The T2 chip marks the start of a Mac revo­lu­tion

Sure, it’s the fastest Mac ever made, but the T2 chip is what re­ally makes it dif­fer­ent. Ja­son Snell re­ports

Macworld - - Contents -

I’ve spent the past week with Ap­ple’s new imac Pro, and in most ways it’s just a faster Mac. It’s the first pro Mac desk­top in over three years and the fastest Mac yet made, granted, but still en­tirely fa­mil­iar. And yet in many ways – some no­tice­able, some en­tirely in­vis­i­ble – this new Mac is com­pletely dif­fer­ent from all past Mac mod­els.

The imac Pro may be an out­lier today, but in the fu­ture we’ll prob­a­bly look back on it as the start of a new era for the Mac, all be­cause of the Ap­ple-built T2 chip it car­ries in­side. Here’s how the T2 makes this imac Pro un­like all other Macs.

The power be­hind the throne

The T2 pro­ces­sor isn’t do­ing the heavy lift­ing in the imac Pro – that’s the In­tel Xeon pro­ces­sor with be­tween 8 and 14 pro­ces­sor cores. The T2 is the brain be­hind that brain, run­ning the sub­sys­tems of the imac Pro from a sin­gle piece of Ap­ple-built sil­i­con. The re­sult is a sim­pli­fied in­ter­nal de­sign that doesn’t re­quire mul­ti­ple com­po­nents from mul­ti­ple man­u­fac­tur­ers.

On most Macs, there are dis­crete con­trollers for au­dio, sys­tem man­age­ment and disk drives. But the T2 han­dles all th­ese tasks. The T2 is re­spon­si­ble for con­trol­ling the imac Pro’s stereo speak­ers, in­ter­nal mi­cro­phones, and dual cool­ing fans, all by it­self.

A Face­time cam­era like no other

The imac Pro’s Face­time cam­era can cap­ture

1080p video, an up­grade from the 5K imac’s

720p res­o­lu­tion. But this new Face­time cam­era is driven by the T2 pro­ces­sor, which means it’s got in­tel­li­gence that pre­vi­ous Face­time cam­eras lacked. Like its cousin pro­ces­sors that drive the iphone, the T2 has an Ap­ple-de­signed im­age sig­nal pro­ces­sor that de­tects faces in or­der to prop­erly set ex­po­sure and white bal­ance, dy­nam­i­cally ad­justs ex­po­sure, and a whole lot more – all in the ser­vice

of pro­duc­ing a bet­ter im­age, just like what hap­pens when you shoot photos or video with your iphone.

What flash stor­age?

The imac Pro of­fers be­tween 1- and 4TB of flash stor­age, also com­monly re­ferred to as an SSD, or ‘solid-state drive’. This is hardly the first Mac to in­clude SSDS, but it’s a very dif­fer­ent ap­proach to stor­age than pre­vi­ous mod­els.

Most solid-state drives, whether they fit into a drive bay like a spin­ning hard drive or are re­duced to a chip that slides into a slot some­where, are self­con­tained – they’re a bank of mem­ory com­bined with a con­troller. On the imac Pro, though, that’s

not the case – the SSD that comes with the imac Pro is ac­tu­ally two banks of NAND mem­ory. (Ev­ery imac Pro has two banks that are ‘stripped’ to­gether into a sin­gle drive – if you get the 1TB model, your imac Pro has two 512GB NAND banks; the 4TB model has two 2TB NAND banks.)

As for the disk con­troller? There isn’t one – or more ac­cu­rately, the disk con­troller is built into the T2 it­self. This gives the T2 com­plete con­trol over in­ter­nal stor­age on the imac Pro. This has some ma­jor ben­e­fits in terms of speed and se­cu­rity.

Ev­ery bit of data stored on an imac Pro’s SSD is en­crypted on the fly by the T2, so that if a ne­far­i­ous per­son tried to pull out the stor­age chips and read them later, they’d be out of luck.

(For ad­di­tional se­cu­rity, Ap­ple strongly sug­gests you turn on Fil­e­vault, which ties SSD en­cryp­tion to your pass­word. This pro­vides an ad­di­tional level of se­cu­rity, be­cause your disk can’t be de­crypted with­out the proper hard­ware and your pass­word.)

All this en­cryp­tion hap­pens in­vis­i­bly, so the SSDS in the imac Pro still op­er­ate at full speed – ap­prox­i­mately 3GB per sec­ond.

Boot twice for safety

You know you’re a Mac nerd when you have opin­ions about the keys you need to hold down when re­boot­ing while trou­bleshoot­ing a prob­lem. But on the imac Pro, boot­ing and re­boot­ing is dif­fer­ent – very dif­fer­ent. In essence, it’s a twostage process, first driven by the T2, then driven by the more tra­di­tional sys­tem boot process.

When you start up the imac Pro, the fa­mil­iar Ap­ple logo ap­pears. This is a sign that the T2 is tak­ing con­trol. For se­cu­rity rea­sons, the T2 is the imac Pro hard­ware’s ‘root of trust’, and it val­i­dates the en­tire boot process when the power comes on. The T2 starts up, checks things out, loads its boot­loader, ver­i­fies that it’s le­git­i­mate and cryp­to­graph­i­cally signed by Ap­ple, and then moves on to the next part of the boot process.

This new boot process means there’s also a new util­ity for Mac users to get to know: Startup Se­cu­rity Util­ity, which you can only ac­cess by boot­ing into Re­cov­ery mode by hold­ing down Com­mand-r while start­ing up. Startup Se­cu­rity Util­ity gives the T2 guid­ance about just how strict it should be when judg­ing whether it should boot your com­puter. By de­fault, se­cu­rity is set to Full, which means that only the cur­rent op­er­at­ing sys­tem or an­other OS ver­sion signed and trusted by Ap­ple – mean­ing it hasn’t been tam­pered with in any way – can be booted by the com­puter. This ver­sion re­quires a net­work con­nec­tion when you at­tempt to in­stall any OS soft­ware up­dates, be­cause it needs to ver­ify with Ap­ple that the up­dates are

le­git­i­mate. You can also set the se­cu­rity level lower, to Medium (which al­lows older ver­sion of macos to run re­gard­less of Ap­ple’s level of trust), or turn the fea­ture off en­tirely, em­u­lat­ing the way all other Macs cur­rently start up.

(This goes for Boot Camp, too – the T2 re­spects Mi­crosoft’s sign­ing au­thor­ity for Win­dows 10 be­gin­ning with 2017’s Fall Cre­ators Up­date, so Boot Camp users can re­boot into Win­dows 10 while re­main­ing fully se­cure.)

A hy­brid Mac? Not quite.

Be­fore the imac Pro was re­leased, there was a lot of spec­u­la­tion that it was part of a trend to­ward cre­at­ing a ‘hy­brid Mac’ that is driven by both an

In­tel pro­ces­sor and an Ap­ple-de­signed ARM chip like those found in other Ap­ple de­vices. The imac Pro is def­i­nitely a hy­brid of a sort, but prob­a­bly not the one peo­ple were ex­pect­ing. With the T2, Ap­ple is us­ing its chip-de­sign prow­ess to take more con­trol over parts of the Mac hard­ware that were pre­vi­ously out­sourced to other con­trollers, and reap­ing the ben­e­fits of in­te­grat­ing them all to­gether.

The imac Pro isn’t run­ning IOS apps, but it does get to take ad­van­tage of most of the work Ap­ple has done to bol­ster the se­cu­rity of IOS de­vices and en­hance the qual­ity of photos and video taken by iphone cam­eras. Ap­ple will al­most cer­tainly con­tinue to push this tech­nol­ogy into more fu­ture Mac mod­els, be­cause it al­lows Ap­ple to use the work it’s al­ready done on IOS to im­prove the fea­tures and se­cu­rity of the Mac.

In ad­di­tion to all this ex­ter­nal I/O, the imac Pro has crazy­fast striped SSDS, en­crypted and con­trolled by the T2

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.