The new 27in 5K iMacs jump from Haswell to
Skylake - which is two CPU generations, they also move up one GPU
generation, and the storage bandwidth is twice as much. In addition, the
display quality is better than ever and you can buy 64GB of third-party
RAM as a user upgrade. All this adds up to a pretty impressive update.
Our main criticism is that the Fusion Drive isn’t standard across the
range, and, even worse, the SSD part is now much smaller. However, the
new 27-inch iMac line-up is great value for money, if you were to
purchase a 5K display of this quality it would cost a lot more than the
price of the 5K iMac, and it wouldn’t come with a fast, capable, fully
functioning computer
There are three standard 27in models. These are spec-ed and priced as follows:
iMac, 27in, quad-core 3.2GHz, 1TB hard drive, AMD Radeon R9 M380, £1,449
iMac, 27in, quad-core 3.2GHz, 1TB fusion drive, AMD Radeon R9 M390, £1,599
iMac, 27in, quad-core 3.3GHz, 2TB fusion drive, AMD Radeon R9 M395, £1,849
If you were to fully spec out the ultimate top of the range
build-to-order (BTO) model you could get: 4GHz quad-core i7, 32GB of
RAM, a 1TB SSD, and faster AMD Radeon R9 M395X graphics – it would cost
you £3,289. £1,440 more than the standard top of the range model, and
just £10 less than the top of the range standard Mac Pro, which costs
£3,299.
There’s also a new range of 21.5in iMacs, including one with a 4K Retina display, which we look at here:
New 21.5-inch iMac with Retina 4K display. Read more about the new range of iMacs here:
Apple launches 21.5in Retina iMac, updates 27in iMacs with Skylake.
2015 27in iMac with Retina display: Processors and speed tests
All the new 27in models include Skylake quad-core i5 processors from
Intel running at 3.2GHz or 3.3GHz. Skylake is the name of Intel’s sixth
generation processors. Intel claims that these processors offer better
CPU and GPU performance while reducing power consumption. They use the
14nm manufacturing process (which is the same as Broadwell).
Skylake launched very soon after Broadwell did – mostly because
Broadwell encountered many delays. As a result many manufacturers have
side stepped Broadwell all together. Note: The 21in iMac models are
using the older Intel Broadwell chips because Apple relies on the on
system graphics chip for those models and as yet that isn’t available
for Skylake.
On the entry-level model the Skylake processor is a marked leap up
from the 3.2GHz processor in the original entry-level model. However,
the mid-range model sports the same 3.2GHz processor (the difference
between these two models is in terms of graphics and storage, more on
that below).
This might appear to indicate a decline on the speed of the previous
mid-range model, which offered 3.3GHz for the same price. However, it
should be noted that these are next generation processors so
theoretically the 3.2GHz Skylake chip of this generation could be faster
than the 3.3GHz chip from earlier in 2015.
Similarly, at the top of the late 2015 iMac range is a 3.3GHz processor, again a slower clock speed than the older model.
Testing suggests that if you happen to have a Mac with a a similarly
clocked Haswell chip, the gains are quite small, although when it comes
to the entry-level model, the £1,449 27in iMac with its 3.2GHz Intel
Core i5-6500 seems to clock in at about 10% faster than the 3.5GHz Core
i5 Broadwell chip in the original 5K iMac model from 2013.
There's also a BTO model that offers a quad-core Skylake i7-6700K,
running at 4.0GHz (or up to 4.2GHz Turbo). This processor in the BTO
iMac is also faster than the processor in the entry-level quad-core Mac
Pro (which costs £2,499). That doesn’t mean the 5K iMac is necessarily a
better choice than the Mac Pro, which also offers far faster 6, 8, or
12 CPU cores, which might be what you need. The 8- and 12-core versions
of the Mac Pro are in a different league to the iMac, imagine
what’s possible if Apple finally upgrades the two year old Mac Pro.
We haven’t run Geekbench on the new 27in 5K iMacs yet, but we have
these results from the models we tested this summer that we will add
here now in preparation for the new set of results.
The results were as follows:
Geekbench 3 single-core 64 bit
3.3GHz 27in 5K iMac (mid 2015) : 3,691
Geekbench 3 multi-core 64 bit
3.3GHz 27in 5K iMac (mid 2015) : 11,769
2015 27in iMac with Retina display: Graphics and speed tests
The new 27in iMacs features AMD Radeon R9 GPUs, with each model getting a more advanced graphic chip.
The entry-level 3.2GHz model features the AMD Radeon R9 M380 with 2GB video memory
The mid-range 3.2GHz model features the AMD Radeon R9 M380 with 2GB video memory
The top-of-the-range 3.3GHz model features the AMD Radeon R9 M395 with 2GB video memory
with 2GB video memory
BTO iMac offers a AMD Radeon R9 M395X with 4GB video memory
One of the key differences between the 21.5in and the 27in iMac is
that the larger model offers a dedicated GPU while the 21.5in models
offer a graphics chip integrated on the processor itself. The graphics
processors in the newest 27in iMac are all from AMD, and you will find
the Radeon R9 M380, R9 M390 and R9 M395X depending on which model you
buy.
It appears that despite the upgrade, these AMD GPUs aren’t a lot
better than the graphics chips in the previous models. However, at the
top end the new GPU is said to be better than the GPU in the previous 27
iMac which gamers complained would overheat and lower its clock speed.
As a result, the AMD Radeon R9 M395 GPU in the £1,849 5K iMac is able to
handle some mainstream games at decent settings, but if you are a keen
gamer, you will be disappointed, it won’t be capable of the same
performance as a gaming PC.
Using the Unigine’s Heaven benchmark we can get some idea of the 2015
iMacs’s gaming capabilities. Having set the resolution to 2,560 x 1,440
with medium detail we found that the R9 M390 (the £1,599 model) was
able to manage 26fps. So if you do want to use your iMac for gaming, its
best to opt for about 2,560 x 1,440 resolution for the least stuttery
experience. It seems that the 14.7 million pixels the iMac is capable of
are just too many for it to cope with when dealing with high graphics
gaming. If you need to max out multiple CPU cores and GPUs then the Mac
Pro is the machine for you.
The 21in models have the graphics chips integrated on the CPU, so if
you need the extra power of a discrete graphics processor you will be
better off opting for the 27in models. The new 21.5in iMacs can’t even
compete with the older 27in iMacs in terms of graphics. Which isn’t a
big surprise given the fact that the GPU is integrated on the processor
in the 21in models and separate in the 27in iMacs. Our colleagues at
Macworld US ran Cinebench tests and found that while the new 3.1GHz
21.5in iMac performed better than it’s predecessor, despite the fact
that it is driving four times more pixels, it was left behind by the 5K
3.3GHz iMac that launched in mid 2015.
2015 27in iMac with Retina display: Display
Unlike the 21in iMac range, where only the top of the range model
gains a 4K Retina display, Apple’s range of 27in iMacs are all now
furnished with a 5K Retina display. Prior to the October range update
only two of the 27in iMacs had the higher resolution display.
All three Macs offer a resolution of 5120 x 2880 - that’s 67 percent more pixels than a
4K display.
The new 27in iMac has a display that might sound the same on paper to
the 5K display in the preceding models, but it actually has a wider
colour gamut. The newer models have a wider P3 colour gamut and will
deliver 25 percent more colours than the previous one, according to
Apple. It is capable of displaying 130 percent of the sRGB gamut,
according to tests.
That original 5K display was found to have a full 100 percent
coverage of the basic sRGB colour gamut. In terms of the Adobe RGB
colour space, that iMac recorded 78 percent cover, althoguh others have
seen it achieve 86.1%. These new 27in Retina models are also able to
show more than 99 percent of the DCI-P3 colour space. DCI-P3 is the
colour space for digital movie projection. It encompasses the entire
sRGB colour space and in addition can display even more shades of red
and green (the knock on effect of which is that colours like yellow,
orange, and magenta also improved). Only blues and cyan are lacking - or
rather pretty much the same as they are in sRGB.
In order to widen
the colour gamut Apple switched away from using white LEDs for
backlighting (actually a white LED is a combination of a blue LED with
yellow phosphor). Instead Apple is now using red-green phosphor LEDs.
Moving on to resolution, that hasn’t changed, the 27in iMac still
offers 5,120 x 2,880 resolution which adds up to 14.7 million pixels.
When we tested the 5K Retina display on the 2014 5K Retina iMac we saw
it turn in some of the best numbers our colorimeter had ever measured.
On this model, the contrast ratio is 1,166:1, with regards to the
previous generation, at its full output we saw the highest contrast
ratio we’ve measured in the standard chequerboard test, returning a
figure of 1160:1. In evaluation the new Delta E rating was 0.72, while
previously in our colour accuracy test of the 2014 top of the range
Retina model, returned an average of 1.66 Delta E (A Delta E of 1.0 is
considered the smallest color difference the human eye can see).
When we tested the original 27in Retina iMac we also found full
brightness to be 445 cd/m^2. In some tests the new 27in iMac managed 382
cd/m^2 according to a light meter, which is an impressive number
although not quite as bright as the older model, although other tests
have found the new monitor managed 466cd/m² (perhaps there is a
difference in screen supplier).
One criticism of the new 27in iMac displays is that the iMac’s
backlighting doesn't appear to be quite as rigorous as it is on some pro
monitors, in testing, it was found to be between 10% and 16% dimmer in
the bottom-left corner, obviously designers want a display that is
consistent across the whole panel. (The 21in model didn't suffer this
fault, so again, it could be a faulty batch).
The other along standing criticism is that there’s no height
adjustability – you can only tilt the iMac back and forth, the only way
to raise the monitor is to sit it on one of those hard back books you
have lying around.
The other criticism is that Apple you can’t use
Target Display mode on the 27-inch iMac so you can’t plug it in to
another computer (not even a Mac Pro) and use it as a 5K monitor. We
hope that Thunderbolt 3 makes it into the next generation as this could
allow this.
With all that said, there are not many 5K monitors that you can buy
right now, and certainly not any that cost around £1,500 and come with
an integrated computer.
There is more to the
Retina display
than being able to see subtle details thanks to the extra pixels. The
high pixel count means you can set the display to an alternate
resolutions without sacrificing image quality. For example, if you want
everything to be a little bit bigger you can set the 5K iMac to emulate a
smaller monitor (via System Preferences > Display).
Read our Mac buying guide
2015 27in iMac with Retina display: Ports
The ports haven’t changed on the mid-range and top-of-the-range 27in
iMac (although the entry-level previouls non-Retina 27in iMac and the
21in iMac range was so out of date that Apple had to sort out some of
the embarrassing ommissions in that model, such as Thunderbolt 2 - those
models only offered Thunderbolt 1). Speaking of which, we’d like to see
Thunderbolt 3 in the iMac, as we said in the display section,
Thunderbolt 3 would allow users to plug the iMac into another computer
and use that 5K display, it would also bring USB Type-C (which is
incorporated in Thunderbolt 3) and obviously it would speed up any
accessories plugged in to those already pretty speedy ports.
Right now the 27in iMac will give you two Thunderbolt 2 ports, four
USB 3.0 ports, an SDXC card slot, a headphone jack and an Ethernet port
You’ll also get some not-so-bad integrated speakers, along with the
new Magic Keyboard and Magic Mouse - unless you’d prefer to opt for the
Magic Trackpad. The new 27in iMacs ship as standard with the new
Magic Mouse 2 (or you can switch it to the Wired Apple Mouse if you prefer).
The new
Magic Trackpad 2
costs an additional £44 as a build to order option, or you can get both
the Magic Mouse 2 and the Magic Trackpad 2 for £109. In this case you
are essentially paying for the Magic Trackpad 2; if you were to buy them
separately the new Magic Mouse 2 costs £65 and the Magic Trackpad 2
costs £109 - the mouse is bundled with the iMac so you don’t have to pay
for it in this instance.
You can
purchase the Magic Mouse 2 on the Apple Store here, and the
Trackpad 2 is available from the Apple Store here. There's also a new Magic Keyboard (Apple's getting a bit carried away with the Magic). The
Magic Keyboard is available to buy here.
Find out what port does what here:
Guide to Mac and iPhone ports: what is USB Type-C, Thunderbolt & Lightning
2015 27in iMac with Retina display: Storage
The storage is one area where the iMac is let down - particularly at
the 21.5in level, but also on the entry level 27in Retina model. Apple
still uses an old fashioned hard drive (HDD) in these models as
standard. The 21.5in models are even worse off, those hard drives are
even slower than the one the 27in model - 5400rpm compared to 7200rpm.
The other two 27in Retina iMacs ship with Fusion Drives as standard
which is a blessing at least because it offers the best of both worlds, a
fast flash (SSD) drive and a large HDD in one. Opting for a hard drive
if you are used to flash storage will make the Mac feel slow.
The Fusion Drive combines a large hard drive for space, and a smaller
SSD for quick access of frequently used files and start up information.
The way the Fusion Drive works is it will store the important OS X
files and applications that you use the most frequently, so that these
load up quickly, and as a result you can get near instantaneous wake
from sleep. There also used to be plenty of space to store frequently
accessed files on the SSD but the bad news for this generation is that
Apple has slimmed the SSD part of the 1TB Fusion Drive down to a measly
24GB of storage from 128GB. As a result it’s cheaper as a build to order
option (£80), but frankly it limits the storage so you won’t be able to
store as many frequently used large apps and files on the SSD, which
could spell a slower experience day to day. The 2TB (an extra £160, or
standard on the top-of-the-range model) and 3TB (an extra £240) versions
of the Fusion Drive still offer the 128GB flash drive.
Now that Apple has reduced the spec of the Fusion Drive and reduced
the build-to-order price, we think all iMacs should ship with a Fusion
Drive, surely Apple can swallow the price of what we think is an
essential £80 update. For now we strongly recommend that you upgrade to
Fusion, or if you don't need the space, grab a SSD at the build to order
stage when you purchase the machine as it will make a significant
difference the the speed at which it runs.
Speaking of SSDs, back in 2013 Apple switched from the SATA interface
to PCI Express which improved performance no end (PC manufacturers
still haven’t done this). Going one better, this year Apple has further
improved performance by attributing even more PCI Express bandwidth to
its SSDs. The SSD and Fusion Drives in the new iMacs now get four PCI
Express 2.0 lanes which is double that of the 2013 and 2014 iMacs. The
new drives also use the NVMe protocol. Because the flash storage can
take advantage of upgraded storage controllers and four lanes of PCI,
Apple says this allows them to achieve flash-storage transfer speeds up
to 2.5 times those of previous models.
If you don’t need the space but would love things to be as fast as
possible, and you will be frequently accessing large media files, the
Flash Storage options might be preferable. For the £1,449 iMac, there’s a
256GB Flash upgrade for £80 or 512GB for £320. These prices are lower
for the 27in models than the 21in models). On the £1,599 model 256GB
Flash is £80, 512GB is £320, and 1TB is a wallet-wrecking £720.
As you’d expect, with a Fusion Drive you can access files pretty
quickly, for example, in tests we saw 687MB/sec for reading files, and
170MB/sec for writing them to the disk. This isn’t as fast as pure flash
storage though.
It’s our opinion that no iMacs should be using hard
drives in this day and age. If you are desperate for the extra capacity
of a HDD, get a separate hard drive, or even better a NAS drive.
If you are thinking of getting the entry-level 27 Retina iMac you
might think that £80 is a small price to pay for the benefit of the
Fusion Drive, but it will bring the price of the iMac to £1,529, so you
might as well skip this model and buy the £1,599 iMac which comes with
the Fusion Drive as standard. You’ll also get the slightly better
graphics card. It depends if you think that the £70 difference is enough
to warrant the improved graphics. Our advice if you are buying the
entry-level model, avoid the hard drive, if you really need all that
storage get an external drive and use that.
Find out more about which storage to add to your Mac here:
How to add more storage to your Mac | Hard drives, flash storage, NAS - find out which storage option is best for you and
SSD vs hard drives: which is the best storage to have in a Mac
2015 27in iMac with Retina display: RAM
Macs are notoriously difficult to upgrade, in fact the 21.5in iMac is
impossible to upgrade yourself so we recommend making sure you get all
the extras you might need at point of purchase. However, there is a
little more flexibility with the 27in model. While the new 27in iMacs
comes with 8GB RAM all models are configurable to 32GB at point of sale.
You can opt for up to 32GB of RAM at point of purchase, but you can
also access the RAM slots later on and there is an option to buy 64GB of
RAM from a third party and add it yourself at a later date. If you are
unlikely to tinker with your iMac or needs that much RAM, we recommend
that you purchase the 16GB RAM option at the build to order stage - it’s
an extra £160 but we think it will be worth it in the long run.
Incidentally, if you purchase 32GB RAM as an upgrade from Apple it
will cost an extra £480. You will be able to purchase 64GB RAM from OWC
for $1195 (approx £772, UK price TBC). German reseller Memphis has been
in touch to confirm that they will be selling 64GB RAM for the new iMac
on Amazon UK - you can
buy the 64GB RAM-Kit here for £575. We also expect that
Crucial will be offering 64GB RAM as well.
2015 27in iMac with Retina display: Price
in mid 2015 Apple reduced the price of the top of the range iMac from
£1,999 to £1849. If you were hoping the company might have reduced
prices further you’re out of luck, but at least the new entry-level 27in
iMac retails at £1,449 (the same price as it’s non-Retina predecessor),
meaning you can now get a 5K Retina iMac for less than £1,500. Mind
you, can now purchase a Retina iMac for £1,199 albeit with a 21in
display. But it does mean the point of entry for a Retina display iMac
is lower than ever.
The full range of 27in iMacs are priced as follows:
iMac, 27in, 3.2GHz, 1TB hard drive, AMD Radeon R9 M380, £1,449
iMac, 27in, 3.2GHz, 1TB fusion drive, AMD Radeon R9 M390, £1,599
iMac, 27in, 3.3GHz, 2TB fusion drive, AMD Radeon R9 M395, £1,849
You can
buy the new 27in Retina iMac from Apple’s online store here.
You can
buy the new 21in Retina iMac from Apple's online store here.
As we discuss in our
review of the 21in Retina iMac, which even at £1,199 is not the cheapest Mac with a Retina display you can buy, you can get a
13-inch Retina MacBook Pro
for £999 – that’s a lot less than the entry price for the 27in Retina
iMac, but that MacBook has a far smaller display and a slower processor,
so if you will benefit from the larger display you may feel that the
extra £450 is worth it – after all, were you to fork out for a 5K
display to use with your laptop you’d probably be looking at spending a
lot more. Read more
Retina MacBook Pro reviews here.
Interested in the earlier iMac models? There are likely to be some
discounts on earlier models available from Apple’s refurbished store
(although right now we can’t see any). You can read more
iMac reviews here.
The idea of a 5K 27in iMac for less than £1,500 might sound
attractive, but we’d advise that you think twice about that model,
equipped as it is with a standard (slow) hard drive. Essentially the
only difference between that model and the one above it is that for £150
you get a must-have Fusion Drive and a slightly better graphics card.
Spend the extra and get the £80 Fusion Drive when you purchase this model. We’d also advise that spend £160 and upgrade to 18GB RAM as well.
