The Sphere in Las Vegas features 4PB of flash memory at 400 GB/s to deliver 16K content

News
By Christopher Harper
published

Sphere Entertainment shares technical details of its ambitious display array

Shot of The Sphere in action from Sphere Entertainment's promo YouTube video.
Shot of The Sphere in action from Sphere Entertainment's promo YouTube video. (Image credit: Sphere Entertainment)

The massive Las Vegas Sphere, whose exterior doubles as the most giant LED screen ever, has drawn much attention since it first appeared. However, a Sphere Entertainment blog post only recently provided a more detailed explanation of how it works. The Sphere, run by Sphere Entertainment Co., and Hitachi Vantara, a subsidiary of Hitachi focused on data processing, cloud storage, and other infrastructure concerns recently provided far more information about how Hitachi Vantara's infrastructure and software to stream such high-resolution video.

The Sphere measures 580,000 square feet, while the inner side measures 160,000 square feet. The Sphere is capable of some truly outstanding visuals. From planets and moons to trippy art pieces, the outside of the Sphere is more than well-equipped for its high-res projection purposes. Since it was activated for the first time on July 4, 2023, with a high-res view of Earth, it has consistently been praised for its novelty—though one day it may become a Times Square-esque advertiser's surface, which is much less exciting.

Reportedly, both the internal and external screens support 16K resolution video output. They each rely on a collection of 27 nodes, each streaming at 4K through Hitachi Vantara's software, with a whopping 4 Petabytes (1 Petabyte = 1000 TB) of flash memory capable of 400 GB/s speeds. Full 4:4:4 chroma subsampling is also used, and reportedly, the displays can achieve a latency of around five milliseconds or less.

If all of this display spec sounds ridiculously overpowered for modern cameras, movies, and games that aren't running anywhere near 16K resolution...you're right. However, this problem is being addressed by appropriately optimizing existing display content and by Sphere Entertainment's very own "Big Sky" camera, which can capture up to 18K resolution. While your indie filmmakers aren't getting their hands on this, there are, fortunately, solutions to the technical challenge of hitting 16K resolution.

While the outside of the Sphere is the most obviously impressive part at a glance, footage from inside the Sphere has also been shared on Twitter and should provide some highly immersive cinema experiences. The internal video clip we've linked highlights a sense of feeling tiny within the dome while consuming content since it all ends up "wrapping" around the viewers. It'd be like if a movie theater started treating their screens like ultrawide multi-monitor setups.

Correction, March 18, 2024: This story initially suggested the Sphere was a joint project between Sphere Entertainment Co. and Hitachi. Rather, the Sphere is run solely by the former, using tech by Hitachi Vantara. We regret the error.

Christopher Harper
13 Comments Comment from the forums
  • Geef
    For something so big like that I really hope they keep that thing completely offline. If someone hacked that and started playing _ornhub videos, that could be bad! :eggplant:
    Reply
  • USAFRet
    Geef said:
    For something so big like that I really hope they keep that thing completely offline. If someone hacked that and started playing _ornhub videos, that could be bad! :eggplant:
    Completely offline? Highly unlikely.

    The admins have to get into it somehow, and its not like they are going to swap out physical drives.
    Reply
  • bit_user
    I already heard some of these specs on a news program's coverage of The Sphere. I turned to it in the middle of the segment, so I didn't know what they were talking about. The numbers were so mind-blowing that it immediately caught my attention.

    This is one of the first times I've heard of something in Vegas I think I actually want to see.

    They each rely on a collection of 27 nodes, each streaming at 4K through Hitachi Vantara's software, with a whopping 4 Petabytes (1 Petabyte = 1000 TB) of flash memory capable of 400 GB/s speeds.
    IMO, it's more interesting to consider the specs of the individual nodes. So, 4 PB = 148 TB per node. That works out to about 4.6 * 32 GB datacenter SSDs per node, which is very plausible.

    The data rate works out to 14.8 GB/s, so they're definitely using a RAID of some sort. While the fastest PCIe 5.0 client SSDs can basically hit that, I doubt they can reliably sustain those speeds.

    I do wonder what data rate they're actually using. If we consider storing an hour of footage in 148 TB, it works out to 41.1 GB/s. Now, I know they can rotate between different shows, so probably the storage capacity should hold more like 3 or 5 hours of footage, but that's still an astonishingly high data rate for compressed video - even at 4k.

    A raw 4k frame @ 4:4:4 and 16 bits per channel is only 49.7 MB. So, that's about 3 GB/s at 60 fps. 148 TB would let you store 13.78 hours at 60 fps. If we double the frame rate to 120 fps (which makes sense, if you imagine their display panels probably reuse some circuitry from commodity OLED TVs), then we end up with 6.9 hours of storage capacity, which is roughly where I expect it would be.

    Huh. So, they're really storing uncompressed video on these nodes? I wonder why. Sure, the simpler your data path, the fewer things can go wrong, but talk about brute force...

    I've heard digital cinema uses MJPEG or JPEG 2000. The reason probably being that an error in the datastream would only cause a glitch to occur in part of a single frame, rather than affecting the rest of the GOP. Also, no chance of motion artifacts.

    Full 4:4:4 chroma subsampling is also used, and reportedly, the displays can achieve a latency of around five milliseconds or less.
    I wonder if they even use YUV. For 4:4:4, you could just encode RGB and even avoid the colorspace transform when displaying.

    I also wonder a little bit how they keep the playback machines & displays synchronized. For the machines, I'd guess NTP at a high polling rate? I think synchronization at about 1 ms should be adequate, though not excessive if you consider the amount that an image can move during rapid pans (having poor synchronization would result in tearing). As for the displays, "Gen-lock" is nothing new... it dates back to the era when TV stations would switch between analog feeds, and you needed each signal source to be at the same v-sync to avoid glitches. I've even seen it listed as a feature on some Nvidia Quadro cards, a while back.

    Last among my questions is what OS they're running. I'd guess probably Linux with "RT" patch set. That's what I'd use, any way. We should also consider that they're utilizing a Hitachi storage solution targeted at a much larger application domain, which I doubt supports true RTOS', nor do I expect it'd be worth porting to one.
    Reply
  • bit_user
    @TheyCallMeContra , the article appears to be missing the usual source link. I think this is the correct one?
    https://www.sphereentertainmentco.com/sphere-entertainment-and-hitachi-vantara-reveal-new-details-on-powering-high-resolution-video-content-at-sphere/
    Reply
  • vanadiel007
    I will wait until the resolution is 14 PK. 16K is a bit too low for me.
    Reply
  • TheOtherOne
    Does anyone have an idea how much electricity this thing uses? :homer:
    Reply
  • Findecanor
    I get triggered by the term "16K".

    Do they mean 16×1024, 16×1000 ... or ... 8×1920 which is the same as 15 × 1024 ?
    Reply
  • bit_user
    Findecanor said:
    I get triggered by the term "16K".

    Do they mean 16×1024, 16×1000 ... or ... 8×1920 which is the same as 15 × 1024 ?
    I was thinking about this... good question.

    The source link I found actually said nothing about the resolution (other than the individual panels being "4k")! What I've found elsewhere claims it's 16,000 x 16,000. That makes it 256 megapixels!

    I wonder how exact that is, because that's 4.17 times the width people usually mean by "4k panel". If the screen were actually 15,360 x 15,120, then you could tile it with a 4x7 array of 3840x2160 panels, which works out to 28 (not the 27 nodes mentioned). However, on that point, I found some further details of interest, including that apparently the data is "streamed in real-time to 7thSense media servers, each streaming 4K video at 60 frames per second". So, that means there needn't be 27 display panels, just because you have 27 nodes running "Hitachi Content Software for File, a high-performance, software-defined, distributed parallel filesystem storage solution".

    Another key detail mentioned in the link I cited is that they're using 12-bit color. So, I'd have to revise down my numbers a fair bit. TBH, I find the 60 fps thing most disappointing. With such a large screen, I'd expect the difference between 60 fps and 120 fps to be very noticeable.
    Reply
  • TheyCallMeContra
    bit_user said:
    @TheyCallMeContra , the article appears to be missing the usual source link. I think this is the correct one?
    https://www.sphereentertainmentco.com/sphere-entertainment-and-hitachi-vantara-reveal-new-details-on-powering-high-resolution-video-content-at-sphere/

    correct! not sure how that happened but that is indeed the primary source blog post being referred to in the intro
    Reply
  • ivan_vy
    Geef said:
    For something so big like that I really hope they keep that thing completely offline. If someone hacked that and started playing _ornhub videos, that could be bad! :eggplant:
    to prevent any unwanted stream get into it they can apply some delay to check with human or AI filter also is pretty sure the content is encrypted. if happens some hacking the cost on reputation would be far more bigger than any measures they can take it now.
    Reply