Author:
Subject: Processors
Manufacturer: Various

Application Profiling Tells the Story

It should come as no surprise to anyone that has been paying attention the last two months that the latest AMD Ryzen processors and architecture are getting a lot of attention. Ryzen 7 launched with a $499 part that bested the Intel $1000 CPU at heavily threaded applications and Ryzen 5 launched with great value as well, positioning a 6-core/12-thread CPU against quad-core parts from the competition. But part of the story that permeated through both the Ryzen 7 and the Ryzen 5 processor launches was the situation surrounding gaming performance, in particular 1080p gaming, and the surprising delta  that we see in some games.

Our team has done quite a bit of research and testing on this topic. This included a detailed look at the first asserted reason for the performance gap, the Windows 10 scheduler. Our summary there was that the scheduler was working as expected and that minimal difference was seen when moving between different power modes. We also talked directly with AMD to find out its then current stance on the results, backing up our claims on the scheduler and presented a better outlook for gaming going forward. When AMD wanted to test a new custom Windows 10 power profile to help improve performance in some cases, we took part in that too. In late March we saw the first gaming performance update occur courtesy of Ashes of the Singularity: Escalation where an engine update to utilize more threads resulted in as much as 31% average frame increase.

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As a part of that dissection of the Windows 10 scheduler story, we also discovered interesting data about the CCX construction and how the two modules on the 1800X communicated. The result was significantly longer thread to thread latencies than we had seen in any platform before and it was because of the fabric implementation that AMD integrated with the Zen architecture.

This has led me down another hole recently, wondering if we could further compartmentalize the gaming performance of the Ryzen processors using memory latency. As I showed in my Ryzen 5 review, memory frequency and throughput directly correlates to gaming performance improvements, in the order of 14% in some cases. But what about looking solely at memory latency alone?

Continue reading our analysis of memory latency, 1080p gaming, and how it impacts Ryzen!!

Author:
Subject: Processors
Manufacturer: AMD

AMD Ryzen 7 Processor Specifications

It’s finally here and its finally time to talk about. The AMD Ryzen processor is being released onto the world and based on the buildup of excitement over the last week or so since pre-orders began, details on just how Ryzen performs relative to Intel’s mainstream and enthusiast processors are a hot commodity. While leaks have been surfacing for months and details seem to be streaming out from those not bound to the same restrictions we have been, I think you are going to find our analysis of the Ryzen 7 1800X processor to be quite interesting and maybe a little different as well.

Honestly, there isn’t much that has been left to the imagination about Ryzen, its chipsets, pricing, etc. with the slow trickle of information that AMD has been sending out since before CES in January. We know about the specifications, we know about the architecture, we know about the positioning; and while I will definitely recap most of that information here, the real focus is going to be on raw numbers. Benchmarks are what we are targeting with today’s story.

Let’s dive right in.

The Zen Architecture – Foundation for Ryzen

Actually, as it turns out, in typical Josh Walrath fashion, he wrote too much about the AMD Zen architecture to fit into this page. So, instead, you'll find his complete analysis of AMD's new baby right here: AMD Zen Architecture Overview: Focus on Ryzen

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AMD Ryzen 7 Processor Specifications

Though we have already detailed the most important specifications for the new AMD Ryzen processors when the preorders went live, its worth touching on them again and reemphasizing the important ones.

  Ryzen 7 1800X Ryzen 7 1700X Ryzen 7 1700 Core i7-6900K Core i7-6800K Core i7-7700K Core i5-7600K Core i7-6700K
Architecture Zen Zen Zen Broadwell-E Broadwell-E Kaby Lake Kaby Lake Skylake
Process Tech 14nm 14nm 14nm 14nm 14nm 14nm+ 14nm+ 14nm
Cores/Threads 8/16 8/16 8/16 8/16 6/12 4/8 4/4 4/8
Base Clock 3.6 GHz 3.4 GHz 3.0 GHz 3.2 GHz 3.4 GHz 4.2 GHz 3.8 GHz 4.0 GHz
Turbo/Boost Clock 4.0 GHz 3.8  GHz 3.7 GHz 3.7 GHz 3.6 GHz 4.5 GHz 4.2 GHz 4.2 GHz
Cache 20MB 20MB 20MB 20MB 15MB 8MB 8MB 8MB
Memory Support DDR4-2400
Dual Channel
DDR4-2400
Dual Channel
DDR4-2400
Dual Channel
DDR4-2400
Quad Channel
DDR4-2400
Quad Channel
DDR4-2400
Dual Channel
DDR4-2400
Dual Channel
DDR4-2400
Dual Channel
TDP 95 watts 95 watts 65 watts 140 watts 140 watts 91 watts 91 watts 91 watts
Price $499 $399 $329 $1050 $450 $350 $239 $309

All three of the currently announced Ryzen processors are 8-core, 16-thread designs, matching the Core i7-6900K from Intel in that regard. Though Intel does have a 10-core part branded for consumers, it comes in at a significantly higher price point (over $1500 still). The clock speeds of Ryzen are competitive with the Broadwell-E platform options though are clearly behind the curve when it comes the clock capabilities of Kaby Lake and Skylake. With admittedly lower IPC than Kaby Lake, Zen will struggle in any purely single threaded workload with as much as 500 MHz deficit in clock rate.

One interesting deviation from Intel's designs that Ryzen gets is a more granular boost capability. AMD Ryzen CPUs will be able move between processor states in 25 MHz increments while Intel is currently limited to 100 MHz. If implemented correctly and effectively through SenseMI, this allows Ryzen to get 25-75 MHz of additional performance in a scenario where it was too thermally constrainted to hit the next 100 MHz step. 

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XFR (Extended Frequency Range), supported on the Ryzen 7 1800X and 1700X (hence the "X"), "lifts the maximum Precision Boost frequency beyond ordinary limits in the presence of premium systems and processor cooling." The story goes, that if you have better than average cooling, the 1800X will be able to scale up to 4.1 GHz in some instances for some undetermined amount of time. The better the cooling, the longer it can operate in XFR. While this was originally pitched to us as a game-changing feature that bring extreme advantages to water cooling enthusiasts, it seems it was scaled back for the initial release. Only getting 100 MHz performance increase, in the best case result, seems a bit more like technology for technology's sake rather than offering new capabilities for consumers.

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Ryzen integrates a dual channel DDR4 memory controller with speeds up to 2400 MHz, matching what Intel can do on Kaby Lake. Broadwell-E has the advantage with a quad-channel controller but how useful that ends of being will be interesting to see as we step through our performance testing.

One area of interest is the TDP ratings. AMD and Intel have very different views on how this is calculated. Intel has made this the maximum power draw of the processor while AMD sees it as a target for thermal dissipation over time. This means that under stock settings the Core i7-7700K will not draw more than 91 watts and the Core i7-6900K will not draw more than 140 watts. And in our testing, they are well under those ratings most of the time, whenever AVX code is not being operated. AMD’s 95-watt rating on the Ryzen 1800X though will very often be exceed, and our power testing proves that out. The logic is that a cooler with a 95-watt rating and the behavior of thermal propagation give the cooling system time to catch up. (Interestingly, this is the philosophy Intel has taken with its Kaby Lake mobile processors.)

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Obviously the most important line here for many of you is the price. The Core i7-6900K is the lowest priced 8C/16T option from Intel for consumers at $1050. The Ryzen R7 1800X has a sticker price less than half of that, at $499. The R7 1700X vs Core i7-6800K match is interesting as well, where the AMD CPU will sell for $399 versus $450 for the 6800K. However, the 6800K only has 6-cores and 12-threads, giving the Ryzen part an instead 25% boost in multi-threaded performance. The 7700K and R7 1700 battle will be interesting as well, with a 4-core difference in capability and a $30 price advantage to AMD.

Continue reading our review of the new AMD Ryzen 7 1800X processor!!