Tuesday, September 24, 2019

RX 5700 XT and RX 5700 Review: Navi makes a solid impression

The past two or three years have been a mixed bag for AMD's graphics wing, unlike its CPU division which has been on a role with Ryzen. The last time it had a major successful launch was three years ago, with Polaris GPUs. The pricey and power hungry Vega, while working as a stopgap solution, never quite took the fight to Nvdia's camp. And considering the 7nm Radeon VII was never meant for pure gaming, AMD had to bring something to table that could not only disrupt Nvidia's Turing line-up but pave the way for future Radeon products.

That something came in the form of 7nm Navi GPU, launched back in July along with 3rd generation Ryzen processors. Apart from bringing all the benefits of a process-shrink, Navi features a new and improved RDNA (Radeon DNA) graphic architecture and replaces GCN (Graphics Core Next) based Vega within AMD's product stack.

While RDNA isn't a complete architectural overhaul, many of its aspects have new elements introduced in almost every level. With RDNA, AMD's focus is on improved single-threaded performance and better utilization of fixed-function hardware. That means RDNA is better suited for gaming whereas GCN was better at handling complex HPC type workloads - part of the reason why AMD still keeps the GCN based Radeon 7 around.

Here are some key highlights of RDNA/Navi:
Click to enlarge
The new 7nm process -  Navi is smaller and more efficient with a 2.3X performance per area advantage over its predecessor. Compared to the 14nm Vega, AMD claims a 14% higher performance at same power envelope and a healthy 25% boost clock-for-clock. The increased transistor density also enables higher clock-speed which brings the RX 5700 series in a level-playing field with competing Nvidia cards.

Redesigned Compute Unit (CU) - AMD has doubled the amount of Scalar Units and Schedulers within Navi's CUs, resulting in twice the instruction throughput. Navi's RDNA design now has an adaptive Wave32/Wave64 mode and unlike GCN, each RDNA SIMD can now decode and issue new instruction every cycle which is achieved through executing Wave32 data-flow on SIMD32. Also, two CUs now work as a Work Group Processor (WGP) to better allocate shared resources.

Multilevel Cache Hierarchy - Navi GPU features a more defined and efficient cache subsystem with 512KB of intermediate L1 graphics cache which now handles all data requests from shader arrays and routes the necessary ones to a globally shared L2 (4MB). The L0 to ALU load bandwidth has been doubled speed-up things. Another significant change is the implementation Delta Color Compression (DCC) across the rendering pipeline to increase the effective memory bandwidth. all these improvements work toward reducing latency and power draw.

Navi's new media Engine supports hardware acceleration for faster 8K encoding/decoding of VP9/HEVC videos. It also keeps Vega's Asynchronous Compute engines (ACE) and Primitive shaders, with the later in a more functional form with the added flexibility of being compiler controlled.

Click to enlarge
AMD's latest offering comes in two flavors - RX 5700 XT and RX 5700, both equipped with 8GB GDDR6 memory and PCIe 4.0 support. The "XT" is based on a fully enabled Navi 10 GPU with a total of 2560 stream processor/shader units spread around 40 CUs. The "non-XT" gets a trimmed down version of the same silicon at 2304 stream processors.

Comparison table vs. AMD Radeons cards:

Graphics card
Radeon VII
RX 5700 XT
RX Vega64
RX 580
GPU
Vega 20
Navi 10
Vega 10
Polaris 20
Process
7nm TSMC
7nm TSMC
14nm GloFo
14nm GloFo
Shader cores
3840
2560
4096
2304
Base clock
1400 MHz
1605 MHz
1247 MHz
1257 MHz
Boost clock
1750 MHz
1905 MHz
1546 MHz
1340 MHz
Memory clock
1000 MHz
1750 MHz
953 MHz
2000 MHz
Memory Bus
4096-bit
256-bit
2048-bit
256-bit
Memory Bandwidth
1 TB/s
448GB/s
484GB/s
256GB/s
V-RAM
16GB HBM2
8GB GDDR6
8GB HBM2
8GB GDDR5
ROPs
64
64
64
32
Texture Units
240
160
256
144
Power(TDP)
300w
225w
295w
185w
Price
60,000
35,000
30,000
16,000

RX 5700 XT, as you see, has the fastest clocks among all recnt Radeon GPUs and despite having a narrower memory interface and ~40% lower Shader cores, it outperforms the big Vega64 by at least 15%. We've decided not to include AMD's so-called "Game clock" ratings which sits roughly between the base-clock and boost-clock. In the light of Ryzen's recent clock speed controversies, we don't really feel we need a new third rating to further complicate things!

comparison table vs. Nvidia RTX cards:

Graphics card
RTX 2070 Super
RX 5700 XT
RTX 2060 Super
RX 5700
RTX 2060
GPU
TU104/Turing
Navi 10
TU106/Turing
Navi 10
TU106/Turing
Process
12nm TSMC
7nm TSMC
12nm TSMC
7nm TSMC
12nm TSMC
Shader cores
2560
2560
2176
2304
1920
Base clock
1605 MHz
1605 MHz
1470 MHz
1465 MHz
1365 MHz
Boost clock
1770 MHz
1905 MHz
1650 MHz
1725 MHz
1680 MHz
Memory clock
1750 MHz
1750 MHz
1750 MHz
1750 MHz
1750 MHz
Memory Bus
256-bit
256-bit
256-bit
256-bit
192-bit
Memory Bandwidth
448GB/s
448GB/s
448GB/s
448GB/s
336GB/s
V-RAM
8GB GDDR6
8GB GDDR6
8GB GDDR6
8GB GDDR6
6GB GDDR6
ROPs
64
64
64
64
48
Texture Units
160
160
136
144
120
Power(TDP)
215w
225w
175w
185w
160w
Price
45,000
35,000
34,000
31,000
28,000

After some preemptive repricing and repositioning of their respective product stacks, this is how competing AMD and Nvidia's competing graphics cards stand at the moment. With the introduction of Nvidia's super cards, the production of RTX 2070 is now discontinued and as such we haven't included it in the list. The specs are from reference editions, or founder's edition in case of Nvidia cards and the prices are taken from leading Indian e-tailers.

In terms of clock-speed, number of shader cores and memory bandwidth and capacity, the specs of these upper-mid range contenders closely match each other, except the 192-bit, 6GB RTX 2060. This is something we've been missing for last couple of years thanks to AMD's big-die GPUs with HBM, like Vega and Fiji. With a more streamlined architecture and conventional GDDR6, Navi seems to have restored much of the disparities. But does that reflect in the performance? Let's find out.



Performance Analysis: as always, we've been through tons of benchmark data from some of the biggest names in tech-media and both RX 5700 XT and RX 5700 deliver stellar gaming performances. Most reviewers found these cards to be very competitive in terms of price, performance and power consumption and ideal for 1440p gaming. Here some numbers to prove that -

Performance comparison table - all games average percentage:

AnandTech:

RX 5700 XT
RX 5700
Vs. RTX 2070 Super – 5% slower
Vs. RTX 2060 – 12% faster
Vs. RTX 2060 Super – 11% faster


Tom's Hardware:

RX 5700 XT
RX 5700
Vs. RTX 2070 Super – 7% slower
Vs. RTX 2060 – 11% faster
Vs. RTX 2060 Super – 10% faster
Vs. RX Veag64 – 15% faster


TechPowerUp:

RX 5700 XT
RX 5700

Vs. RTX 2070 Super – 12% slower
Vs. RTX 2060 – 5% faster


Vs. RTX 2060 Super – 5% faster

Vs. RTX 2060 Super – 8% slower

Vs. RX Veag64 – 16% faster



TechSpot:

RX 5700 XT
RX 5700

Vs. RTX 2070 Super – 2% slower
Vs. RTX 2060 – 8% faster


Vs. RTX 2060 Super – 13% faster

Vs. RTX 2060 Super – 1% faster

Vs. RX Veag64 – 15% faster



Don't forget that these are results from different review sites and thus not inter-comparable. The deviations in the results are due to the difference in used hardware and choice of tested games. While we would very much like to see platform agnostic game developing, unfortunately, that's not the case! In reality, most games are better optimized for one GPU design or other. And we're OK with that as long as things are kept playable across the range.

As things stand now, Radeons do well in Battlefield 1, Battlefield 5, far Cry 5, Strange Brigade, Tom Clancy's The division, Wolfenstein 2, F1 2018, Deus Ex: Mankind Divided and Middle-earth: Shadow of War. Games such as Ashes of Singularity: Escalation, Hitman 2, Resident Evil 2, GTA 5, Assassin's Creed Odyssey and Metro:Exodus provide a somewhat middle ground while Forza Horizon 4, Destiny 2, Rise of the Tomb Raider, Final Fantasy XV, Tom Clancy's Rainbow Six Siege, Fortnite, Monster Hunter: World typically favors team GeeForce. 

Having said that, the performance displayed by the Navi duo doesn't take much interpretation. The RX 5700 XT, which was originally supposed to go against RTX 2070, don't have much competition at its price point as the faster RTX 2070 Super is also ~INR.10K costlier. The 5-8% performance increment doesn't warrant a 25% price hike in our book. At around 10% faster, the XT is well beyond the reach of RTX 2060 Super, all the while costing just a fraction more. So unless you find a great deal on the outgoing RTX 2070, this is the card to have in the 30K-35K range. 

RX 5700 is in a more curious position, at least price wise. With an INR.30K price tag, it's not significantly cheaper than its faster sibling which means it lacks the usually excellent price/performance ratio associated with AMD's second fiddle GPU's (think HD6850, R9 390, RX 570, RX Vega56). It's still delivers 10% more frame rates than RTX 2060 -a card that desperately needs some price reduction to justify its substandard showing. Speaking of which, we can't help thinking that a slight price reduction won't hurt the RX 5700 either. In fact, at a sub-30K price-line, the lil' Navi can be an automatic choice for those planning an upgrade from GTX 970, GTX 1060 6GB or Vega56.

Power consumption is metric that we always keep a keen eye on; after all, power isn't cheap in India, nor is it going to be! Thankfully, it's not going to be a factor while choosing RX 5700 series cards. AMD has covered quite some grounds in making Navi much more efficient than its predecessors. while it's still not "Nvidia good", the energy consumption is in-line of a 2019 component and nothing that a well-built 650W power supply could not handle. RX 5700 is more efficient between the two, thanks to its lower clock-speed but both cards demonstrate excellent power/performance ratio.


Conclusion and verdict: Finally, there are two things that may stop you from grabbing one of these. The first is the fact that Nvidia's offering feature Realtime Ray Tracing and AMD's don't! During our RTX 2060 review, we discussed the matter in-depth. In one hand, it's undeniable that Ray Tracing can add a great deal of realism and immersion into a modern tittle; on the other, it is a question of how much of a performance hit are you willing to accept for that! Also there is the matter of the tech being relatively new and not many AAA tittles supporting the tech at this moment. That may very well change in the future but for now think of it this way - AMD gives you more FPS but Nvidia gives you better looking (and relatively lower) FPS at the same price!

That choice is much simpler in the value-sensitive mid range segments where a gamer on budget goes by the motto of "performance over eye-candy". But when you're splurging north of 30K on a single graphics card, the question of visual perfection becomes more relevant. If you ask me, Realtime Ray Tracing is yet to become a must have feature but in the end it's up-to you to decide.

Availability could be yet another deterrent. A limited stock and poor distribution could trigger the prices of these cards on a upward spiral, -a scenario we Indian consumers are very familiar with! AMD needs to make sure that doesn't happen by working very closely with its channel partners and importers. AMD's quoted price must stick and reflect on the market for our recommendations to stay valid. As always, we'll keep an eye over the situation.

So here we are, time for our verdict! With excellent performance and very competitive pricing, We have no reservation recommending the Radeon RX 5700 XT and RX 5700 for high-resolution gaming. In particular, The Radeon RX 5700 XT is the best upper-mid range graphics card for the money. 

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