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Core i7-2820QM: Sandy Bridge Shines In Notebooks

Core i7: Running The Gamut

In the past, Intel has used a handful of modifiers to further distinguish its model numbers: M, LM, UM, QM, and XM. There aren't any unlocked mobile processors, as overclocking generally isn't something power-conscious notebook users wish to inflict upon their batteries. This explains the lack of K-series SKUs on the mobile side.

Expectantly, M is the primary designator signaling the difference from mobile and desktop products. There are additional mobile offerings that substitute an E for M, which is a further subset of the mobile product line that indicates embedded processor packages. Everything else is pretty straightforward: L for Low Voltage, U for Ultra Low Voltage, Q for Quad-Core, and X for Extreme Quad-Core.

Today, we are looking at a fairly beefy selection of mobile Core i7s. If the performance of the desktop parts is any indicator, this is an exciting prospect. We are talking about some serious processing power at ultra-low and low-voltage power profiles.

As an aside, if you look at the whole Sandy Bridge mobile lineup, you will notice a lack of L- and U-designated processors. This can be explained away by the last digit of the model name. Models that end with 9 indicate LV parts, while 7 is for ULV. This is somewhat of a departure from the company's previous mobile scale.

Core  / Threads2 / 42 / 42 / 42 / 42 / 4
Base Clock2.7 GHz2.3 GHz2.1 GHz1.6 GHz1.5 GHz
Max. Turbo Clock3.4 GHz3.2 GHz3.0 GHz2.7 GHz2.6 GHz
Memory (MT/s)13331333133313331333
L3 Cache44444
HD Graphics30003000300030003000
Max. Graphics Clock1300 MHz1100 MHz1100 MHz1000 MHz950 MHz
AVX SupportYesYesYesYesYes
Quick Sync SupportYesYesYesYesYes
AES-NI SupportYesYesYesYesYes

As we noted in our launch coverage, there are actually three different versions of the Sandy Bridge die shipping at launch. The quad-core configuration—the one composed of 995 million transistors—measures 216 mm². Then, there’s a dual-core die with 12 execution units making up its graphics engine. That one features 624 million transistors on a 149 mm² die. Finally, the slimmest variation sports two cores and a graphics engine composed of six EUs. You're won't see that last version represented in Intel's current mobile lineup, since the complete portfolio is made up of dual- and quad-core CPUs with HD Graphics 3000. Moreover, all of the mobile CPUs enjoy Hyper-Threading support, a benefit missing from about half of the desktop line, including our recommended i5-2500K.

Die Size (square mm)Transistors (million)
Sandy Bridge (4C)216995
Sandy Bridge (2C, HD Graphics 3000)149624
Sandy Bridge (2C, HD Graphics 2000) - Desktop Only131504
Bloomfield (4C)263731
Lynnfield and Clarksfield (4C)296774
Westmere and Arrandale (2C)81383
Gulftown (6C)2481168

Another difference is the introduction of another new interface. The mobile world doesn't have the same issues to worry about as desktop PC. So, although its second-gen Core CPUs share a similar architecture, they employ dissimilar processor interfaces. The new Core i7 Mobile CPUs drop into an rPGA 988 socket, which is one pin short of the mPGA 989 seen on the previous Clarkdale-based i7s. That's right; Intel is breaking compatibility with its first-gen Core chips on the mobile side, just as it did on the desktop. Fortunately, processor upgrades are less prevalent in notebooks, so this move should affect enthusiasts far less.

And whereas the desktop chips are pinless, mobile Core i7s actually wear the pins in this relationship. Though, we should point out that we haven't even listed all variations of the mobile Core i7s. The ---9M (LV) and ---7M (ULV) parts come in BGA 1023, while the 55 W and 45 W also come in a BGA 1224 package. If that doesn't make things confusing, other models end in ---5. This seems to be the only differentiation between BGA and rPGA specific packages.

Everything in the architecture and technical details that we explained in our launch coverage of Sandy Bridge also applies to the mobile side, such as Quick Sync and Turbo Boost 2.0, and we suggest that you read over our earlier article if you haven't done so already.

  • cmartin011
    Second!!! really a thousand dollars for a mobile cpu
  • one-shot
    What are the numbers for battery life for idle, surfing the web, and watching HD video? Several reputable sites have posted up numbers and I'm not seeing a chart that states these numbers, just lots of performance numbers to reiterate the obvious that it's more powerful and more efficient than Arrandale CPUs.
  • acku
    This isn't a production notebook so battery life pertaining to this specific notebook is rather pointless in relation to other models. There are other factors at play: LCD panel, battery density, etc... However, platform power consumption numbers are posted on the second to last and last page.

  • one-shot
    ackuThis isn't a production notebook so battery life pertaining to this specific notebook is rather pointless in relation to other models. There are other factors at play: LCD panel, battery density, etc... However, platform power consumption numbers are posted on the second to last and last page.AndrewTomsHardware
    That isn't what I was looking for. On Anandtech and Tech Report, a Compal notebook with a Core i7 2820QM achieved between six and seven hours of battery life when web browsing. I was looking for a comparison to help me make a more informed decision.

    Something like these is what I was referring to.

    Battery life is not pointless in any way. A pre-production model or not, it's relevant. If helps give us, the consumers, a better perspective to how laptops with these CPUs will perform with regards to battery life.

    I'm surprised it wasn't included.
  • acku
    Fair point and I completely agree that battery life is not pointless. But on our point, we did go over power as far as browsing and Flash video if you read our conclusion.

    On an platform level, you can expect a new Sandy Bridge Core i7 to achieve roughly double the battery life of a notebook with an Arrandale Core i5.

    What I disliked about the previous benchmarks (including the ones you referenced) was that they automatically handicapped the benchmark against the Sandy Bridge mobile platform. Forget the whole DTR argument. A 17.3" panel will generally consume more power than a 15.6" (Look at the notebooks it was compared against.) When you isolate it down to the platform level then you can say all-else-being-equal (LCD, hard drive, wireless card, etc...), a notebook based on a Sandy Bridge mobile processor will ~ double battery life. Those other sites showed a roughly 33% improvement because of the other variables at play.

    Remember though that when you are talking about H.264 playback, this is all run through the hardware decoder. You are getting very little battery burn no matter what hardware you are running. What really matters then is the total platforms power consumption and the density of your battery (2.6AH vs 2.9AH cells).

    But back to your main point, if that is what you want to see on a DTR, then we will include it next time. Frankly, I'm more interested in the battery life of non-DTR mobile CPUs. "Normally" people don't care about battery life on a 17.3" mobile workstation.
  • bearclaw99
    Damnnnnn...those are some amazing benches for a laptop CPU. Beats some of the desktop i7s and probably all of AMDs desktop chips
  • SteelCity1981
    If AMD is paying attention, it needs to get its act in order. Brazos is one step up from being a pawn in the AMD Fusion chess set.

    AMD's Brazos platform is very impressive especially the E-350 series that's paired with an Radeon HD 6310 in gaming performance. Soo impressive in fact that the gaming performance rivals that of Core i5 661 in a lot of games and even goes toe to toe with the Core i5 2500k in some games like Call OF Duty Black Ops! As show here....
  • _Pez_
    amd is losing ground.. they are taking too long releasing new products.. Intel is expensive.. damm!
  • hardcore_gamer
    I think bulldozer will be able to compete in terms of TDP because of the two integer units / core
  • Vadim_79
    I just bought myself an Asus N53SV a couple of days ago, so far it's been great, it can handle any game i throw at it due to the combined intel 3000 and gf540m. Whenever i use the notebook for things like surfing the web it uses the intel 3000, so i get better battery life. I game with the notebook plugged in and set to maximum performance on a 42 inch plasma through hdmi. And it beats my desktop as far as framerates are concerned