As soon as the iMac Retina was announced we immediately wanted to pit it against one of our custom Mac Pro 5,1 systems. So what did we do? We bought a 5K iMac, as well as a 4K monitor to go with the Mac Pro, and put them head to head. We ran a number of benchmark programs to test the CPU, GPU and storage configurations of the two systems.
Obviously, due to the Mac Pro’s advantage in internal expandability, we could technically create a £10,000 Mac Pro system. This would be unfair. So we limited our Mac Pro configuration (including the monitor) to the same price as the iMac (£2,879/€3,603). So without further ado, let’s get into the meat of this.
The Systems: Apple iMac Retina 5K
As the iMac’s price will dictate how we configure our Mac Pro, this seems the logical place to start. We chose the top spec processor and GPU, as well as maxed out RAM, however, we stuck with the standard fusion drive to keep costs under £3,000. Specifics below:
CPU: 4.0GHz Quad-core Intel Core i7, Turbo Boost up to 4.4GHz
GPU: AMD Radeon R9 M295X 4GB
Storage: 1TB Fusion Drive
Display: Built in 5K Monitor
Connectivity: 4x USB 3.0, 2x Thunderbolt, 1x Ethernet, 1x SD Card, 1x Headphone Jack
Total Cost: £2,879/€3,603
Things to note: The graphics card options in the iMac are all mobile cards, so typically wont perform as well as a full-size GPU. Fusion Drives consist of part HDD and part Flash Storage, in the case of the iMac’s drive there is 120GB Flash Storage.
The Systems: Create Pro Customised Mac Pro 5,1 & 4K Monitor
To go up against the iMac we chose a 12-core CPU to make use of current and future multi-threading support in modern applications. An AMD R9 280X as our graphics card to give Open CL grunt. Installed 32GB of RAM as in the iMac. In terms of storage, we went the same route as the iMac, combining Flash Storage and a traditional HDD.
CPU: 2.66GHz 12-core Intel Xeon X5650 (Our entry-level 12-core processor)
GPU: AMD Radeon R9 280X 3GB
Storage: 256GB PCI-E Flash Storage, 2TB HDD
Display: Dell UP2414Q 24″ 4K Display (£399/€499 brand new on eBay)
Connectivity: 2x USB 3.0 (on CalDigit PCI-E card), 2x eSATA 6GB/s (on CalDigit PCI-E card), 5x USB 2.0, 4x Firewire 800, Optical Audio In, Optical Audio Out, 2x Headphone Jack, 1x 1/8″ Audio Line In, 2x Ethernet, 2x Mini Display Port, 1x HDMI, 1x DVI
Total Cost: £2,826/€3,537
Things to note: RAM clock speed is slightly slower than the iMac’s RAM (1333 vs 1600).
Now that both systems have been introduced, let’s look at part specific performance to see which system is best.
CPU Performance Test: Geekbench
To test CPU performance we kept it classic with Geekbench, no fuss, highest score wins. The Mac Pro has the advantage as it has 3 times more cores than the iMac, but the iMac’s single core clock speed is impressive so this should be interesting. Overall performance will be the main criteria here, but single core scores shouldn’t be completely overlooked.
Winner: Custom Mac Pro (60% higher score)
Notes: In this test the Mac Pro was the clear winner with a score of 25566 against the iMac’s score of 15955. The 12 core setup gives a silly amount of power that the iMac just can’t match. As we said, however, the iMac does have stronger single core performance, which is also important within some applications. As we move into the future though, apps are going to keep improving their already good multi threading support, again giving weight to the classic Mac Pro’s argument.
GPU Performance Test: LuxMark Sala
Next up, GPU performance with LuxMark. As both cards tout Open CL support, this was the obvious choice. We chose the Sala test to be the main criteria as this is generally the most popular test within the Mac community. We tested GPU alone without the help of CPU. We already had information on CPU processing power from the previous test. Results come as a single score so the winner is easy to decide.
Winner: Custom Mac Pro (45% higher score)
Notes: The Mac Pro’s R9 280X showed that even modern mobile cards aren’t much of a match for their desktop relatives. Not to say the iMac’s score was bad, but the R9 280X came out as a much more competent GPU with a score 45% higher than that of the iMac’s card. Just for information’s sake we also ran the Room and BallHDR tests and the results were similar. The Mac Pro scored 46% higher than the iMac in the BallHDR test and 32% higher in the Room test with scores of 19286 and 1232 respectively.
Storage Performance Test: AJA System Test
Storage is becoming an increasingly heated battleground these days with HDD’s no longer being the only option available. SSDs and Flash Storage are now providing serious performance boosts to systems when installed. To test which is best we decided to look at read/write speeds, we feel both are important so the winner will be the system with the highest combined score. Read speeds are important for opening large files as well as working with data that is stored on that specific drive. Write speeds are important for exporting files to specific drives. All scores are in MB/s.
Notes: Another landslide victory for the Mac Pro here, both read and write speeds are significantly faster than those of the iMac’s Fusion Drive. Obviously the read/write speeds of the HDD storage portions will be significantly lower, but this should be used for data storage rather than active work. Also of note, the Mac Pro actually has a significantly larger Flash Storage capacity, 256GB against the iMac’s 120GB as well as a 2TB HDD against the iMac’s 1TB.
Which Display is Better?
After spending time with both of these displays we can safely say that they are both incredible. They represent a huge step up from current Apple displays in every single way. Colours are the richest we’ve seen and the OS X interface has never looked sharper. If you’re editing 4K video they are both solid solutions. The Dell monitor we chose (UP1414Q) is 24″ in size, clean and simple in design and has a native resolution of 3840x2160px. The monitor also has an ultrawide viewing angle of 178 degrees, Adobe RGB 99% colour rating, a 100% sRGB colour rating and is fully Retina compatible. The iMac display is larger at 27″ and has a higher native resolution of 5120x2880px. Other specs aren’t listed on the Apple site, but it’s safe to say the display is simply awesome.
Winner: iMac 5K
Notes: Although both are great solutions for pixel hungry individuals, the iMac is definitely the better of the pair. The higher native resolution gives OS X an extra crisp over the Dell monitor. The Dell isn’t bad, it’s also an incredible piece of kit, we just had to pick a winner and this time it’s the iMac.
Who has the Best Connections?
Without listing the huge amount of connections on each device (they are listed above in the system overviews), here’s a quick summary. The iMac has limited connections out of the box, but it does have two thunderbolt ports. The Mac Pro has a wider variety of connections and more of each, but lacks thunderbolt. This really comes down to personal preference, is thunderbolt important to you? Or are you more interested in having a huge variety of in the box inputs and outputs?
Winner: Draw (comes down to preference)
Notes: Not much to say here, how much do you need Thunderbolt?
Who Wins? Custom Mac Pro or iMac 5K?
The Mac Pro walked all over the iMac in terms of computing performance. The CPU scored 60% higher than the iMac’s, the GPU scored 45% higher, disk write speeds were 157% higher and read speeds 63% higher. The performance gap observed is more than significant. The Mac Pro showed that towers are still in a completely different category to the all-in-one desktop. The iMac wasn’t completely walked-over, however, the display did top that of the Dell UP2414Q that we bundled with the Mac Pro and connectivity was a tie coming down to personal preference.
Winner: Custom Mac Pro
Notes: If we give each category an equal rating the Mac Pro 5,1 wins with 3.5 points vs 1.5. The tower is certainly the better choice for professionals who value performance over form. We were thoroughly impressed by the iMac, however, especially it’s single core performance and stunning display. We can see the iMac’s place if you’re looking for something to sit at home with enough power to complete most tasks. But if you’re a professional looking for a serious system that will handle anything you throw at it, the Mac Pro is still the best choice.
Bonus: What if we put two R9 280Xs in the Mac Pro?
As the system was on the workbench and we had a few more R9 280Xs in the office, we thought, why not? The 280X is a powerful Open CL GPU and with some in-house modding we have figured out how to internally-power two in one Mac Pro 5,1 system. We put both GPUs in the tower’s PCI-E x16 slots and moved the Flash Storage to the x4 slot (with no performance drop, we tested it). The system not only looked awesome, it was awesome. We ran the same LuxMark test that we performed with the single card and iMac 5K GPU. Dual R9 280Xs scored a huge 4838. This score is significantly higher than the top spec GPU configuration in the Mac Pro 6,1 which scored only 3527 on barefeats.
Should you wish to improve performance through storage rather than adding additional GPUs, we can RAID together two 512GB PCI-E Flash Drives to achieve incredible read speeds of 2,200MB/s and write speeds of 1,950MB/s. More details on our flash storage options in a previous blog post here.
Some people like to see evidence, so here are all of our screengrabs from the tests we performed.