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Tegra K1’s CPU: An Updated 4+1 Cortex-A15 Design

Nvidia Tegra K1 In-Depth: The Power Of An Xbox In A Mobile SoC?
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Nvidia and Samsung both utilize cores designed by ARM, while Qualcomm and Apple build their own cores using ARM’s instruction set. Tegra 4 was Nvidia’s first effort based on Cortex-A15, and it ran at clock rates up to 1.9 GHz. The company sticks with Cortex-A15 in its 32-bit Tegra K1, but makes some improvements that it claims facilitate up to 40% more performance at the same power level or allow the SoC to use 45% of the power at a specific performance point in SPECint2000.

Nvidia's four Cortex-A15 cores share a 16-way set associative L2 cacheNvidia's four Cortex-A15 cores share a 16-way set associative L2 cache

Those are some fairly substantial claims given the same processor generation. Yet, Nvidia says that they’re the product of three factors. First, its engineers have all of that time building Tegra 4 under their belts. Although this is Cortex-A15, there are purportedly some layout-related optimizations unique to Nvidia’s implementation. The shift from TSMC’s 28 nm HPL to HPM process brings dynamic power down a bit as well. Finally, ARM is on its fourth revision of Cortex-A15. Tegra K1 employs r3p3 (the third revision), whereas Tegra 4 was based on r2. According to ARM’s technical documentation, most of the changes between the two SoCs are related to regional clock gating and a couple of other configurable power-saving options. Estimates put the performance/watt improvements between 5 and 10%. As a result, Nvidia reaches clock rates as high as 2.3 GHz with the quad-core Tegra K1.

The flexibility to choose between higher performance or lower consumption means that Nvidia can allocate its power budget more freely than the generation prior, scaling back on the CPU in favor of its graphics engine, for example. In graphics-bound applications, this is precisely what you’d want to see. Doubly so given Tegra K1’s broader API support, which at least make it technically feasible for developers to port higher-end titles down to Android-based tablets.

Notably less was said about the dual-core Denver-based model, except that its wide superscalar execution pipeline should facilitate notably better threaded performance and fast single-core speed at clock rates of up to 2.5 GHz.

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  • 0 Hide
    Marcopolo123 , January 6, 2014 6:50 AM
    funny
  • 0 Hide
    azzazel_99 , January 6, 2014 6:56 AM
    .
  • 0 Hide
    renz496 , January 6, 2014 8:12 AM
    Quote:
    Where is the maxwell stuff did they not even address it yesterday? WTF


    most likely they will talk about it when the actual gpu is close to release.
  • 8 Hide
    Wisecracker , January 6, 2014 8:38 AM
    Quote:
    At least in theory, Tegra K1 could be on par with those previous-generation systems ...


    AMD does it. Intel, too. But ...

    When it comes to over-the-top hype, embellishment and hyperbole, nVidia is the king.

  • 2 Hide
    ZolaIII , January 6, 2014 10:04 AM
    @ Rupert Jr

    Well multiplied 3x & with higher memory bandwidth you are there.
    1.5x Maxwell & 2x cores (28nm to 16-14nm).
    Hyper memory cube.
    All this in 2015.
  • -2 Hide
    RupertJr , January 6, 2014 10:11 AM
    @ZolaIII
    but what you are assuming does not exists nowadays and maybe until years...
    where will be other chips at that time?
  • 2 Hide
    dragonsqrrl , January 6, 2014 10:48 AM
    "in fact, the first Maxwell-powered discrete GPUs are expected in the next few weeks"

    Excellent.
  • 5 Hide
    InvalidError , January 6, 2014 11:07 AM
    Quote:
    It looks like NVidia will loose another battle...

    Well, they are right on at least one thing: 2014's SoCs are now about on par with high-end components from ~7 years ago or mid-range gaming PCs from ~5 years ago and are managing to do so on a 2-3W power budget, which is rightfully impressive IMO.

    If SoCs continue improving at this pace while PCs remain mostly stagnant, the performance gap between SoCs and mainstream PCs will be mostly gone by the time 2015 is over.
  • 0 Hide
    Shankovich , January 6, 2014 11:27 AM
    I'm assuming this SoC will run at around 15 watts. With 192 CUDA cores and DDR3 LP, your max output will probably be somewhere around 180 GFLOPS. Yes yes it CAN do the same effects as consoles and PC, so what? If the Game Cube had DX 11.2 api running on it, it could as well, but obviouslt it coiuldn't put too much on the screen. This will be the same deal with the K1.

    It's cool, I like it, don't get me wrong, but the stuff they're saying, though technically correct, is so misleading to about 90% of the market. People are going to think they have PS4's in their hand when in reality they have half a xbox 360 with up to date API's running on it.
  • 5 Hide
    Shankovich , January 6, 2014 11:48 AM
    Ah crap that's what I get for posting before reading everything -_-. Well, in retrospect I say I'm very surprised! 365 GFLOPS peak is amazing for what it's running off of! However, it really doesn't come close to competing with any current gen console or base gaming PC. I'd love to have a ultrabook running around 800 GFLOPS in the near future though :) 
  • 0 Hide
    photonboy , January 6, 2014 11:49 AM
    Factor of 10??

    Would it not be a factor of 100?
    (200W/2W)
  • 2 Hide
    esrever , January 6, 2014 12:49 PM
    nvidia forgot it rated the ps3's GPU 2TFLOPs to market it to sony.
  • 0 Hide
    redeemer , January 6, 2014 1:54 PM
    Quote:
    Where is the maxwell stuff did they not even address it yesterday? WTF



    That says a lot right there, Maxwell is far away!
  • 0 Hide
    redeemer , January 6, 2014 1:56 PM
    Quote:
    Where is the maxwell stuff did they not even address it yesterday? WTF



    True but K1 at the right price can be a force in the SOC arena
  • 0 Hide
    redeemer , January 6, 2014 2:15 PM
    So another things guys no mention of current products Tegra 4 /4i...lol, all I see is Tegra 5/6. Nvidia has to stop this non-sense they are all over the place, so I guess Tegra 4 is dead in the water not that it was being adopted well anyways. Nvidia is good at building Tegra hype but can never deliever. Hopefully they do not mess up k1!
  • 0 Hide
    apache_lives , January 6, 2014 2:16 PM
    http://www.news.com.au/technology/california-crop-circle-was-a-marketing-stunt-by-nvidia-corp/story-e6frfrnr-1226796160776
  • 0 Hide
    Durandul , January 6, 2014 3:15 PM
    Quote:
    Factor of 10??

    Would it not be a factor of 100?
    (200W/2W)


    It would be except they take into account that there is only one SMX rather than eight. So it would really be (25W/2W).

    On a side note, if a company like Epic Games were to go back and do a thorough port of UDK 3, I believe it would be reasonable for a publishing company like 2K to either have it's developers go back and recompile the games, or hire new ones to do so, and we might see a market emerge for the K1.

    The dream scenario for me would include having Sony add drivers for the dualshock to android, and being able to play borderlands on a tablet with it. Now if only there were someone to throw money into their faces...
  • 2 Hide
    Durandul , January 6, 2014 3:18 PM
    Quote:
    So another things guys no mention of current products Tegra 4 /4i...lol, all I see is Tegra 5/6. Nvidia has to stop this non-sense they are all over the place, so I guess Tegra 4 is dead in the water not that it was being adopted well anyways. Nvidia is good at building Tegra hype but can never deliever. Hopefully they do not mess up k1!


    Actually, the article mentioned that 4i was still going to be released in the first half of 2014 as a solution for phones. Makes you wonder why they bother after reading the article however.
  • 0 Hide
    InvalidError , January 6, 2014 10:39 PM
    Quote:
    Nvidia has to stop this non-sense they are all over the place, so I guess Tegra 4 is dead in the water not that it was being adopted well anyways.

    Tegra3 launched several months late, just before everyone else released their new next-gen SoCs so it was too little too late to have much of a chance to gain much market share. Tegra4 was largely in the same boat and I'm guessing many device manufacturers may have shied off due to lack of unified shaders and GPGPU too.

    If Tegra5/K1 is delivered on-schedule and is priced right, it should have a decent shot at the market. That's a lot of ifs with a sub-par track record so Chris' implied skepticism (as well as many people in these comments, myself included) is very well warranted.

    Time will tell.
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