-Inch models, the results were as expected:

The new high-end 21.5-inch 2.9 GHz iMac was 12 percent faster than the previous high-end 21.5-inch iMac with a Sandy Bridge 2.7 GHz Core i5 quad-core processor in our MathematicaMark tests and 17 percent faster in the Cinebench CPU test. The new entry-level 21.5-inch 2.7 GHz iMac was 11 percent faster than the previous entry level 21.5-inch iMac with a Sandy Bridge 2.5 GHz in both MathematicaMark and Cinebench CPU tests.

For the 27-Inch models, however, the entry-level system arrived with a faster hard drive thanks to twice the amount of cache, and as a result, the entry-level model was actually faster than the high-end stock model in "nine out of fifteen tests." Overall, however:

In better news for the [US]$1999 iMac, it was faster than the [US]$1799 iMac in both the Cinebench CPU test (7 percent faster) and MathematicaMark (5 percent faster). The [US]$1999 iMac was also faster than its predecessor, a 3.1 GHz Sandy Bridge quad-core Core i5 system. This year's model was 19 percent faster overall than the 2011 high-end iMac, 14 percent faster in the Cinebench CPU test, and 16 percent faster in our Handbrake test. . . The new [US]$1799 iMac 2012 was 28 percent faster overall than its predecessor, a 2.7 GHz Sandy Bridge quad-core Core i5 system. The new [US]$1799 iMac's zippy hard drive, larger amount RAM, and faster CPU all contribute to its increased speed.

The excellent ArsTechnica also reviewed the 21.5-Inch and 27-Inch models separately. For graphics, specifically, on the entry-level iMac "Core i5" 2.7 21.5-Inch, the site noted that the model it replaced sometimes was faster in real-world use:

In both Portal 2 and Arkham City, the GeForce GT 640M in the 2012 iMac pulls ahead very slightly and the 3DMark benchmark shows it slightly ahead as well. It does fall behind the 2011 iMac by a significant margin in Minecraft -- it's still playable, but you may still run into titles that run better on last year's entry-level iMac than on this one. The higher-end 21.5-inch and 27-inch iMacs all use much more powerful GPUs [though].

For the top-of-the-line CTO model -- the iMac "Core i7" 3.4 27-Inch configured with the NVIDIA GeForce GTX 680MX and 2 GB of dedicated GDDR5 -- ArsTechnica reported results that are decidedly more straightforward with massive percentage gains for the "Late 2012" system compared to its predecessor in 3DMark, Cinebench, and other benchmarks across the board.

If Geekbench for overall performance and the above reviews for graphics and storage performance aren't enough for you, the details oriented BareFeats has a number of performance evaluations for both the 21.5-Inch and 27-Inch models including benchmarks, gaming, pro apps, graphics, and more.

Performance Test Results Video

For those who prefer video to text, TLDToday also detailed the graphics performance of the "Late 2012" iMac models.

Specifically, the reviewer stresses the entry-level iMac "Core i5" 2.7 21.5-Inch model with the Battlefield 3 game via Boot Camp and the high-end iMac "Core i7" 3.4 27-Inch custom configured with the NVIDIA GeForce GTX 680MX and 2 GB of dedicated GDDR5 memory with a series of tests in After Effects CS6.

21.5-Inch Graphics Performance (Battlefield 3)

27-Inch Graphics Performance (After Effects CS6)

As you can clearly see from watching the above videos, the graphics performance of the 21.5-Inch model is usable, but not particularly spectacular. The CTO 27-Inch model, on the other hand, offers impressive graphics performance.

Performance Summary

Ultimately, the "Late 2012" iMac models are notably faster overall compared to the "Mid-2011" iMac models replaced.

However, as the above benchmarks and tests demonstrate, on some graphics tasks, the entry-level 21.5-Inch "Late 2012" iMac model only is marginally faster, or even slower, than its predecessor. Likewise, the 27-Inch models are faster than the models each replaced overall, but some systems could be faster still if it were not for a relatively slow default hard drive.

For those interested primarily in performance, the configure-to-order iMac "Core i7" 3.4 27-Inch model, preferably equipped with the faster NVIDIA GeForce GTX 680MX graphics card, in addition to the "Core i7" processor upgrade, is the top option among the "Late 2012" iMac systems.

For one looking for the best price-to-performance ratio among the "Late 2012" systems -- and who are less concerned about graphics performance -- the entry-level 27-Inch model -- the iMac "Core i5" 2.9 27-Inch -- is ideal as it originally had a 10% lower price tag than the stock high-end 27-Inch model -- the iMac "Core i5" 3.2 27-Inch -- but only is 3% or so slower overall. Of course, on the used market, prices are lower still.

Used iMac Purchase Options

There are many places to purchase a used "Late 2012" iMac. However, buying from a quality merchant with an extensive track record in the Mac market will provide the best experience and save you money and time, too.

In the US, site sponsor Adorama sells new iMac models with free shipping. Other World Computing and JemJem sell used and refurb iMac models at bargain prices with free shipping, as well. Finally, if you need to sell an iMac, A+ BBB-rated Cash for Your Mac will buy your older iMac with an instant quote and prompt payment.

In the UK, site sponsor Hoxton Macs sells used iMac models with a one-year warranty and free next day delivery throughout the UK. Delivery across Europe also is available starting at just £9.99 for two-day delivery to France and Germany.

In Australia, site sponsor Mac City likewise has a variety of used iMac models sold at low prices and available with a free warranty and fast shipping across Australia.