Apple’s review units shipped with Intel’s Xeon W-2155 ten-core processor with a base speed of 3.3GHz, and a maximum turbo speed of 4.5GHz. According to this review by Jonathan Morrison, the processor scored a 5,450 in the Geekbench 4 single-core test, and a 37,434 in the multi-core test. That latter multi-core number puts the chip in the same ballpark as Intel’s Core i9-7900X 10-core chip for the mainstream desktop market, but it’s lower in single-core performance.
While the review basically focused on the perfect iMac Pro setup, another review posted by Vincent Laforet goes into deeper performance numbers. In Final Cut Pro X, he compared Apple’s review unit with his existing iMac 5K model with an Intel Core i7 CPU, 32GB of system memory, an AMD Radeon R9 4GB graphics card, and a 500GB Fusion drive. Also on the comparison list was a brand new 15-inch MacBook Pro with an Intel Core i7 processor, 16GB of system memory, a 1TB SSD, and a discrete AMD Radeon Pro 560 graphics chip.
He converted high-resolution media on all three devices, and saw the job completed in just under eight minutes on the new iMac Pro. The iMac 5K fell into second place with 15 minutes and 47 seconds followed by the 15-inch MacBook Pro in 19 minutes and 55 seconds. He saw a similar dominance in Black Magic Resolve converting 8K video to 4K footage.
Part of the huge performance boost stems from the speed of the iMac Pro’s SSD. According to Laforet, it managed a hefty write speed of 2,996MB per second, and a read speed of 2,450MB per second. Meanwhile, the MacBook Pro’s 1TB SSD saw a write speed of 1,743MB/s and a read speed of 1,400MB/s. The iMac 5K’s drive was significantly slower.
Craig A. Hunter’s review gets a bit more technical with workstation software, such as using NASA’s tools for computational fluid dynamics. Charts show a big performance gain over the MacBook Pro, the iMac 27, the Mac Pro, and more. The problem is, the comparisons are unfair because the closest models are generations behind. Hunter also notes that the iMac with an Intel Core i7 quad-core chip is slightly faster in single-core performance, but overall a 10-core chip provides more processing power.
Finally, Marques Brownlee points out that you’ll never be able to manually upgrade this $5,000-plus machine — there’s no visible way to get inside. He also provides Geekbench numbers similar to what we saw in the first review, but also lists an older iMac’s single-core benchmark that surpasses the new iMac Pro. Ultimately, the iMac Pro’s biggest weakness is apparently the inability to upgrade storage and memory for the big bucks you’re shoveling to Apple.