Xbox Series X | S final tech specs revealed – Series S RAM speed could affect backward compatibility

As part of today’s Xbox Series X | S release date and pricing announcement, Microsoft have released a little slide detailing the final tech specs of the two consoles, showing the relative teraFLOP-iness of the two consoles, and confirming a few details about CPU speed and RAM size. What’s surprising is that, since the start of this year, the Xbox Series X has apparently become just that little bit more powerful.

But first the Xbox Series S. The console has a lot in common with the Xbox Series X, with an 8-Core Zen 2 CPU, but this is clocked at 3.6Ghz or 3.4Ghz with SMT, putting it 200Mhz shy of the bigger console. That’s paired with a 20 CU RDNA 2 GPU at 1.565Ghz, which produces 4 TFLOPS of power. There’s also 10GB of GDDR6 RAM, with 8GB at 224GB/s (roughly half the speed of the Series X) and 2GB at a much, much lower 56GB/s on the Series S to cater for system processes. The 512GB SSD is an exact match for the speed of the Series X, and the console will take the same 1TB expansion card SSDs.


All of that is roughly what was expected, though it’s clear they’re scrimping a little on CPU speed. The main surprise is the speed of the RAM, which is dramatically slower, though a typical compromise made in GPU design for lower specced parts.

Update: As noted on Twitter by GigaBoots, the Series S has less of its speedier RAM (8GB) than the Xbox One X makes available to developers (9GB), and it also runs at 224GB/s compared to the One X’s 326GB/s. The implication is that for backward compatibility to Xbox One titles, the Series S would not be able to run games in the One X mode, and would instead step back to original Xbox One resolutions up to 1080p. The Series S target of 1440p could also be the target it adopts for Xbox 360 and Xbox One backward compatibility.

But on to the Xbox Series X, where all of the specs match up exactly to the March hardware reveal… except one. The stated GPU Power is now at 12.15TFLOPS instead of 12TFLOPS. That’s despite featuring the same 52CU design and having the same 1.825Ghz clock speed as announced way back when. All we can assume is that some kind of refinement of the GPU design on AMD’s part has allowed them to eke out just a smidgeon, and almost unnoticeable amount of extra power.

Here’s the full table:

Xbox Series X Xbox Series S
CPU 8-Core Zen 2 @ 3.8Ghz / 3.6Ghz w/ SMT 8–Core Zen 2 @ 3.6Ghz / 3.4Ghz w/ SMT
GPU RDNA 2 GPU – 52 CUs @ 1.825 GHz RDNA 2 – 20 CUs @ 1.565 GHz
Memory 16 GB GDDR6 10 GB GDDR6
Memory Bandwidth 10GB @ 560 GB/s, 6GB @ 336 GB/s 8GB @ 224 GB/s, 2GB @ 56 GB/s
Performance Target 4K @ 60 FPS, Up to 120 FPS 1440p @ 60 FPS, Up to 120 FPS
Internal Storage 1 TB PCIe Gen 4 NVME SSD 512 GB PCIe Gen 4 NVME SSD
I/O Throughput 2.4 GB/s (Raw), 4.8 GB/s (Compressed) 2.4 GB/s (Raw), 4.8 GB/s (Compressed)
Expandable Storage 1 TB NVME Expansion Card 1 TB NVME Expansion Card
Optical Drive 4K UHD Blu-Ray Drive Digital Only
Video Output HDMI 2.1 – Up to 4K at 120Hz, 8K, VRR HDMI 2.1 – Up to 4K at 120Hz, 8K, VRR
Backward Compatibility Xbox One, Xbox 360, Xbox Xbox One, Xbox 360, Xbox
Availability 10th November 2020 10th November 2020
Price $499 / £449 / €499 $299 / £249 / €299

Source: Xbox

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  1. So the GPU is 3 times as fast on the X, the CPU is near enough the same, and the memory is 4 times as fast (on average – only 2.5 times as fast if you only look at the faster 10 or 8 GB)

    So overall, 10 times as powerful? So the PS5 digital edition could be about 10 times as powerful for £100 more. We’ll be generous and say MS are right on the X being the most powerful thing ever, and say the PS5 might be 8 times more powerful than the S. So enjoy your games at 720p60 ;) (Yeah, I know that’s not quite how it’ll end up)

    Sony are going to be pushing the digital edition heavily, aren’t they? 8 times as powerful for just £100 more. If they can afford it and make it just £50 more, they’d slaughter MS again. Even at £349, they’re going to do well.

    How much is the S going to hold games back on the X though? If they’ve got to run on both, and it’s that much less power?

    • You’re overthinking the RAM thing. On Series X, devs get 13.5GB. All the faster 10GB is there for the GPU, with 3.5GB slower for game engine and whatever that doesn’t need to be so fast. It’s all still very fast. One Series S, it’s like the slower RAM is purely for the system (it’s still double the speed of most DDR4 in a).

      It’s all a balancing act, a smaller GPU can’t make the best use of a vast pool of ultra-fast RAM, so hopefully MS have found a good compromise for the system’s longevity. The CPU power should ensure that the actual game logic runs just as well on both consoles, SSD is just as fast for loading, so it’s just the GPU.

      • It’s all going to be an interesting balancing act, sure.

        All 3 machines are going to be impressive to some degree. The X, S and PS5.

        The S might be a bit disappointing, depending on how much attention you pay to what MS are saying. Not convinced it’s going to get much about 1080p60 or 1440p30. But that’s fine if you’ve not got a 4K TV.

        The X vs PS5 thing will be the really interesting battle. The only real difference is the X has more GPU CUs, but they’re a lot slower than the PS5 ones. There’s plenty of convincing arguments why the PS5 might still come out on top there. But those arguments seem to be based on current games that have other hardware limits.

        We’ll end up with cross-platform games performing just as well on the X and PS5, with a lower resolution on the S. And you can’t really compare any exclusives between the PS5 and X. And not just because the X won’t have any for a while ;)

        All 3 are going to be great machines though. Just can’t see a real reason for the X over the PS5. But an S as a second machine in a year or 2? Quite possibly.

      • Also bear in mind that the S could look even more attractive in a few years once it’s cheaper and Project X Cloud is more established. And that would get around some of the hardware limitations too.
        It’s also perfect for someone who just wants a new console but is happy to wait for the inevitable ‘Pro’ versions that will come along in a few years time.

  2. That’s a bit odd if the Series S has less and slower memory than the One X. Although that tweet about it has been deleted, seemingly because some X Box fans are arseholes and didn’t like it being pointed out.

    So One X games work on the original One, the Series S, One X, and Series X in order of how well they’ll perform?

    And PS4 games will work at least as well as on the Pro on both the PS5s? (Or possibly better, but we don’t know much about the BC yet, other than that it works, probably, and Sony are at least being honest about the fact that it might not work in some rare cases)

    I’m sure Sony will be pointing that out.

  3. Silly question… how do you do backwards compatibility without a disc drive?

    • Digitally. There’s a lot of 360 and original Xbox games on the digital storefront, and obviously all the Xbox One games as well. Everything in Xbox Game Pass will be compatible as well.

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