repoman27

The Haswell iMacs support both "normal" 1.5 V DDR3 and "low voltage" 1.35 V DDR3L SODIMMs. In order to operate at the lower voltage level (which consumes less power and generates less heat), you must use all DDR3L modules, otherwise they will operate at 1.5 V since the memory bus can only be driven at a single voltage.

DSL3510L "Cactus Ridge" all around again this time. Andrew was kind enough to post links to some close-ups in the comments section of this blog post.

I have an early 2008 MBP, and it is very picky about booting Linux. I too have wasted many an hour messing around with various distros and bootloaders only to wind up frustrated. However, AFAICT it is due to the NVIDIA dGPU and chipset, not an evil plot by Apple. I recently booted Ubuntu 18.04 Bionic Beaver from a USB thumb drive successfully by simply adding the nomodeset boot option. You may want to give it a try if you’ve still got that hardware kicking around.

But I can pretty much guarantee that if there is a chip called T2 in the MBPs from that era, it shares absolutely no lineage with the current T2.

I’d reckon it’s a complete redesign to be (more) compliant with the latest USB Power Delivery Specification Rev. 3.0, Version 1.2. That might have ramifications for charging iOS devices from these newer power adapters. AFAIK, Apple’s proprietary divider methods are no longer allowed, and to get certification, chargers must provide power according to the USB Battery Charging 1.2 spec instead.

I imagine this model also supports all of the normative voltage and current levels expected of a 60W USB Type-C charger according to the latest specs. So it probably provides better interoperability with non-Apple devices.

It may also include a programmable power supply. Hopefully someone manages to coax Benson Leung or Nathan K. into doing a little write-up on this.

Newer specs often adopt and standardize features that already existed as proprietary extensions to the previous version. Thus a quick firmware or driver update can bump up the revision number because some of those features were already supported by the silicon. (e.g. 802.11a/b/g hardware that included “draft n” features could become 802.11a/b/g/n via a software “enabler”. ) That appears to be the case with this USI module and Bluetooth 4.2 > 5.

It is incredibly unlikely that this module contains certain functionality necessary to implement the more compelling aspects of 802.11ax. In particular, OFDMA isn’t something that can just be bolted on via a firmware update.

Apple’s use of 3x3:3 Wi-Fi modules in MacBook Pros already makes them 50% faster than any integrated laptop solution from other vendors.

@Raoul H, 4 spatial streams are supported under 802.11ac, but usually only by access points. Apple is the only OEM I am aware of to ship a laptop with support for more than 2 spatial streams.

@JJ Wu The SSD in the iMac, Mac Pro, MacBook Air, and MacBook Pro (Late 2013 - 2015) is a PCIe SSD with a proprietary form factor and connector. If you have installed macOS 10.13 High Sierra or later, the firmware will be updated to unofficially support 3rd party NVMe PCIe SSDs. Then you can use an adapter to physically convert from Apple’s proprietary interface to M.2 2280 or whatever and replace the drive. Third party solutions emulating Apple’s form factor and connector are also available for these models.

That is not at all the case for the *iMac Pro*. No adapter exists because the NAND flash modules are not independent drives and are not connected to the T2 via PCIe. Look at the iFixit teardown of the iMac Pro. Try searching for an adapter or third party SSD upgrade solution. You will not find one.

@Karl B I’m guessing it’s to assist with continuity features. Like if you’re wearing an Apple Watch, you can just sit down at your MacBook Pro and it will unlock for you. https://support.apple.com/en-us/ht204681 I believe this also works via Bluetooth by calculating time of flight, but NFC is probably easier / more secure.

@JJ Wu, The SSD controller is in the T2. To quote Apple: “Introducing the Apple T2 chip, our second-generation custom Mac silicon. By redesigning and integrating several controllers found in other Mac systems — like the system management controller, image signal processor, audio controller, and SSD controller — T2 delivers new capabilities to the Mac.”

The notion that the iMac Pro used independent drives in RAID 0 is a widely held misconception that is entirely inaccurate. Look at the packages on the modules. They are commodity multi-chip NAND packages that connect to the SSD controller in the T2 using a typical NAND bus architecture. This is essentially the same SSD as in the iMac Pro but the NAND packages are on the logic board instead of on independent modules.

External displays are always driven by the discrete GPU on the 15-inch, so there is still hope there. I believe the internal display is connected to the Intel integrated GPU via eDP to allow graphics switching, but 4 DisplayPort main links from the AMD GPU feed the two Thunderbolt controllers.

To elaborate on what Dan said, the T2 chip includes Apple’s own NVMe PCIe SSD controller, which they developed in house. Like most SSD controllers, it uses multiple channels (maybe 8 in this case?) to address the NAND flash dies and increase performance through parallelism. Both the T2 and the NAND flash packages are soldered directly to the logic board. It is also likely that the drive can tolerate the failure of individual blocks and pages, or perhaps even whole NAND dies by using parity data.

This is a different concept than RAID though, which employs Redundant Arrays of Independent Drives to increase availability and in some cases performance. RAID 0 in particular ditches the redundant bit and stripes across an array of independent drives purely for increased performance. Apple decided to put the NAND flash packages for the iMac Pro on a pair of removable modules, however they were in no way independent drives. There was still only a single SSD controller located in the T2 chip on the logic board.

Looks like one of the Thunderbolt ports on the right-hand side, probably the one closest to the headphone jack, is connected to the T2 by way of a USB switch. This is probably the port that is used to perform a DFU restore of the iBridge, like on the iMac Pro ( https://help.apple.com/configurator/mac/... ) It’s possible that data recovery could also be performed via that Thunderbolt port given the right tools.

Yep, 10/100/1000BASE-T Ethernet PCIe Controller with ASF2.0.

“The device combines a triple-speed IEEE 802.3-compliant Media Access Controller (MAC) with a triple-speed Ethernet transceiver, x1 PCIe bus interface and on-chip buffer memory in a single device. The device is fabricated in 1.2V CMOS process, providing a low-power system solution.”