Following the launch of Thunderbolt 4 earlier this year as part of Intel's Tiger Lake CPUs, the next piece of the TB4 hardware stack has dropped this week with the release of Intel's first stand-alone Thunderbolt 4 controller, Maple Ridge (JHL8540). Previously announced back in July as part of Thunderbolt 4's reveal, Intel this week updated their Ark database to add a product page for the Maple Ridge controller family and flag that the first part is now shipping. With the release of the discrete Thunderbolt 4 controller, it will now be possible for hardware vendors to build TB4 hosts with additional ports, or in devices not using Intel's Tiger Lake Silicon.

This late-December launch follow's Intel's previous roadmap, which had the launch of standalone controllers set to take place before the end of 2020. These included the Goshen Ridge (JHL8440) device controller – for use in docks and peripherals, and the Maple Ridge (JHL8540 and JHL8340) host controllers – for use in computers, tablets, and other client devices. Goshen Ridge went into production soon after the announcement. And with the release of Maple Ridge Intel has also kept its promise here, getting it out just prior to the end of the year.

For quite some time, Thunderbolt ports were found only on systems with Intel processors. However, last year we saw vendors such as ASRock innovate with the introduction of a Thunderbolt 3 port on the X570 Phantom Gaming-ITX/TB3, an AMD Ryzen platform motherboard. This was followed a few months back by the introduction of M1-based Macs featuring Thunderbolt 3 (backed by Apple's in-house controllers). The use of Maple Ridge will now enable motherboard vendors to create systems with Thunderbolt 4 ports that do not necessarily need to be based on Intel processors.

The JHL8540 Maple Ridge controller interfaces with the host processor using a PCIe 3.0 x4 link and also takes in two Display Port 1.4a inputs. On the downstream side, the controller enables two Thunderbolt 4 ports, which along with their native Thunderbolt (packet encapsulation) abilities can also be used as straight-up USB4 ports, or as DisplayPorts via USB-C's DP alt mode.

The PCIe switch and, in general, the PCIe support in Maple Ridge has been updated to work with many optional features, keeping security in mind and the rich variety of PCIe devices coming into the market. For example, Maple Ridge includes PCIe peer-to-peer support which allows two PCIe devices connected to the two Thunderbolt 4 ports to exchange data with each other without having to make it travel upstream to the host RAM. From a security viewpoint, Access Control Services (ACS) is also supported to provide isolation between different sets of PCIe devices and make them always go through the IOMMU. Precision Time Measurement (PTM) is also a supported feature, allowing different downstream PCIe devices to accurately synchronize with each other and the host system.

It must be noted that Thunderbolt 4 brings more guaranteed bandwidth to end-users. With Thunderbolt 3, device vendors could skimp on the connection of the controller to the host processor – using only a PCIe 3.0 x2 upstream link instead of PCIe 3.0 x4, but still obtain Thunderbolt 3 certification. This reduced the minimum available PCIe data bandwidth to just 16 Gbps. With Thunderbolt 4, that is no longer possible. Vendors are mandated to use a full PCIe 3.0 x4 link if they desire Thunderbolt 4 certification. Thunderbolt 3's bandwidth sharing mechanism between video and data also put in some dampeners – even in the absence of tunneling DisplayPort streams, 18 Gbps of bandwidth was always reserved for video traffic, and only 22 Gbps available for actual data transfer. Thunderbolt 4 apparently fixes that with up to 32 Gbps of data traffic (full PCIe 3.0 x4 bandwidth) available, allowing devices such as Thunderbolt 4 SSDs to provide 3GBps+ speeds.

Intel has not published official pricing of the new Maple Ridge controller, however Mouser Electornics is listing the controllers for as cheap as $11.34 in bulk quantities. As for the availability of devices featuring the JHL8540, I suspect we're going to see them sooner than later. Intel's next-generation desktop platform, Rocket Lake-S, is not expected to have built-in support for Thunderbolt 4, as this feature was noticeably absent from Intel's Rocket Lake reveal back in October. So adding Thunderbolt 4 to Rocket Lake-S will likely require using Maple Ridge.

This would be consistent with other documentation from Intel, such as the Intel 500 series chipset guidelines, which apparently point to instructions to use a discrete USB4-compliant Intel Thunderbolt 4 controller connecting to four PCIe 3.0 lanes from the chipset for USB4/Thunderbolt 4 support. To that end, we expect that the development of actual hardware by Intel’s partners using the Maple Ridge controller should be well under way by now.

Source: Intel

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  • Deicidium369 - Sunday, December 27, 2020 - link

    TB4 is a certification - it certifies that both the TB3 and USB4 are in compliance with the standards and support a minimum level of implementation of those 2 technologies.

    One can assume that Intel's TB4 controller would receive TB4 Certification.
  • at_clucks - Sunday, December 27, 2020 - link

    @lilkwarrior, indeed there are AMD boards with TB, I own one. But the lack of certification means the controller won't end up integrated in an AMD CPU making it easier for OEMs, and that same missing certification also makes OEMs a bit less than excited about implementing it.

    AMD hinted several times that users don't want TB and that may be true at the low end but anyone buying higher end board and CPU combo would definitely go for it.
  • Deicidium369 - Sunday, December 27, 2020 - link

    "Indeed, this being said the refusal to certify TB on competing platform even after it was proven to be working could be seen as an anti-competitive move. Imagine if AMD just decided to do CPU detection in the driver and refuse to boot if an Intel CPU is detected"

    1st of all - where is any evidence at all that Intel is refusing to certify TB4 on AMD platforms.

    2nd - So AMD is moving in to the OS space - with a competitor to MS Windows - since that would be the only way to keep a system from booting when an Intel CPU is detected - and last I looked AMD has nothing to do with Intel Chipsets for motherboards... And what "driver" would that be again?
  • at_clucks - Sunday, December 27, 2020 - link

    @Deicidium369, the evidence is a Google away. It's faster than asking. If you can't get it right I am certainly willing to assist.

    Secondly, AMD also makes [size=369]GPUs[/size]* not just CPUs. From a technical standpoint it's perfectly possible to have the GPU driver throw a spanner in the works in any number of ways.

    Oh I wish TheinsanegamerN were here to tell me all about those techie ATers who need someone to tell them AMD makes GPUs and they need drivers. All good. Carry on.

    *Too bad AT doesn't support any "advanced" features like text formatting...
  • whatthe123 - Sunday, December 27, 2020 - link

    All I can find is that intel confirmed TB4 works on AMD boards if AMD provides equivalent DMA (which AMD confirmed they do), and that they have certified TB on a few AMD boards already. They also started allowing 3rd parties to make their own TB controllers that have been used on AMD boards. When did they say they will not certify controllers to work on AMD platforms?
  • phatboye - Sunday, December 27, 2020 - link

    Pretty sure that AMD Radeon 6000 series currently do not support SAM on Intel platforms.
  • at_clucks - Tuesday, December 29, 2020 - link

    Not quite the same thing, SAM is a proprietary technology while TB is ostensibly open to competition and royalty free. Except that Intel retained the certification and so far it's been done with the sole purpose of not certifying any implementation in an AMD CPU. OEMs have some freedom hence my MB can have TB.

    For the consumer it would be vastly better to have it actually free, like Intel insists it is in marketing materials. It's a good tech. I'm also certain SAM will be available to Nvidia and Intel in a generation or so.
  • headeffects - Thursday, December 24, 2020 - link

    That would be a new version of thunderbolt, ie TB5. 4 is just rolling out.
  • LiKenun - Friday, December 25, 2020 - link

    Then they'd better quadruple the current speeds since they didn't double the speed as with previous generations.
  • Deicidium369 - Sunday, December 27, 2020 - link

    TB4 is the same speed as TB3 - TB4 is a Certification.

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