Testing The World’s Best APUs: Desktop AMD Ryzen 4750G, 4650G and 4350G

Conclusion

Having integrated graphics in a desktop processor saves the need for a discrete GPU when a screen output is needed. Having that as a fallback is always handy, however the question as to whether anyone needs anything more than that is an important paradigm to explore.

In mobile platforms, having integrated graphics is absolutely important to keeping overall power low based on the various synergies that are made when both CPU and GPU are built on the same piece of silicon. Mobile platforms can also take advantage of high-bandwidth low power memory, unlocking a lot of performance.

Consoles are basically big mobile processors, bridging the gap between mobile and desktop by having desktop-class performance and die sizes, but still using the mobile philosophy of high bandwidth and low power. Consoles also benefit from having a heavily optimized driver stack and constant hardware capabilities over the lifetime, enabling developers to get the most out of what is available.

On the desktop is where it gets messy. Desktop platforms by design are limited to DDR memory, which is higher power and lower bandwidth, but enables a lot more customization. It doesn’t take much for a low level discrete card ($100-150+) to surpass the integrated graphics, but that $100 level means that discrete solutions below this price are more for function than performance.

With integrated graphics on the desktop, there is less opportunity for users to customize – the moment you put in a discrete graphics card, the extra money, die size, and power spent for the integrated graphics is suddenly worth very little, except for times when debugging without a discrete card is needed. However, integrated graphics does enable smaller form factors.

Every desktop processor on the market today with integrated graphics is the mobile version repackaged with slower DDR memory. If we’re ever going to bridge the gap between a desktop integrated processor and a console, or beyond, then there has to be a suitable system paradigm. A processor with more graphics power would be bigger (increase in die area), but also more memory bandwidth would need to be added. Recently we’ve seen the older Xbox One S processors be repackaged for desktop use (that’s the A9-9820 in our tests, review coming soon), with a good die size for an integrated graphics solution. Even with slower DDR3 memory, the integrated graphics is relatively good for such an old processor. If we had something more modern, with 4-8 channels of DDR4 memory (or an onboard cache / separate cache chip), then integrated graphics could go above and beyond current solutions.

But is there a market for it, on the desktop?

For AMD, repackaging its laptop CPUs is relatively easy. As long as the memory controllers work, the only thing holding it back would be good demand for the processors as laptop processors rather than desktop models (and is in fact the situation AMD currently finds itself in).  By making the Ryzen R4000 desktop series available to OEMs only for prebuilt systems, it allows AMD to focus its limited supply on the notebook segment while also supplying specific desktop customers that can more accurately track their own customer demands, rather than have to supply a full ecosystem of individual end-users.  The silicon that goes into R4000 desktop APUs might also be dies that don’t quite meet the stricter voltage/power demands of the notebook, but it helps that the silicon can scale to desktop power levels.

For Intel, there has been no inclination for mobile Tiger Lake processors to come to the desktop. The situation as we understand it is a bit more dire regarding supply of the laptop variants: according to a recent report, Intel cannot fulfil the orders from the major OEMs. We have no worries that the silicon can scale to desktop power levels (we see 51 W spikes on the 28 W mode), however Intel is also set to bring an 8-core 45 W version of Tiger Lake to market next year, which might be more desktop suitable.

But back to the products at hand – how exactly have they performed?

Desktop APU vs Desktop APU

Throughout the tests, there’s admittedly not much to choose between the three AMD Ryzen 4000 processors. In a few tests the reduced core count of the Ryzen 3 pegs the performance, however the Ryzen 5 is often just a gnats wing away from the Ryzen 7. In pretty much every case, the new Ryzen 4000 performance surpasses the Ryzen 3000 APUs, although not often by much – this is partly down to how AMD has reordered from Vega11 to Vega8, choosing a different graphics combination for die area and frequency. If we compare to Intel’s best desktop integrated graphics solution, the Core i5-5775C, because it is relatively old now, AMD forges on ahead to lands anew.

Integrated vs Integrated

When comparing absolute integrated graphics performance between the desktop R4000 and mobile solutions, the Ryzen 4000 APUs appear to be ahead at lower resolution/fidelity testing, while Tiger Lake can get the upper hand at the higher resolutions. In some benchmarks Tiger Lake pulls ahead by a good margin, whereas in others it can be behind even the Ryzen 3, or sitting between the three APUs.

When comparing best against best, the differences can swing from a +55% performance to AMD (Civilization 6) to a +40% performance to Tiger Lake (Final Fantasy 14). Overall, at the lower settings, AMD has a +5.5% advantage. At the higher resolution and quality settings, Intel has a +5.8% advantage.

Integrated vs Discrete

This is where it gets a little bit tricky – discrete cards have a lot more memory bandwidth, and so can enable better graphics at times where memory bandwidth is important. If we compare the 4750G against the 2600+GT1030 for example, the integrated graphics wins in 7 titles, but when it loses, the discrete graphics card wins by 30-50% (Final Fantasy 14), especially in low quality settings. In high quality settings, often the reverse is true, and the integrated graphics wins by up to +61% (F1 2019).

When we move up to the GTX 950, which is a more expensive card, everything falls in favor of the GTX 950.

Overall

It’s clear from our data that AMD’s integrated graphics solutions aren’t great for specific games – Final Fantasy 14 being the key one. However, when pairing this level of integrated graphics with this level of CPU compute, titles like Civilization 6 and F1 2019 shine.

While AMD has not launched Ryzen 4000 APUs for end-users on the desktop, there are a number of segments with their fingers crossed that the next generation of APUs will be coming in desktop packaging. There have been rumors as to what that could be (Zen 3 + Vega, or Zen 3 + RDNA2), and when, and for how much. We look forward to whether AMD plan to push the integrated graphics market further, especially in light of recent launches.