AMD Radeon RX 5700 and RX 5700 XT Review
There are some serious changes going on with AMD in recent times.
Famously we here at OC3D cut our overclocking teeth on AMD hardware back in the Thunderbird and Barton days. It doesn’t take much imagination to know that the performance of their hardware for a long time was something that we felt sad about. Not just with our work heads on, but also on a personal level as the enthusiasts we are. The world is a brighter place for competition between manufacturers. There are ideas being spread with some seriously clever R&D people coming up with new ways to solve incredibly complex problems, and that bleeds through the market. Additionally people intending to buy having a wider choice and usually at more competitive pricing than would appear in a monopoly. The Playstation and Xbox might be basically the same thing, much like Android or IOS phones do basically the same thing, but competition fuels creativity and everyone benefits for there being more than one option.
With the launch of the Zen architecture and Ryzen CPUs we saw our first indication that AMDs business revolution was bearing fruit. The Zen and 2nd Generation Ryzen hardware solidified that into a product which was a genuine challenger for the foundation of your gaming PC. Today with the launch of the 3rd Generation Ryzen CPUs and X570 that blossoms into something which is beginning to take the performance lead. The GPU side of AMDs business has been a little more unstable. The Vega RX series, particularly in Vega64 guise, were good, but suffered from the heat and power problems that have been a feature of Radeon’s in recent times. The Radeon VII was a significantly more well-rounded product, but had a price tag which threatened to lift it out of the reach of the mainstream who are such a large part of the AMD consumer group.
Now the CPU and motherboard side of the business has been brought screaming back to the forefront of the market it was only a matter of time before those freed resources were brought to bear on the problem of producing a graphics card which could stand shoulder to shoulder with offerings from the other side. Enter the RDNA architecture which powers the 7nm Navi GPU beating at the heart of the latest AMD Radeon cards. We know you have a lot of reading material to digest in one sitting today with this mass AMD launch, so without further ado let’s get down to what the Navi RX 5700 brings to the table.
The current mainstream AMD graphics cards are based around the Vega design. This is a 14nm process which had good performance but that very much came at a heat and efficiency price. The Navi is AMDs first implementation of their 7nm process and two comparisons show how far the Navi has come when compared to Vega. Firstly the die size. Naturally with a halved process the die has shrunk too. The Vega64, for example, was 495 mm2, whereas the Navi is a mere 251 mm2. Transistor count is similar, 12.5 billion on the Vega64 versus 10.3 billion here, whilst the TDP has dropped from 295W with the Vega to just 225W with the RX 5700 XT and 185W on the RX 5700.
If you just looked at Compute Unit and thus Stream Processor sizes you would be forgiven for thinking this Navi is a sideways step. If we just compare the RX 5700 XT and Vega64 we see the Compute Units are down to 40 from 64, and this affects the Stream Processor count down to 2560 from 4096. Even with a boost to the clock speed – up to 1905 MHz from the Vega 1546 MHz – this has an effect on the calculative abilities of the Navi RX 5700 XT with 9.75 TFLOPS instead of the 12.7 TFLOPS on the Vega. Even Texture Fill-Rate has dropped to 304 GigaTexel/s against 395 GT/s. You would be forgiven for wondering what all the fuss is about then. But that’s because we are writing this knowing how fast the RX 5700 is compared to the Vega, whilst (unless you’ve been impatient) you don’t yet.
There is one more adjustment before we move on to the architectural side of things and our all-important benchmark results. When the Vega first appeared much was made of the 2048-bit High Bandwidth Memory. The RX 5700 has reverted back to GDDR, although the latest GDDR6 specification. This must have a cost saving as well as making it easier for programmers to address by unifying it with the rest of the marketplace.
The improvements that Navi bring are just things you can lay out on a specification table though. There is much going on beneath the lid and behind the scenes.
|Radeon RX 5700 XT
|Radeon RX 5700
|Peak SP Performance
|Half Precision Performance