The Xbox One: Hardware Analysis & Comparison to PlayStation 4
by Anand Lal Shimpi on May 22, 2013 8:00 AM ESTPower & Thermals
Microsoft made a point to focus on the Xbox One’s new power states during its introduction. Remember that when the Xbox 360 was introduced, power gating wasn’t present in any shipping CPU or GPU architectures. The Xbox One (and likely the PlayStation 4) can power gate unused CPU cores. AMD’s GCN architecture supports power gating, so I’d assume that parts of the GPU can be power gated as well. Dynamic frequency/voltage scaling is also supported. The result is that we should see a good dynamic range of power consumption on the Xbox One, compared to the Xbox 360’s more on/off nature.
AMD’s Jaguar is quite power efficient, capable of low single digit idle power so I would expect far lower idle power consumption than even the current slim Xbox 360 (50W would be easy, 20W should be doable for truly idle). Under heavy gaming load I’d expect to see higher power consumption than the current Xbox 360, but still less than the original 2005 Xbox 360.
Compared to the PlayStation 4, Microsoft should have the cooler running console under load. Fewer GPU ALUs and lower power memory don’t help with performance but do at least offer one side benefit.
OS
The Xbox One is powered by two independent OSes running on a custom version of Microsoft’s Hyper-V hypervisor. Microsoft made the hypervisor very lightweight, and created hard partitions of system resources for the two OSes that run on top of it: the Xbox OS and the Windows kernel.
The Xbox OS is used to play games, while the Windows kernel effectively handles all apps (as well as things like some of the processing for Kinect inputs). Since both OSes are just VMs on the same hypervisor, they are both running simultaneously all of the time, enabling seamless switching between the two. With much faster hardware and more cores (8 vs 3 in the Xbox 360), Microsoft can likely dedicate Xbox 360-like CPU performance to the Windows kernel while running games without any negative performance impact. Transitioning in/out of a game should be very quick thanks to this architecture. It makes a ton of sense.
Similarly, you can now multitask with apps. Microsoft enabled Windows 8-like multitasking where you can snap an app to one side of the screen while watching a video or playing a game on the other.
The hard partitioning of resources would be nice to know more about. The easiest thing would be to dedicate a Jaguar compute module to each OS, but that might end up being overkill for the Windows kernel and insufficient for some gaming workloads. I suspect ~1GB of system memory ends up being carved off for Windows.
Kinect & New Controller
All Xbox One consoles will ship with a bundled Kinect sensor. Game console accessories generally don’t do all that well if they’re optional. Kinect seemed to be the exception to the rule, but Microsoft is very focused on Kinect being a part of the Xbox going forward so integration here makes sense.
The One’s introduction was done entirely via Kinect enabled voice and gesture controls. You can even wake the Xbox One from a sleep state using voice (say “Xbox on”), leveraging Kinect and good power gating at the silicon level. You can use large two-hand pinch and stretch gestures to quickly move in and out of the One’s home screen.
The Kinect sensor itself is one of 5 semi-custom silicon elements in the Xbox One - the other four are: SoC, PCH, Kinect IO chip and Blu-ray DSP (read: the end of optical drive based exploits). In the One’s Kinect implementation Microsoft goes from a 640 x 480 sensor to 1920 x 1080 (I’m assuming 1080p for the depth stream as well). The camera’s field of view was increased by 60%, allowing support for up to 6 recognized skeletons (compared to 2 in the original Kinect). Taller users can now get closer to the camera thanks to the larger FOV, similarly the sensor can be used in smaller rooms.
The Xbox One will also ship with a new redesigned wireless controller with vibrating triggers:
Thanks to Kinect's higher resolution and more sensitive camera, the console should be able to identify who is gaming and automatically pair the user to the controller.
TV
The Xbox One features a HDMI input for cable TV passthrough (from a cable box or some other tuner with HDMI out). Content passed through can be viewed with overlays from the Xbox or just as you would if the Xbox wasn’t present. Microsoft built its own electronic program guide that allows you to tune channels by name, not just channel number (e.g. say “Watch HBO”). The implementation looks pretty slick, and should hopefully keep you from having to switch inputs on your TV - the Xbox One should drive everything. Microsoft appears to be doing its best to merge legacy TV with the new world of buying/renting content via Xbox Live. It’s a smart move.
One area where Microsoft is being a bit more aggressive is in its work with the NFL. Microsoft demonstrated fantasy football integration while watching NFL passed through to the Xbox One.
Facebook
Twitter
RSS
245 Comments
View All Comments
JDG1980 - Wednesday, May 22, 2013 - link
In terms of single-threaded performance *per clock*, Thuban > Piledriver. Sure, if you crank up the clock rate *and the heat and power consumption* on Piledriver, you can barely edge out Deneb and Thuban on single-threaded benchmarks. But if you clock them the same, the Thuban uses less power, generates less heat, and performs better. Tom's Hardware once ran a similar test with Netburst vs Pentium M, and his conclusion was quite blunt: the test called into question the P4's "right to exist". The same is true of the Bulldozer/Piledriver line.And I don't buy the argument that K10 is too old to be fixable. Remember that Ivy Bridge and Haswell are part of a line stretching all the way back to the original Pentium Pro. The one time Intel tried a clean break with the past (Netburst) it was an utter fail. The same is true of AMD's excavation equipment line and for the same reason - IPC is terrible so the only way to get acceptable performance is to crank up clock rate, power, noise, and thermals.
silverblue - Wednesday, May 22, 2013 - link
It's true that K10 is generally more effective per clock, but look at it this way - AMD believed that the third AGU was unnecessary as it was barely used, much like when VLIW4 took over from VLIW5 as the average slot utilisation within a streaming processor was 3.4 at any given time. Put simply, they made trade-offs where it made sense to make them. Additionally, K10 was most likely hampered by its 3-issue front end, but it also lacked a whole load of ISAs - SSE4.1 and 4.2 are good examples.Thuban compares well with the FX-8150 in most cases and favourably so when we're considering lighter workloads. The work done to rectify some of Bulldozer's ills shows that Piledriver is not only about 7% faster per clock, but can clock higher within the same power envelope. AMD was obviously aiming for more performance within a given TDP. The FX-83xx series is out of reach of Thuban in terms of performance.
The 6300 compares with the 1100T BE as such:
http://www.cpu-world.com/Compare/316/AMD_FX-Series...
Oddly, one of your arguments for having a Thuban in the first place was power consumption. The very reason a Thuban isn't clocked as high as the top X4s is to keep power consumption in check. Those six cores perform very admirably against even a 2600K in some circumstances, and generally with Bulldozer and Piledriver you'd look to the FX-8xxx CPUs if comparing with Thuban, however I expect the FX-6350 will be just enough to edge the 1100T BE in pretty much any area:
http://www.cpu-world.com/Compare/321/AMD_FX-Series...
The two main issues with the current "excavation equipment line" as you put it is a lack of single threaded power, plus the inherent inability to switch between threads more than once per clock - clocking Bulldozer high may offset the latter in some way but at the expense of power usage. The very idea that Steamroller fixes the latter with some work done to help the former, and that Excavator improves IPC whilst (supposedly) significantly reducing power consumption should be evidence enough that whilst it started off bad, AMD truly believes it will get better. In any case, how much juice does anybody expect eight cores to use at 4GHz with a shedload of cache? Does anybody remember how hungry Nehalem was, let along P4?
I doubt that Jaguar could come anywhere near even a downclocked A10-4600M. The latter has a high-speed dual channel architecture and a 4-issue front end; to be perfectly honest, I think that even with its faults, it would easily beat Jaguar at the same clock speed.
Tacking bits onto K10 is a lost cause. AMD doesn't have the money, and even if it did, Bulldozer isn't actually a bad idea. Give them a chance - how much faster was Phenom II over the original Phenom once AMD worked on the problem for a year?
Shadowmaster625 - Wednesday, May 22, 2013 - link
Yeah but AMD would not have stood still with K10. Look at how much faster Regor is compared to the previous athlon:http://www.anandtech.com/bench/Product/121?vs=27
The previous athlon had a higher clock speed and the same amount of cache, but regor crushes it by almost 30% in Far Cry 2. It is 10% faster across the board despite being lower clocked and consuming far less power. Had they continued with Thuban it is possible they would have continued to squeeze 10% per year out of it as well as reduce power consumption by 15%, which if you do the math that leaves us with something relatively competitive today. Not to mention they would have saved a LOT of money. They could have easily added AVX or any other extensions to it.
Hubb1e - Wednesday, May 22, 2013 - link
Per clock Thuban > Piledriver, but power consumption favors Piledriver. Compare two chips of similar performance. The PhII 965 is a 125W CPU and the FX4300 is a 95W CPU and they perform similarly with the FX4300 actually beating the PhII by a small margin.kyuu - Wednesday, May 22, 2013 - link
... Lol? You can't simply clock a low-power architecture up to 4GHz. Even if you could, a 4GHz Jaguar-based CPU would still be slower than a 4GHz Piledriver-based one.Jaguar is a low-power architecture. It's not able (or meant to) compete with full-power CPUs in raw processing power. It's being used in the Xbox One and PS4 for two reasons: power efficiency, and cost. It's not because of its processing power (although it's still a big step up from the CPUs in the 360/PS3).
plcn - Wednesday, May 22, 2013 - link
BD/PD have plenty of viability in big power envelope, big/liquid cooler, desktop PC arrangements. consoles aspire to be much quieter, cooler, energy efficient - thus the sensible jaguar selection. even the best ITX gaming builds out there are still quite massive and relatively unsightly vs what seems achievable with jaguar... now for laptops on the other hand, a dual jaguar 'netbook' could be very very interesting. you can probably cook your eggs on it, too, but still interesting..lmcd - Wednesday, May 22, 2013 - link
It isn't a step in the right direction in IPC. Piledriver 40% faster than Jaguar at the same clocks and also clocks higher.Stop spreading the FUD about Piledriver -- my A8-4500m is a very solid processor with very strong graphics performance and excellent CPU performance for all but the most taxing tasks.
lightsout565 - Wednesday, May 22, 2013 - link
Pardon my ignorance, What is the "Embedded Memory" used for?tipoo - Wednesday, May 22, 2013 - link
It's a fast memory pool for the GPU. It could help by holding the framebuffer or caching textures etc.BSMonitor - Wednesday, May 22, 2013 - link
Embedded memory latency is MUCH closer to L1/L2 cache latency than system memory. System memory is Brian and Stewie taking the airline to Vegas vs the Teleporter to Vegas that would be cache/embedded memory...