Apple today announced its new iMac 2021 based on custom M1 silicon, claiming significant performance gains over the older Intel Skylake-based designs. Let’s have a look at these claims and see how legit they likely are: In terms of CPU performance, the company is claiming a massive gain of up to 85% over the older Intel processors. While there may be certain single-threaded applications where Apple’s M1 SoC is indeed over 80% faster than its x86 predecessor, they are too few and far between, especially considering that most modern applications are multi-threaded. The M1 has only four high-performance “Firestorm” cores which limit its capabilities in multi-threaded workloads such as content creation, rendering, and simulation. In the majority of applications, the delta between the older and newer processors will be largely inconsequential while the Ryzen 9 alternatives from AMD based on the Zen 3 core architecture should be significantly superior.
In terms of GPU performance, Apple claims a 2x advantage over the preceding graphics processor. This again is a very ambiguous claim. The older iMac 2020 leveraged AMD’s RDNA based Radeon Pro 5300, 5500 XT, or the 5700 series GPUs with up to 16GB of memory. While Apple’s 7-8 core custom GPU offers a decent 2.6 TFLOPs of performance, it’s still a far cry from 9.75 TFLOPs delivered by the 5700 XT. Better driver and software support are another major positive for the older iMac over the custom Apple-designed GPU.
Then there’s AI or machine learning performance which the Cupertino-based company claims is a whopping 3x better with the M1 SoC. This is a grey area, as Machine Learning performance greatly varies from workload to workload. Considering that the Skylake core is more than 5 years old, this isn’t hard to believe, though in most cases, this advantage will be largely outweighed by pure multi-threaded compute performance.
Finally, there’s the matter of the price. The iMac 2021 is priced at $1,449 for the 8-core CPU, 7-core GPU paired with 8GB memory, and a 256GB SSD while the 8-core GPU variant costs $1,669. Increasing the drive storage to $1,899 pushes the overall cost to $1,899, making the already excessive price tag even more ridiculous.