Now that Sony has finally unveiled the specs for the PlayStation 5, we can do what we’ve been wanting to do for a while and examine overall performance against the Xbox Series X. First impressions count for a lot in the console world, and Microsoft has been quite aggressive in terms of product design.
Let’s kick off by taking a look at what we know about each platform and the salient characteristics of each.
We won’t be discussing teraflops today, because they’re a wretched way to measure performance. A GPU’s teraflops rating is derived from a mathematical formula that no card can actually achieve. It can make some sense to discuss teraflops when we’re talking about HPC computing, but GPUs are not simply a collection of cores. Other critical aspects of design, including memory bandwidth, cache size and distribution, clock speed, bus width, and pixel/texel fill rates have huge impacts on how well a GPU can game, but they don’t affect its theoretical FLOPS rating at all.
Here’s our advice: When companies talk about teraflops, treat that as equivalent to the way CPU cores or clock speeds used to be the center of attention. Remember that MHz alone has never been an accurate way to capture the performance of two processors. Having tons of weak CPU cores isn’t beneficial if they can’t get something single-threaded done. Here, Sony and Microsoft have decided to emphasize teraflops.
We will acknowledge that in this specific case, with two seemingly identical GPU implementations (as far as supported features and hardware design), and two CPUs very close in speed, teraflops is a slightly better metric than it normally would be. Then again, if Mark Cerny was telling the truth in the briefing the other day, the PS5 has tricks to close the gap between itself and the Xbox Series X. Ultimately, this is the exception that proves the typical rule — don’t treat teraflops as the be-all, end-all of performance metrics.
Xbox Series X: Core Clocks, Backwards Compatibility Locked In
The Xbox Series X offers static core clocks and constant frequencies on both CPU and GPU. The CPU runs in two modes — either with SMT disabled, with a static clock of 3.8GHz, or with SMT enabled and a static clock of 3.6GHz. Single-threaded performance is claimed to be 4x higher than the Xbox One X.
The system supports ECC data correction and fields a very robust GPU. Unless AMD changed the number of cores per compute unit (unlikely — it’s been 64 for years), we can expect the GPU to 3,328 cores. This is wider than any Navi-class GPU AMD has yet brought to market and it’s part of what puts the Xbox Series X on a comparable technical footing with upper-midrange gaming PCs.
The XSX offers two conceptual “pools” of memory, though the actual system still uses a unified memory model. There’s 10GB of GPU-optimal RAM with 560GB/s of bandwidth and 6GB of “CPU optimal” RAM at 360GB/s of bandwidth. The performance implications are unclear because it’s possible for the GPU to put data in the “CPU optimal” block and vice-versa. The GPU is clocked 1.56x faster than the Xbox One X, while the CPU is clocked 1.78x faster without SMT and 1.69x faster with it. The claim of a 4x improvement in single-threaded performance is plausible if you consider the combined impact of architecture, clock speed, and the fact that Zen 2 supports 256-bit AVX/AVX2 operations, while Jaguar was limited to 128-bit AVX and didn’t support AVX2 at all.
Microsoft is claiming to have done a lot of custom work around the Xbox Series X’s storage subsystem, with a new DirectX extension — DirectStorage. DirectStorage delivers up to 100GB of game assets as “extended memory” with guaranteed performance of up to 2.4GB/s. Microsoft claims to have optimized DirectStorage specifically for game asset delivery. The Xbox Series X also supports instant resume from multiple games. You can pause a title and switch to a different game. Eurogamer reports the feature supports a minimum of three titles and takes roughly 6.5 seconds to swap between them.
Microsoft is also emphasizing seamless backward compatibility as a major feature for the Xbox Series X. The Series X can run the entire Xbox One game library natively and will continue to support emulating Xbox and Xbox 360 games.
Sony: Flexible Clocks, Fast GPU, Faster Storage
The PlayStation 5 shares a lot of DNA with the Xbox Series X, but the implementations are quite different. Where Microsoft emphasizes steady clocks, the PlayStation 5 has boost capabilities that control system performance by monitoring overall power usage across the SoC rather than focusing on temperature. From the way Mark Cerny talks about the platform, it sounds as though it implements a version of AVFS — Adaptive Voltage and Frequency Scaling. It definitely makes use of SmartShift, a recent technology AMD announced as part of the Ryzen Mobile 4000 debut.
The PlayStation 5 runs at “up to” 3.5GHz but doesn’t boost based on temperature. Instead, it boosts based on power consumption level. The net effect is to ensure every PS5 runs at the same speed. The CPU clock can be assumed to be somewhat lower than 3.5GHz, but the GPU clock is very high — 2.23GHz, well above anything we’ve seen AMD ship before. If this can be deployed in next-generation Navi GPUs, the gains could be significant indeed. According to Sony, it’s actually more efficient to use a smaller GPU with fewer cores than a slower, wider design. The feature set on the GPU, including capabilities like ray tracing, appear to be analogous with what the Xbox Series X is going to offer.
Render by LetsGoDigital
Storage performance is a major focus for the PlayStation 5. If it delivers the bandwidth it promises, it could leave the Xbox Series X in the dust. With a 5.5GB/s raw data rate and 8-9GB/s compressed, the PlayStation 5’s storage offers roughly the same amount of bandwidth as a single-channel DDR-400 RAM channel, circa 2004. While latency would obviously be much higher, that’s an impressive achievement in its own right. Sony claims this will greatly improve gaming by offering essentially zero load times. The onboard SSD uses PCIe 4.0 and offers (theoretically) 2x the performance of the Xbox Series X. Whether Sony can take advantage of this to specifically improve games for its platform is an open question.
Strengths and Weaknesses
Based on specs alone, Microsoft should have the edge over the PlayStation 5, but there are still some questions to be answered. The Xbox Series X uses unified memory, but it still splits that 16GB into two conceptual pools. 10GB of RAM runs at 560GB/s, while the remaining 6GB offer 336GB/s. The former is intended for GPU use, while the latter is for the CPU. That’s odd, and developers often don’t like odd things. There’s also the fact that Microsoft is using a proprietary storage solution for the Xbox Series X. We don’t know pricing on the cards yet, but they aren’t likely to be cheap.
Sony seems to have an advantage as far as sustained storage speed and ease of upgrade, but it’s not clear how much these benefits will translate into gaming advantages. Microsoft has talked up some AI capabilities of the Xbox Series X based on its ability to handle 4-bit and 8-bit integers. It’s not clear if Sony’s RDNA2 GPU has a similar ability.
Sony’s claims about the PS5’s more nimble GPU are interesting, but they need to be demonstrated in head-to-head comparisons. Sony has the not-inconsiderable advantage of being the market leader in this space and has a much larger install base to work with. Microsoft, meanwhile, will be trying to lure gamers away.
Based on raw specs, I’d give the lead to Microsoft — but it’s an open question how much that matters. If you look back at the history of game consoles, the system with the best hardware doesn’t always win. Microsoft’s Xbox One X has been the most powerful console you could buy for several years now, and yet the estimated 2:1 gap between Microsoft and Sony hasn’t budged.
Finally, we don’t know price. That’s the most significant part of the entire affair, and there have been rumors Sony was struggling to bring the PlayStation 5 in at budget. Right now, I’d say Microsoft has the faster system and the larger online ecosystem as far as supporting capabilities such as console-PC streaming, Xbox Game Pass, and xCloud. The PS5 has a really interesting storage solution, a huge install base, and an easier and likely less expensive way to expand storage.
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