Ryzen Test Article

Michael Belcher

Introduction: AMD Ryzen’s Backstory

Regardless of your processor preference, there is no denying the impact that AMD’s Ryzen processor series had on the computer industry. Not long ago, we were accustomed to quad core processors and the annual refresh year after year. While higher core counts existed in other segments such as HEDT (High End Desktop) and the HPC (High Performance Computing) server markets, we saw very little of that technology trickle down to the average consumer. Enter AMD’s Ryzen design. Starting from scratch, AMD managed to create a scalable design that improved their manufacturing yields while offering fantastic performance for a relatively low cost.

 

While the initial design had some hurdles to overcome, the launch of the 1st generation Ryzen processors back in March of 2017 created a large ripple throughout the industry that is still felt to this day. AMD had proven that consumers wanted more than just the same product every year. They blurred the line between the consumer and workstation market segments and pushed the entire industry forward, resulting in a resurgence of competition that was sorely missed by consumers for quite some time. Intel, AMD’s largest competitor in the desktop processing market, had to adapt quickly to AMD’s Ryzen design. Their initial reaction consisted of increasing the core count of their processors, followed by adding Hyperthreading support for processor families that lacked the technology in previous generations. For the first time in many years, we saw a pivotal change for AMD, and a real wake-up call for the industry-leading Intel.

 

AMD came out swinging with their 1st generation Threadripper processors, offering 16 cores and 32 threads for $999. While it did not outperform Intel’s flagship at the time, the 18 core, 36 thread Core i9 7980XE, it offered very competitive performance for nearly half the price. As time went on, Intel refreshed their Skylake-X lineup with minor improvements to the TIM (Thermal Interface Material) and a slight boost in clock speeds. AMD, refusing to rest on their laurels, launched their 2nd generation Threadripper CPU’s. The flagship Threadripper 2990WX offered 32 cores, 64 threads, nearly doubling that of Intel’s 18 core, 36 thread 9980XE while still priced $200 cheaper at launch. This sent a clear message to Intel that AMD was no longer the “cheap alternative” and that their processors had real power to bring to the table. Intel still had a very key advantage in their IPC (Instructions Per Clock) performance and their overall higher clock speeds which helped distinguish the 9980XE in mixed workloads where both clock speeds and overall core count scaled well together, however AMD still had plans to close that gap. This plan came to fruition in the form of Zen 2 with the launch of the Ryzen 3000 series processors.

Michael Belcher

Ryzen Today

The launch of the Zen 2 architecture came in the form of the Ryzen 3000 series processors. Not only were consumers greeted with more cores than the previous generation, they received a very noticeable performance boost as well compared to the original Zen and Zen+ architectures. A 15% increase in IPC helped close the gap on single core performance while further extending AMD’s performance lead in multi-threaded applications. This, along with AMD’s improved memory controllers helped solidify Ryzen as a serious competitor to Intel, even in the gaming market. While Intel’s clock speed advantage allowed them to maintain the “best gaming processor” crown, it quickly became apparent that the higher clock speeds were difficult to maintain as more processing cores are added to the equation. As the clock speeds between Intel’s HEDT platform started to resemble the clock speeds of AMD’s Threadripper platform, AMD’s core count advantage made itself abundantly clear that the HEDT market did not belong solely to Intel. For the first time in a very long time, AMD managed to take the performance crown in this market. With all of that aside, let’s talk specifications.

 

Threadripper 3000 Series Pricing & Specifications

	AMD Ryzen™ Threadripper™ 3960X	AMD Ryzen™ Threadripper™ 3970X	AMD Ryzen™ Threadripper™ 3990X
Price	$1399	$1999	$3990
Cores/Threads	24C/48T	32C/64T	64C/128T
Base/Boost Clocks	3.8GHz / 4.5GHz	3.7GHz / 4.5GHz	2.9GHz / 4.3GHz
Cache Quantity	12MB L2 Cache 128MB L3 Cache	16MB L2 Cache 128MB L3 Cache	32MB L2 Cache 256MB L3 Cache
TDP	280W
CCD Configuration	4x 6-core CCDs	4x 8-core CCDs	8x 8-core CCDs
Transistor Count(s)	~3.9 billion per CCD ~8.34 billion for IOD
Die Size(s)	74mm² per CCD 416mm² per IOD
Lithography	7nm for CCDs (TSMC) 12nm for IOD (GloFo)
Socket Compatibility	Socket sTRX4 (LGA 4094)
Required Chipset	AMD TRX40 (15W peak TDP / 14nm GloFo)
Core Architecture	AMD Zen 2
CPPC2 Fastest Cores	2x in CCD4
Socket Power Infrastructure	280W PPT, 300A EDC, 215A TDC

 

This review will focus specifically on the Threadripper 3990X, however it’s important to understand exactly where it sits in the rest of the Threadripper 3000 product stack. AMD is offering a 24 core, 48 thread 3960X as the entry level processor for this platform. AMD had previously offered a 16 core Threadripper as their entry level processor for this platform, but that role has been fulfilled by the Ryzen 9 3950X on the consumer X570 platform. It makes sense to start off at 24 cores and scale the stack up from there. Next, we have the 32 core, 64 thread 3970X which sits in the middle of the stack. Prior to the launch of the 3990X, it was the king of HEDT and still offers insane performance for its asking price. Lastly, we have the main event, the Threadripper 3990X. Boasting 64 cores, 128 threads and a massive 256MB cache, it’s unlike anything on the market.

Michael Belcher

3rd Generation Threadripper: A closer look under the hood

Looking at the numbers on paper, it’s easy to see why the 3rd generation Threadripper CPU’s are dominating the HEDT market, but it’s important to understand exactly why, and how AMD managed to pull it off. One of the key areas to their success was the topology of their 3rd generation Ryzen processors. As with the previous Ryzen generations, AMD is using an MCM or Multi-Chip Module design over the single, more traditional monolithic die. The biggest difference with this generation of Ryzen processors is that AMD has moved their central IO functions off the processor die, and on to its own I/O die.

As you can see in the image above, there are multiple CCD’s or Core Chiplet Die’s that contain the Zen 2 CPU cores and their respective L3 caches. All of this is connected to a central I/O die that is responsible for providing each CCD access to PCIe lanes and system memory. You will likely notice that there are multiple memory controllers on this I/O die, and that everything is weaved together by small blocks marked with the infinity symbol ∞. This symbol represents AMD’s Infinity Fabric, a high-speed interconnect through which all these dies are woven together. This unique design also allows AMD to scale their processors in a very dynamic manner as they can simply pick and choose each CCD configuration for their processors. It also allows AMD to improve their yield rates and reduce waste by using the dies that didn’t perform to their original standards in a different capacity.

 

The current 3rd generation Threadripper product stack is a great example of this in effect. For an example, let’s say AMD designed a 32 core Threadripper with a 4x 8-core CCD configuration. Let’s also say that in the process of picking out the best 8-core dies, they noticed that some of the cores were unable to meet the standards that they designated for this 32-core processor. Instead of throwing away the dies and wasting silicon, AMD can modify the dies and design a 4x 6-core CCD configuration to create a 24 core Threadripper. The improved yields and waste reduction aside, this also plays an important role in filling a void in a market. Without this practice, you may end up with a wider product stack with a wider gap of prices and nothing to fit in between, making it difficult for consumers to find the best product for their budget.