Intel’s Second-Gen Core CPUs: The Sandy Bridge Review

The System Agent And Turbo Boost 2.0

The System Agent

Altered principally in name, the system agent includes functionality previously associated with the uncore—that is, it includes the processor subsystems that can’t be grouped with the execution cores (and now the graphics engine, too).

In that list, you  have the dual-channel memory controller (which officially supports transfer rates of up to 1333 MT/s), 16 lanes of second-generation PCI Express connectivity, the DMI, and a more advanced power control unit, responsible for managing the operation of Turbo Boost, among its other roles.

Turbo Boost 2.0?

Speaking of Turbo Boost, Sandy Bridge includes a second-generation implementation of this technology, first seen two years ago on Bloomfield-based Core i7-900-series chips, but really only throttled up, so to speak, on Lynnfield a year later.

The premise behind what I’ll call Turbo Boost 1.0 was that, in a multi-core CPU, available resources are not always in use. An application like iTunes, for instance, can only use one core at a time. And yet, the chip’s thermal ceiling is defined by a worst-case scenario of all cores fully-utilized. Turbo Boost takes advantage of the thermal headroom that exists when the chip executes a workload like iTunes, in turn accelerating the one active core to get its task completed faster.

Turbo Boost 1.0 is smart in that it dynamically ratchets up the frequency of active cores based on temperature, current, power consumption, and operating system states. But it won’t exceed programmed power limits, even if thermal headroom exists to push performance harder.

In the real-world, a processor doesn’t heat up right away, though. From idle, it takes time to reach its thermal ceiling. Turbo Boost 2.0 (or next-gen Turbo Boost, whatever you want to call it) allows the processor to exceed its power ceiling until it reaches its thermal limit, at which point it drops power to conform to those same programmed limits.

Turbo Boost 2.0 does not mean the CPU will exceed its maximum Turbo Boost frequency. If you have a Core i7-2600K with a 3.4 GHz base clock and 3.8 GHz maximum Turbo clock, 3.8 is as fast as it’ll go in its stock trim. It’ll simply stay there longer—until the CPU heats up to its thermal limit—before backing down.

Unfortunately, it’s not really possible to quantify the benefits of this capability. The best I could get out of Intel was that it helped improve responsiveness. On the desktop, I frankly wasn’t able to tell a difference, and as a result, Turbo Boost 2.0 comes across somewhat gimmicky.

To be fair, it’s going to mean more in the mobile space, where base clocks start off a lot lower to save power, and Turbo Boost ceilings scale significantly higher. We have a Sandy Bridge-based notebook in the office and will be putting it through its pages this month, too.

Also more impactful in the mobile space is Sandy Bridge’s ability to share thermal budget between graphics and processor cores. Previous-generation Arrandale cores were able to do this, applying the Turbo Boost concept to both components. Now Sandy Bridge enables the same capability on the desktop. Intel says that, in 3D-heavy workloads, the power control unit will bias to the graphics core, as it stands to improve performance more than faster CPU cores.

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  • mi1ez
    Great looking processors, tainted by a US only competition.
  • aje21
    I was wondering if the HTPC market would be best served by a return to the "mobile on the desktop" approach which was popular during the Pentium 4 era.
  • Anonymous
    Please correct the LGA1555 value on "o Meet Intel’s Second-Gen Core CPUs" to LGA 1155.
    Thanks in advance,
  • dillyflump
    Sorry im really not sold on the idea of intergrated gpu's. The intergration of the PCIe bus is a good idea, but i wouldn't want to run the risk of having a chip failure. You would effectively loose two components instead of just the cpu.
  • Anonymous
    Any chance you could update this review with screengrabs that show the image quality difference between MediaConverter 7 and MediaEspresso 6? I'm curious why the latter program rendered the video file in only half the time.
  • AnUnusedUsername
    It seems that to anyone who uses dedicated graphics, these chips are more or less just more expensive but otherwise not significantly different from the older ones.. Unless integrated graphics on a CPU can beat dedicated, whats the point of including it on any processor thats selling for more than $150 or so? No one is going to pay more than that for a processor and not use dedicated graphics, so its just wasted space and an increased cost that gets users nothing. Seems to me that Intel is just out of ways to noticably improve performance, since higher clock rates get too hot and more cores aren't coded for, so they are just adding more clutter to their chips and selling them as something new... not saying it was simple, but it seems pretty useless to me. Maybe the next release from intel will take advantage of the more advanced CPU and drop the integrated graphics so we get effectively the same performace at a lower price.
  • chechak
    H67 does not support processor overclocking + Sandy Bridge HD graphic 3000 suck + no usb 3.0 + Sandy Bridge processors are not compatible with Intel’s 5-series chipsets = intel customer wrath :S !!!
  • mosox
    I fail to see anything that changes the game. Another Intel socket that will have only a handful of CPUs on it. No 6 core CPUs on that.
  • wild9
    mosoxI fail to see anything that changes the game. Another Intel socket that will have only a handful of CPUs on it. No 6 core CPUs on that.

    Maybe Ivy Bridge at 22nm, will offer more than 4 physical cores.

    But I feel a similar way to you. Take away the potential of the HD 3000 (which Intel has done with most of the Sandy Bridge portfolio), and what have you got? HD 2000, ring bus and restricted overclocking. Would the average Joe be willing to run out and ditch their i5 for this? Hmm. If the vast majority of these products had Hyper-Threading and HD 3000, I'd be more inclined to say yes. But the current i5 already incorporates decode assist hardware to speed up video transcoding in apps like CyberLink MediaEspresso. As a result the gap between present Core i5 HD graphics and the new Sandy Bridge HD 2000 isn't massive, least not by this measure.


    Even at stock the current i5 doesn't seem too bad compared to the new i3 and i5, and you can always overclock. So for games in particular I'd just spend it on a faster discrete GPU rather than upgrade to Sandy Bridge.

    As for AMD. Well, once again Intel has fired first with what it perceives to be a silver bullet. Except you have to rummage through a pile of fake bullets to aim straight; 75% of the Sandy Bridge portfolio excludes Intel HD 3000. Thus accelerated computing, and to a greater extent on-die 3D gaming performance, will suffer (AMD 890GX still packs a gaming/hd media playback punch compared to Intel HD 2000). So for everything but media transcoding that just leaves ring bus, controversial overclocking features and a somewhat tight-fisted attitude towards Hyper-Threading on quad-core CPU's..not be a big enough reason for me to ditch my current hardware. AMD's approach seems quite the opposite, focusing on socket longevity and putting next-gen technology in everyone's hands, rather than just the few who can afford it.
  • mosox
    The new CPUs look like semi-workstation CPUs to me. Not really much better in gaming but sensibly better in some other areas. I don't know if that's a mainstream direction, I mean who encodes/archives all day long?

    I want AMD to keep on producing cheapo quads and triple cores for the budget gamers out there (I am one). A $100 quad with L3 cache would be nice. And cheap mobos too. Let Intel do its thing on the high end market and concentrate on the 1 billion dudes and dudettes in Africa/China/India/E Europe who want to play Crysis on a cheap rig with a SH Raidmax PSU, an old IDE HDD and the cheapest CPU that can run the game on a 19" monitor.
  • Anonymous
    Cheeky! I game on a 22" screen at 1680 x 1050 thank you very much! I run an HD5850 and core2quad 9450 @ 3.2GHz
  • mactronix
    A lot of people are down on this release and its easy to see why. Personally i want My CPU to do CPU type things and my GPU to do the Graphics.
    That said its a fine standard to set for a gaming machine, however there are plenty of people who just want to make a PC that will handle vidio which Sandy bridge does plenty well enough. Surf the net and play the odd game. For this type of build you just saved on the cost of the Motherboard and you dont need a GPU at all.
    Everything has to start somewhere and teh GPU side of the package will only get better as we go into 22nm and beyond. Games are not getting anymore taxing and pretty soon. 3 years i will say, i can see only hardcore gamers even needing a discrete GPU at all.

  • Anonymous
    Any enthusiast/gamer will be ignoring the integrated gfx and focussing on the K variants. And from this view point, you now have a new CPU that makes almost every other processor completely redundant. No one in their right mind is going to choose P55/X58 over these.

    As an upgrade from an existing i5/i7 setup its not worth it - did anyone really expect it to be? But for a new build or an upgrade from a S775/Q6600 for example, tis a no brainer!
  • strat4axe
    With Sandy Bridge and the forthcomming Bulldozer cpu's on their way,as they develop is it going to be possible to use the on die GPU as a physics engine with a discrete graphics card?Like a hybrid graphics solution,only one that's worth bothering with?
  • strat4axe
    GO away this ain't ebay
  • Gonemad
    mmmkay, these chips ain't exactly targeted at enthusiasts, and a bit of feature malfunction there releasing HD 3000 graphics chip thingie on top tier desktop parts, instead of budget/mainstream, but I certainly do see potential on video encoding for those that live of it.

    On another point of view, discrete sound and network cards were sent on the way of the dodo, when motherboards came with them embedded, leaving behind only really top players in their fields, namely Gigabit NIC, and top-tier soundcards with dedicated or special-purpose hardware.

    I see this trend again, when the CPU has graphic muscle enough to make a discrete graphic card redundant. I mean, one benchmark showed one of these cards tie up with a Radeon HD 4550 and still don't believe it. I see interesting benchmarks on the budget section in the days ahead, where an Intel solution may actually show up on the FPS charts.
  • wild9
    8 consecutive spam messages in a row, with several hours between messages.

    This suggests that a) these spammers are having a field day, and b) that users are avoiding posting altogether due to the sheer volume of spam. I trawled through so much junk to post this, that I almost forgot what I originally came here for.

    Maybe this isn't the place to say it, and I wish to point out I am not trying to say it for no real reason.

    Tom's, what is going on to this great community? These spammers are making a complete and utter mockery of your operation. I like coming here and reading the tech news including people's feedback but if these spammers keep attacking the site like this, it's not worth it for me. I'm wasting time trawling through rubbish and the frustration this causes is really making me look elsewhere. I am confident every other legitimate member of this service feels the same way.

    Why not give trusted users low-level moderator status? Or how about a filter that declares any posts containing text from a spam database, as null and void? I spot several spam posts using the same url, for instance..there's 4 above that could have been wiped out in an instant.

    This is getting crazy, guys. They're ruining it for others.
  • mosox
    Probably that's about what you can get if not upgrading unnecessarily to Sandy Bridge. :)
  • Mudit Sathe
    Why a core 980x is not used in this benchmarks?
  • weefatbob
    mi1ezGreat looking processors, tainted by a US only competition.

    And every price, for this article posted on UK site, is in dollars too!