What is the AMD Ryzen Threadripper 3970X

Threadripper 3970X & 3960X in the test: AMD's large Ryzen bury Intel Core X.

tl; dr:With Ryzen Threadripper 3970X and 3960X, AMD is straightening the relationship between its own HEDT and mainstream platform. The new CPUs still offer “only” 32 and 24 cores, but thanks to the switch to Zen 2 and the chiplet design, they still have increased by 50 percent. Intel Core X no longer sees any land there.

AMD Ryzen is followed by AMD Ryzen Threadripper - now in its third generation. After AMD raised the bar for the number of cores from up to 16 for Threadripper 1000 to up to 32 for Threadripper 2000 in the past two years and finally launched its own high-end product again, the new generation is now At least for this year the switch to Zen 2 is in focus. The two variants presented today, 3960X and 3970X, remain with a maximum of 32 cores, but almost everything else is upgraded so much that in benchmarks it appears as if another "core upgrade" had taken place. The gain in performance is breathtaking in places. And in other places, too, the air stayed away from time to time during testing.

Technical data compared to the predecessor

The Ryzen Threadripper 3970X with 32 cores replaces the Ryzen Threadripper 2990WX with 32 cores, the 3960X with 24 cores the 2970WX with 24 cores. But anyone who concludes that comparatively little is happening is fatally mistaken.

With the change to the new I / O die chiplet design and Zen 2, not only is the fast L3 cache doubled and the memory interface can handle faster memory, there are also much higher clock rates on a 7 nm basis and the drastically increased IPC, with which Ryzen 3000 could already score. AMD puts the IPC gain alone at 15 percent; the clock rate increase is around 20 percent even in real everyday life thanks to the additionally increased TDP to 280 watts. And if all of this is combined, the test in multi-core applications actually results in processors that are 50 percent faster on average.

But this is not the end of the story. As AMD announces parallel to the case of the NDA for 3970X and 3960X, there will be a Ryzen Threadripper 3990X with 64 cores at 280 watts TDP in the coming year. None of these CPUs has the “W” for workstation in their name, which was only introduced last year.

As with all 3000 series processors from AMD, there is also growth with Threadripper in terms of price. 100 or 200 US dollars surcharge before taxes for the Threadripper 3000 compared to its direct predecessor in the USA, in Germany it is as much as 200 or 360 euros. And that happens not only because the performance increases so much, but also with a view to Epyc. There are the two single-socket versions Epyc 7402P and 7502P with the same number of cores, less clock and TDP but octa-channel RAM for 1,250 and 2,300 US dollars. By dumping the price, AMD would primarily harm itself here. Danger from Intel? Not threatening at the moment.

The chiplet design perfected

The biggest novelty from AMD with the introduction of Zen 2 was next to 7 nm the chiplet design. Multi-chip processors with usually identical This existed before, but it is now taking a completely new approach. Presented to the press for the first time in November 2018, this now runs through all new solutions from small with only two chips (1 × I / O die, 1 × CPU chiplet) per package to large with nine chips on one carrier (1 × I / O die, 8 × CPU chiplet).

AMD uses many similarities and the resulting synergies that simplify the entire process and save a lot of money in the long term. For example, every CPU die is identical, regardless of whether it is used in the smallest Matisse or in the largest Epyc. Since the Zen 2 generation, a CPU die has always had eight cores and 32 MB L3 cache, the so-called chiplets are then combined with others and result in the finished end product.

The CPU dies always include an I / O die in which the memory controller and PCIe lanes are located. This is exactly where the biggest difference lies between the small mainstream products on the AM4 socket and the high-end models on the SP3 / sTRX4 socket.

Threadripper 3000 is almost an Epyc "Rome"

The I / O die from Epyc 2 "Rome" and now also Threadripper 3000 "Castle Peak" is a giant. Globalfoundries accommodates 8.34 billion transistors in 12 nm production on a 412 mm² chip. For comparison: the consumer I / O chip for Ryzen 3000 has a weight of only 2.09 billion transistors and occupies 125 mm².

The dies, each with eight CPU cores, are even smaller at 74 mm², even though 3.8 billion transistors are installed there too. The much finer 7 nm production from TSMC plays an important role here.

The I / O dies (IOD) from Castle Peak and Rome are identical, but not the same for the area of ​​application. Because at least the first two Threadripper 3000 do not use all eight built-in memory controllers (left and right on the edge in the picture), only half are provided, so eight channels become four. The halving continues elsewhere: Of the 128 PCIe 4.0 lanes of the IOD (visible above and below in the middle), Threadripper is only allowed to use 64. With Rome there are a full 128 lanes per CPU, 64 of which are used for communication between the CPUs in the dual socket setup, so a total of 128 remain free.

Threadripper 3960X and 3970X consist of five chips

Both thread rippers use four CPU chips with eight cores per CPU die (CCD). With the 3970X all four are fully activated, with the 3960X two cores are deactivated in each CCD, but the cache is retained in full size. The two fastest cores, i.e. those that can drive the highest turbo rate, are always located in the CCD4 according to the hierarchy. As before, the four CCDs are connected to the large I / O die via the Infinity Fabric.

New platform with new old socket LGA 4096

LGA 4096 has been the name of the socket for AMD's high-end solutions since the first hour of Zen and it remains the same with Threadripper 3000, but the dog is buried in the details. Because the new processor is not functionally compatible with the previous socket, although it is mechanically. However, the pin assignment was almost completely changed, so a new model cannot work in the old socket or vice versa. On the other hand, old and new CPUs can be installed on the wrong platform.

AMD explained the motivation with the lack of scalability of the socket TR4, which is now becoming sTRX4. AMD had apparently castrated the original socket and the boards so heavily that there was now no other option than to make it completely new, while Epyc on socket SP3 in the new Rome generation without any problems on a two-year-old mainboard of the first generation is working. At least AMD's roadmap for the new Threadripper socket indicates that it will also be used in the next generation - "Subject to Change"Notice included.

New chipset TRX40 for considerable luxury mainboards

A new socket requires new mainboards. The logical consequence: an adapted new chipset ("TRX40") is included if everything has to be redone anyway. The result is the best-equipped circuit boards that have existed so far, because they combine the various ports of the CPUs, more precisely of the I / O dies, with the chipset.

The equipment of the new high-end platform from AMD has no competition. Due to the same architecture as in the mainstream desktop, the CPUs offer the same features, but since the I / O die is one stage larger, the connections are also more. Some of the 64 PCIe lanes of the I / O-Dies are reserved, others are intended directly for storage. In the end, however, there are still 48 freely usable lanes left - three PCIe x16 slots can be fully controlled in accordance with the PCIe 4.0 standard. In addition, additional 2 × 4 PCIe lanes can be used as such or to connect NVMe drives or 2 × 4 SATA ports. In total, there are 56 usable PCIe lanes of the CPU.

The actual chipset TRX40 is nothing more than the X570 for the high-end platform - the X399 corresponded to the X370 in the predecessor. The TRX40 chip built in 14 nm at Globalfoundries with a TDP of 15 watts maximum, which is the I / O die of the Matisse processors, offers the same connections as the X570 chipset for the AM4 socket. In order to do justice to the high-end platform, the connection to the processor with eight lanes is twice as wide as on the mainstream level. A maximum of 16 PCIe 4.0 lanes can be used directly from the chipset in a variety of ways, for example there are a maximum of twelve SATA ports on the X570 as well as four regular plus eight fast USB interfaces. In total with the CPU, the 72 PCIe lanes advertised by AMD according to Standard 4.0 result for the platform.

Supports up to 256 GB of RAM

Since the I / O die is practically the same everywhere, the memory configurations are also the same. Threadripper now also benefits from high clock rates, even when using large dual-rank modules. The officially supported speed only drops when it is fully equipped - but this does not prevent everything from being clocked to the same previous level. The new storage controller had already proven to be much better than before with Matisse.

Theoretically, the TRX40 platform also supports ECC error correction. In the end, however, it is always up to the motherboard manufacturer whether they also support this with a suitable BIOS. This has often been a problem in the past.

It's going to be expensive fun!

AMD's new high-end platform not only sets a new milestone in history in terms of performance, the price has also increased significantly. And while the CPU surcharges remain realistic for what's on offer, the mainboards will be an expensive undertaking. Many manufacturers of the boards have really been able to live their lives here, the challenge for the customer is now to find a board in affordable regions at all. Anyone who would have thought two years ago that the X399 motherboards, which cost between 300 and 400 euros, were already expensive, will not even get the cheapest from the successor. And this time there are really no upper limits.

The price for the cheapest complete package consisting of CPU, board and at least one quad-channel memory kit is well above the 2,000 euro mark at the start of November 2019. Maxed out 4,000 euros are possible without any problems, because 256 GByte DDR4-3200 can easily be installed in addition to the CPU of 2,150 euros - and they also cost at least 1,200 euros. Before the fall of the NDA, it wasn't clear what the most expensive board would cost. Just under four digits should be set.

And that's not the end of it, because 64 cores will come next year. The surcharge for the then once again clearer sole ruler in the market segment is likely to be enormous. An official price and a statement as to whether the Ryzen Threadripper 3990X will switch platforms again, does not yet exist.

On the next page: Benchmarks in applications and games

  • Volker Rißka Email
    ... has been writing about CPUs, their architectures and manufacturing processes as well as mainboards and RAM since 2002.
  • Jan-Frederik TimmEmailTwitter
    ... is a graduate engineer and has been writing on ComputerBase since 2001 about the latest hardware, macOS and Windows.