PlayStation 5: Storage Makes a Bigger Impact Than You Think!

The PS5 has finally launched, and if you were lucky enough to have snagged one you are living in the future. This post will largely ignore the Nintendo Switch due to it being in a league of it’s own, not in direct matching competition with the PS5 or Xbox Series X (XSX). Headline aside, this isn’t intended to be a ‘fanboy’ post. I do not intend on purchasing an XSX because I already own a gaming PC, and all first party games will have a PC version; however, the XSX appears to be a worthwhile console. As such, I will focus less on the XSX, and more on the PS5. The hardware specifications of the PS5 and the XSX are unsurprisingly similar. The last time that consoles were significantly different at an architectural level that people seemed to care about was the PS3/Xbox 360 generation (7th). Sony developed the Cell processor to power the PS3, and while it was capable of delivering awesome experiences and was a powerhouse, it was a nightmare to develop for. The following console generation (8th) saw the Xbox One and PS4 use AMD processors, which has continued into the current generation.

Starting with the 8th Generation, in my experience the only meaningful difference between the two consoles were the exclusive games, online marketplace, and social spaces. Having owned both a PS3 and Xbox 360 as well as a PS4 and Xbox One, while I enjoyed the Sony consoles more because of the games that I owned for them, the gaming experience (graphically at least) was perceptively nearly the same. The hardware was not really the focus for those consoles (for me); it was the gaming. I purchased Sony to play Kingdom Hearts, Uncharted, Metal Gear Solid, God of War, The Last of Us, and Horizon Zero Dawn. I purchased Microsoft because I wanted to play Halo, Gears, Crackdown, and Rare Replay… Given that all first party XSX games are coming to PC, and the likelihood that most other games will be cross platform, the remaining games will be PS5 exclusives. With backwards compatibility, the PS5 can play PS4 (not PS3/2/1) games, consolidating the recent Sony-only gaming experiences into a single console. With new storage hardware and mechanisms Sony has laid the foundation for better gaming experiences on the PS5, at least for me. Allow me to explain.

The previous two generations of consoles made use of the same SATA interface storage that was common among PCs since 2003. While these consoles came with spinning 2.5 inch hard drives, in some cases it was possible to replace them with 2.5 inch SSDs. Spinning drives have rotating data platters that are written to and read from by an electromagnet mounted on a pivoting arm. The disk platters must be rotated and the arm must be pivoted into a precise position to read/write data. SSDs are made of no moving parts, and consist of an array of flash memory chips allowing significantly faster data manipulation. Switching to SSD certainly increased performance for PCs, but for 7th Generation consoles it was more of a mixed bag. The Xbox 360 did not accept SSDs for onboard storage, and USB storage was limited by USB 2.0 speeds. PS3 users could use SSDs; however, the SATA II controller was a bottleneck that severely limited transfer speeds. Even with the bottleneck, SSDs are still better than the 5400 RPM spinning drives the PS3 shipped with, but at the time SSDs were significantly smaller in capacity and more expensive than they are now. Game files needed to be loaded from the HDD/SSD into the console’s RAM to be used by the CPU and GPU. Once the files were in RAM the HDD/SSD is accessed only to save data or load new data. Because of this, the performance increase gained from swapping to an SSD was only really noticeable during game installs, the initial game load, and level changes. It wasn’t mind blowing. Loading screens still existed and even the minimal performance increases varied by title depending on how the developer coded the game. PS3 owners faced a decision; do you sacrifice space for a little performance bump at a premium, or do you stick with spinning drives? The silver lining at the time was that users that didn’t want to pony up the SSD dough could upgrade to a 7200 RPM spinning drive. They were cheaper than SSDs, spacious, and gave a small performance boost due to spinning faster.

The 8th Generation comes around and the stock storage for Xbox One (XBO) and PS4 is still 2.5 inch spinning hard drives. The initial PS4 model utilized a SATA II interface with the PS4 Pro using a SATA III interface. At that time SSDs were notably less expensive, and had come a long way in terms of capacity. Swapping to an SSD seemed like a no brainer, and it absolutely reduced game load times. The site has an article that compares actual game load times before and after an SSD installation. The loading times are halved in some cases!

This performance increase is notable, but consider that even with the gains from the SSD, gamers are still looking at relatively long loading times. Why?

As stated above, the 7th and 8th generation of consoles were manufactured making use of SATA drives. An SSD being significantly faster than a spinning drive does not necessarily translate to a faster game experience for a few reasons. The PS3 and PS4 allowed for an SSD to be used, but it didn’t explicitly leverage SSD performance due to the SATA interface. SATA interfaces replaced PATA(IDE) interfaces, and are remarkably faster by comparison, but SATA was originally developed for spinning drives, not SSDs. Also, for the PS3 and initial PS4 models, a SATA II interface was used. No spinning drive will be so fast as to fully utilize the SATA II interface, but even a budget SSD can max out the connection. The storage hardware isn’t the only issue though…

The manner in which games are developed and how gaming assets are stored play a huge role in delivering a quality experience. Game developers are challenged to create a game that looks great, plays well, loads fast, works flawlessly, and in many cases, works on multiple platforms (PC, PS4, XBO). The developers can’t dictate what type of storage is in the console, so game data needs to be stored in a way that works for the lowest common denominator, the spinning HDD. Game levels and assets like models, audio, and generally any files associated with a level, are typically duplicated and stored directly adjacent to each other so the HDD read time is minimized. (Insomniac Games have a really good explanation of this in this GDC 2019 talk @ ~25 minutes) If the game assets were only stored once then the overall size of the game would be smaller, but those assets would be spread out on the disk and have to be read into memory when needed, meaning that disk would have to spin and pivot and read a lot… Lots of time… Loading every asset into memory once is an option, but typically the console doesn’t have enough memory to store everything at one time. Also, loading the entire game into memory would potentially take a long time and many assets wouldn’t even be needed in a given play session. Referencing the GDC 2019 presentation linked above; here is an image of just how much was duplicated for Marvel’s Spider-Man (2018).

That is a massive cost regarding size on disk, but consider that now the assets attached to a given level can be read in much faster, resulting in a better gaming experience with less loading issues during gameplay.

That was the past. Current generation consoles now make use of onboard NVMe storage, which is much faster than SATA. Architecturally, NVMe is a storage rewrite that uses PCIe lanes, communicates directly with the CPU, and is solid-state exclusive. There are no spinning NVMe drives. For comparison:

Storage Interface Type (Console)Maximum Speed (MB/s)
SATA II (PS3, PS4, X360, XBO)300 MB/s
12 Channel NVMe (PS5)5500 MB/s (Raw)
8000-9000 MB/s (Compressed)
22000 MB/s (Compressed / Peak)
XVA NVMe (XSX)2400 MB/s (Raw)
4800 MB/s (Compressed)
Storage Interface Speed Comparison

Those NVMe speeds are staggering, but lets talk about raw vs compressed and the PS5/XSX difference. Raw throughput speeds are achieved by streaming raw data straight from the NVMe SSD to the CPU. This is simply moving an amount of data from Point A to Point B. To save on SSD space consumption the PS5 and XSX have hardware decompression built-in, allowing developers to compress data in a way that the consoles can decompress very efficiently and quickly. Compressed throughput speeds are achieved by streaming the compressed data to the built-in decompression engine and having the decompressed data streamed to the CPU.

“Overall the Xbox Series X seems to take a little longer getting into games, but once inside the differences between the two consoles as far as loading speeds seem negligible.”

Mike Fahey, Kotaku

The storage speed differences between PS5 and XSX seem drastic if you just pay attention to the specs, but consider that game developers will need to work diligently to employ the full power of these new storage mechanisms. Console exclusive games are expected to capitalize on this outright, whereas cross platform games would need to be optimized for each console. Mike Fahey of Kotaku showcases several cross platform games loading, and concludes: “Overall the Xbox Series X seems to take a little longer getting into games, but once inside the differences between the two consoles as far as loading speeds seem negligible.” Previous generation games running on the PS5 or XSX stand to gain from the performance benefits of the NVMe storage regardless of code or asset optimization; though, many developers are releasing patches for previous generation titles with extreme results. One brilliant benefit of NVMe is that it is no longer required to duplicate objects for the sake of hard drive seek times. This is expected to result in the same game at smaller sizes.

The future is bright for console gamers! Every generation sees increased graphics capability, but this is the first big storage technology jump since the inclusion of onboard storage. More computational power, better graphics, and faster access to data, allow developers to focus fully on the gaming experience instead of tricks and tradeoffs to accommodate hardware constraints. It is almost like consoles are becoming PCs. 🙂