Intel unveils the Thunderbolt 4 spec, which AMD believes it can use – PCWorld

Intel unveiled Thunderbolt 4 on Wednesday, tightening the existing I/O specification for docks, some displays, external storage and GPUs. Bandwidth remains unchanged from Thunderbolt 3, though executives said to expect new types of docks and longer cables. AMD, which has traditionally never associated Thunderbolt with its Ryzen platforms, pooh-poohed Thunderbolt demand but said it meets the specs security restrictions.
Thunderbolt 4 will debut later this year as part of Intels Tiger Lake CPU platform, as Intel originally announced during CES in January. We now know it will support 40Gbps throughput, but with tighter minimum specs. Thunderbolt 4 will guarantee that a pair of 4K displays will work with a Thunderbolt dock, and require Thunderbolt 4-equipped PCs to charge on at least one Thunderbolt port. Thunderbolt PCs will be able to connect to either compact or full docks with up to four Thunderbolt ports. Longer Thunderbolt cables will be possible, too.
One thing that might not change is Thunderbolts exclusivity. Intel developed Thunderbolt with Apple, and perhaps not coincidentally, OEM systems based on rival AMDs CPUs have never had this technology. AMD officials dismissed the need for Thunderbolt, even though officials indicated that they could ship Thunderbolt controllers without the need to integrate them.
IntelThe Thunderbolt technology that Intel and Apple designed originated with Intels Light Peak technology prototype at 2009s Intel Developer Forum.
Whats new in Thunderbolt 4?
Intels still pitching Thunderbolt as a single standard to rule them all, but the reality up to now has been complicated. You still have to squint hard at that USB-C-shaped port to determine which of the multitude of USB specifications it meets, including whether its a USB4 connection that happens to support Thunderbolt. To muddy things further, Thunderbolt also encompasses PCIe, DisplayPort, and USB Power Delivery standards.
Intel
Intels informal message is just look for the Thunderbolt. The small lightning-bolt icon means that port will support everything from USB 3.2 to USB4, and a high-speed Thunderbolt 4 cable will cover all of your bandwidth.
Though Thunderbolt 4 and USB4 share the same underlying protocol, Thunderbolt 4 includes more compatibility requirements than USB4 does. That makes Thunderbolt 4 the complete version of USB-C, according to Jason Ziller, the general manager for Client Connectivity for Intel, in a presentation to reporters.
IntelThunderbolt has long aspired to clean up the mess that is the various USB standards, all using USB-C as a physical interface.
Thunderbolt 4 also seeks to right some wrongs with its predecessor, Thunderbolt 3. For instance, Thunderbolt 3 was supposed to supply enough bandwidth to drive a pair of 4K displays at 60Hz or a single 8K monitor at 60Hz. But not all of them do, Ziller said of the current Thunderbolt 3 docksbecause that specs loose minimum requirements allowed manufacturers to cut corners. Thunderbolt 4 promises to be rock-solid in that regard. In addition, the new spec will transfer at 32Gbps across PCIe (for storage speeds up to 3 gigabytes per second). Its also fully USB4-compliant.
IntelA summary of how Thunderbolt 4 differs from other I/O standards.
Laptops designed with Thunderbolt 4 will be required to offer input charging via a Thunderbolt 4 port, as an alternative to or replacement for proprietary barrel chargers (this is usually true with Thunderbolt 3 ports as well). Though Thunderbolt 3s Ice Lake implementation allowed for Thunderbolt ports to be placed on either side of a laptopa new feature for that platformIntels not yet saying how Thunderbolt 4 ports will be arrayed within Tiger Lake laptops. Laptops with Thunderbolt 4 will be able to accept 100W of input power, and supply 15W externally.
Intels also announcing that Thunderbolt cables, labeled with the lightning-bolt icon and a number 4, will be available in the standard 0.2m and 0.8m lengths, together with an additional 2-meter cable length that Ziller said should cost less than current 2-meter cables. Theres even a new optical Thunderbolt 4 cable design, with lengths ranging from 5 to 50 meters, that Ziller said he expects will be shipped sometime next year.
New Thunderbolt docks on the horizon
While Intel will supply its own Thunderbolt 4 solution as a selling point for Tiger Lake systems, it will also sell its own host silicon (Maple Ridge, specifically the JHL8540 and JHL8340 chips) as well as device silicon (Goshen Ridge, also known as the JHL8440). Thunderbolt 4 will also play a role in Intels ongoing Project Athena collaboration with PC vendors to develop premium thin-and-light notebooks.
IntelAn example of some Thunderbolt 4 docks.
Peripherals will evolve, too. Were already seeing compact docks like Belkins Thunderbolt Dock Core, including some that are strictly bus-powered, in addition to larger, bulkier, more full-featured docksRemove non-product link manufactured by Lenovo and others. Intel says the key feature for these new Thunderbolt 4 docks will be four Thunderbolt ports for connecting multiple devices, in either a tree structure, or by daisy-chaining them. Thunderbolt 4 host PCs will be backward-compatible with existing Thunderbolt 3 docks.
Thunderbolt ports have gradually gained ground. According to Ziller, hundreds of millions of PCs and PC accessories have shipped with Thunderbolt 3 silicon inside. Thunderbolt docks are rising, too: Intel projects 20-percent growth, versus the 10-percent annual growth of cheaper, slower USB-C hubs. 
Displays have been slower to pick up the technology. Ziller suggested wed see more with Thunderbolt 4, though he couldnt say when or in what quantity.
Can AMD use Thunderbolt 4?
Theres one final wrinkle. One of the requirements for Thunderbolt 4 is that a laptop vendor must support whats known as Intel VT-d based direct memory access (DMA), a security measure that protects the system by preventing direct memory access to preassigned domains. Because VT-d based direct memory access (DMA) is strictly an Intel technology, however, this requirement seemingly creates a barrier for AMD.
If nothing else, the rival chipmakers seem aligned in their desire to skirt the issue. I wouldnt read it as its only Intel, because of VT-d, Ziller said. If

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