New 21.5-inch Retina 4K models expected.
New Low-Cost iMac Nearly 50% Slower in Multi-Core, 10% Slower in Single-Core Benchmarks
As expected, the new machine posts relatively low 64-bit scores of 2820 in single-core mode and 5435 in multi-core mode. These scores are marginally better than the 2690/5254 scores posted by the current-generation MacBook Air running the same chip and roughly 10% slower than the 3168 single-core score from the previous low-end iMac model, which remains available.
But where this new low-end iMac falls far short of the previous low-end model is in multi-core performance, where the older model clocks in at 10253. This major difference is due primarily to the chip used in the new low-end model being a dual-core chip, while the older low-end chip is quad-core.
The new low-end iMac comes in $200 cheaper than the previous entry-level model, but for that savings users will sacrifice some CPU and graphics performance and will have a 500 GB hard drive rather than the 1 TB drive included in the more expensive low-end model.
Update 12:25 PM: Primate Labs' John Poole has shared a blog post putting the new low-end iMac's performance in perspective compared to other iMac models and highlighting a Tweet from Ars Technica's Andrew Cunningham noting that Apple's decision to use a chip from its MacBook Air line may have been made for graphics reasons.
I'd say Apple used an Ultrabook CPU in the new iMac to avoid shipping Intel's HD 4600 GPU in anything. No desktop CPUs include HD 5000.— Andrew Cunningham (@AndrewWrites) June 18, 2014