When Apple launched the first iMac with Retina display last October, it stood alone in terms of competition from the usual Windows suspects, since no PC maker had anything close in design and performance. But it was also launched as a solitary model in the Apple catalogue, listed as just one standard configuration, although there was some limited scope to upgrade to better processor, graphics, storage and memory. Now we have an additional offthe- shelf Retina 5K iMac with £400 shaved off the £1,999 (now reduced to £1,849) price of the original. Your £1,599 can buy an iMac with the same ultra-high resolution screen and all the usual trimmings, with savings made this time in the main Intel chip, the storage and graphics.
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| Apple iMac with Retina 5K Display |
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| Retina iMac 5K |
Build and design
In every respect this is the same iMac with Retina 5K display, using the same chassis with the same formidable build quality, and the same line of ports and connectors along the back. There’s two Thunderbolt 2 ports for high-speed peripherals and external displays, four USB 3.0, gigabit ethernet, and slot for SD cards up to SDXC specification and a headphone jack. In place of the 3.5GHz Intel Core i5 quad-core processor is a slightly slower processor clocked at 3.3GHz. It’s from the same generation, a Core i5-4590 instead of Core i5-4690. Both chips have separate processor cores on the same die, and include Intel Turbo Boost 2.0 technology which here mildly overclocks up to 3.7GHz, where the faster processor can reach up to 3.9GHz.
These are regular four-core chips. In both cases, the processor is fixed at working on four threads, in contrast to the mobile-class processors found in most variants of Apple MacBooks, which include Hyper Threading Technology to give the effect of doubling the number of real cores. The memory quota and specification is the same as before, 8GB from two 4GB SO-DIMM modules, and you can easily upgrade this yourself from a removable hatch on the back In our tests of the main processor, we saw close to the same speed as from the 3.5GHz processor, with benchmark scores around 5- to 6 percent lower. From Geekbench 3, the new iMac with 5K Retina scored 3699 points with one core, and 11,792 while running four cores.
Those figures are around 5 percent lower than the 3877- and 12,418 points from the original iMac 5K. Cinebench 15 scored the 3.3GHz iMac with 134- and 515 points for its two modes, this time 6- and 5 percent behind the first model’s scores (143- and 544 points respectively). The earlier version of Cinebench 11.5 reported the same story, dropping 5- and 6 percent (1.64 down to 1.56 points, and 6.15 down to 5.79 points).
These are regular four-core chips. In both cases, the processor is fixed at working on four threads, in contrast to the mobile-class processors found in most variants of Apple MacBooks, which include Hyper Threading Technology to give the effect of doubling the number of real cores. The memory quota and specification is the same as before, 8GB from two 4GB SO-DIMM modules, and you can easily upgrade this yourself from a removable hatch on the back In our tests of the main processor, we saw close to the same speed as from the 3.5GHz processor, with benchmark scores around 5- to 6 percent lower. From Geekbench 3, the new iMac with 5K Retina scored 3699 points with one core, and 11,792 while running four cores.
Those figures are around 5 percent lower than the 3877- and 12,418 points from the original iMac 5K. Cinebench 15 scored the 3.3GHz iMac with 134- and 515 points for its two modes, this time 6- and 5 percent behind the first model’s scores (143- and 544 points respectively). The earlier version of Cinebench 11.5 reported the same story, dropping 5- and 6 percent (1.64 down to 1.56 points, and 6.15 down to 5.79 points).
Your £1,599 can buy an iMac with the same ultrahigh resolution screen and all the usual trimmings, with savings made this time in the main Intel chip.
At first glance, we have the same graphics processor driving all those 14.7 million pixels with 60 refreshes each second. But there’s something different in the designation, a certain X missing from the end of the device’s name. Where the first iMac 5K has an AMD Radeon R9 M290X, the second has an R9 M290. Technical differences between them are not revealed and we’ve asked Apple if it can explain how they are different. Until we hear more, and based on the tiny measured differences in performance between GPUs, we’d guess it could be something as minor as a difference in the core or memory clock speeds. Graphics processors can be ‘binned’ by selecting the best silicon from the fabrication process at time of manufacture, and setting these parts to run with the highest clock speeds. Those parts that don’t work with stability at the top speeds are set at slower clock speeds, and used in lesser graphics cards.
Graphics
As with Intel processor performance, the change of graphics processor see a small drop in the results we measured from the original 3.5GHz iMac 5K. Batman: Arkham City at 1920x1080 pixels and High detail still played perfectly at 84fps, where first model managed 89fps. When pushed to a Retina-mode resolution of 2560x1440 however, we saw a more significant drop in framerate, even if 66fps instead of 85fps is still perfectly usable to play the game without visible glitches.
Tomb Raider was strangely faster at full-HD resolution when played on the new 3.3GHz model, averaging 64fps against 59fps, for a nearly 7 percent improvement. But pushed to 2560x1440 size again it fell back by 10 percent, hitting 42fps instead of 46fps from the original 5K iMac. The Unigine Heaven synthetic game benchmark was similarly around 10 percent down, but still able to play the test at 27fps even at 2560x1440 and Medium detail. Cinebench’s OpenGL test pushes the graphics processor while rendering an animated car chase scene, and here the new iMac was just 1.4 percent behind the original in version 15 (90.4 versus 91.7fps); and again we saw an anomaly where the non-X-rated iMac turned in a higher score in the older 11.5 benchmark (56.3- beating 45.1fps, for a 20 percent better score in the cheaper Mac).
Tomb Raider was strangely faster at full-HD resolution when played on the new 3.3GHz model, averaging 64fps against 59fps, for a nearly 7 percent improvement. But pushed to 2560x1440 size again it fell back by 10 percent, hitting 42fps instead of 46fps from the original 5K iMac. The Unigine Heaven synthetic game benchmark was similarly around 10 percent down, but still able to play the test at 27fps even at 2560x1440 and Medium detail. Cinebench’s OpenGL test pushes the graphics processor while rendering an animated car chase scene, and here the new iMac was just 1.4 percent behind the original in version 15 (90.4 versus 91.7fps); and again we saw an anomaly where the non-X-rated iMac turned in a higher score in the older 11.5 benchmark (56.3- beating 45.1fps, for a 20 percent better score in the cheaper Mac).
Storage
As standard the original iMac with 5K Retina display comes with a 1TB Fusion Drive, a hybrid flash and disk system that works seamlessly to give you most of the benefits of a fast solid-state drive, and the bulk capacity of a traditional hard disk. The new entry-level version iMac is equipped with just a simple 1TB disk, which does make this model feel slower in general use. Start-up time is lengthened, even if this yardstick from the Windows PC world is almost insignificant here since Macs excel at sleep mode; and don’t demand restarting every Tuesday to apply weekly security patches from Microsoft. But there is some inevitable lag in the system interface, noticeable when applications take
a few more bounces in the Dock before they launch.
The Seagate hard disk inside this new iMac is fast though as disk technology can allow. With the drive nearly empty, it could reach sequential speeds up to around 210MB/s (with reads and writes effectively the same speed); the drag really starts to show when multiple demands are made upon the disk drive, and in small-file random read/write speeds.
Averaged with data from 4- to 1024kB, we saw speeds of around just 30MB/s. Compare this to the PCIe attached flash drives in other Macs, which would average around 300MB/s in the same latter test – a tenfold difference in speed, which would be even marked when the queue-depth (number of paralleled storage I/O operations) is increased. That’s not to say the diskonly iMac is too retarded to use comfortably. However if you’re used to using a MacBook Air, for instance, you may find a disk-based iMac even with its 3.3GHz quad-core processor may feel subjectively a little slower in daily use.
The Seagate hard disk inside this new iMac is fast though as disk technology can allow. With the drive nearly empty, it could reach sequential speeds up to around 210MB/s (with reads and writes effectively the same speed); the drag really starts to show when multiple demands are made upon the disk drive, and in small-file random read/write speeds.
Averaged with data from 4- to 1024kB, we saw speeds of around just 30MB/s. Compare this to the PCIe attached flash drives in other Macs, which would average around 300MB/s in the same latter test – a tenfold difference in speed, which would be even marked when the queue-depth (number of paralleled storage I/O operations) is increased. That’s not to say the diskonly iMac is too retarded to use comfortably. However if you’re used to using a MacBook Air, for instance, you may find a disk-based iMac even with its 3.3GHz quad-core processor may feel subjectively a little slower in daily use.
Verdict
For a pound under £2,000 the first iMac with 5K Retina display actually offers decent value,especially with nothing like it to compare, short of gaffer-taping a 4K UHD display onto a Windows tower PC. The new entry version undercuts it by a useful £400, bringing only around 5 percent slower application and 10 percent graphics performance. It does lose out with the slow disk-only storage though, so you might like to consider configuring it with a Fusion Drive or pure 256GB flash drive, either option adding £160 to the price.
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