Update: Be sure to read our Sandy Bridge Architecture Exposed article for more details on the design behind Intel's next-generation microprocessor architecture.

The mainstream quad-core market has been neglected ever since we got Lynnfield in 2009. Both the high end and low end markets saw a move to 32nm, but if you wanted a mainstream quad-core desktop processor the best you could get was a 45nm Lynnfield from Intel. Even quad-core Xeons got the 32nm treatment.

That's all going to change starting next year. This time it's the masses that get the upgrade first. While Nehalem launched with expensive motherboards and expensive processors, the next tock in Intel's architecture cadence is aimed right at the middle of the market. This time, the ultra high end users will have to wait - if you want affordable quad-core, if you want the successor to Lynnfield, Sandy Bridge is it.

Sandy Bridge is the next major architecture from Intel. What Intel likes to call a tock. The first tock was Conroe, then Nehalem and now SB. In between were the ticks - Penryn, Westmere and after SB we'll have Ivy Bridge, a 22nm shrink of Sandy.

Did I mention we have one?

While Intel is still a few weeks away from releasing Sandy Bridge performance numbers at IDF, we managed to spend some time with a very healthy sample and run it through a few of our tests to get a sneak peak at what's coming in Q1 2011.

New Naming

The naming isn’t great. It’s an extension of what we have today. Intel is calling Sandy Bridge the 2nd generation Core i7, i5 and i3 processors. As a result, all of the model numbers have a 2 preceding them.

For example, today the fastest LGA-1156 processor is the Core i7 880. When Sandy Bridge launches early next year, the fastest LGA-1155 processor will be the Core i7 2600. The two indicates that it’s a 2nd generation Core i7, and the 600 is the model number.

Sandy Bridge CPU Comparison
  Base Frequency L3 Cache Cores/Threads Max Single Core Turbo Intel HD Graphics Frequency/Max Turbo Unlocked TDP
Intel Core i7 2600K 3.4GHz 8MB 4 / 8 3.8GHz 850 / 1350MHz Y 95W
Intel Core i7 2600 3.4GHz 8MB 4 / 8 3.8GHz 850 / 1350MHz N 95W
Intel Core i5 2500K 3.3GHz 6MB 4 / 4 3.7GHz 850 / 1100MHz Y 95W
Intel Core i5 2500 3.3GHz 6MB 4 / 4 3.7GHz 850 / 1100MHz N 95W
Intel Core i5 2400 3.1GHz 6MB 4 / 4 3.4GHz 850 / 1100MHz N 95W
Intel Core i3 2120 3.3GHz 3MB 2 / 4 N/A 850 / 1100MHz N 65W
Intel Core i3 2100 3.1GHz 3MB 2 / 4 N/A 850 / 1100MHz N 65W

The names can also have a letter after four digit model number. You’re already familiar with one: K denotes an unlocked SKU (similar to what we have today). There are two more: S and T. The S processors are performance optimized lifestyle SKUs, while the T are power optimized.

The S parts run at lower base frequencies than the non-S parts (e.g. a Core i7 2600 runs at 3.40GHz while a Core i7 2600S runs at 2.80GHz), however the max turbo frequency is the same for both (3.8GHz). GPU clocks remain the same but I’m not sure if they have the same number of execution units. All of the S parts run at 65W while the non-S parts are spec’d at 95W.

Sandy Bridge CPU Comparison
  Base Frequency L3 Cache Cores/Threads Max Single Core Turbo Intel HD Graphics Frequency/Max Turbo TDP
Intel Core i7 2600S 2.8GHz 8MB 4 / 8 3.8GHz 850 / 1100MHz 65W
Intel Core i5 2500S 2.7GHz 6MB 4 / 4 3.7GHz 850 / 1100MHz 65W
Intel Core i5 2500T 2.3GHz 6MB 4 / 4 3.3GHz 650 / 1250MHz 45W
Intel Core i5 2400S 2.5GHz 6MB 4 / 4 3.3GHz 850 / 1100MHz 65W
Intel Core i5 2390T 2.7GHz 3MB 2 / 4 3.5GHz 650 / 1100MHz 35W
Intel Core i3 2100T 2.5GHz 3MB 2 / 4 N/A 650 / 1100MHz 35W

The T parts run at even lower base frequencies and have lower max turbo frequencies. As a result, these parts have even lower TDPs (35W and 45W).

I suspect the S and T SKUs will be mostly used by OEMs to keep power down. Despite the confusion, I like the flexibility here. Presumably there will be a price premium for these lower wattage parts.

A New Architecture
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  • chizow - Saturday, August 28, 2010 - link

    OK it seems as if you were referring to the PCIe lanes connected off the actual P67 chipset, not the native PCIe controller integrated into the CPU. I do recall the P55 chipset supporting PCIe 2.0 but limiting it to PCIe 1.0 bandwidth for interconnects like USB or SATA controllers.
  • chizow - Saturday, August 28, 2010 - link

    Overall it looks like Sandy Bridge is a disappointment. One really has to question why Intel has reversed their Tick Tock cadence this time around by launching their low-mid range parts and platform so soon on the heals of P55/Lynnfield/Clarkfield, but I guess it makes more sense in the light of the fact Intel delayed that platform's launch for nearly a year. I would be EXTREMELY disappointed if I bought a P55 board in the last year only to find out Intel is again requiring a platform/socket change for what appears to be a marginal upgrade.

    There's also some clear deficiencies and disappointments in terms of improvements over last-gen platforms with P67:

    1) No additional L2/L3 cache, in some cases less than previous gen.
    2) No native USB 3.0 support. One can conjure up myriad reasons for why Intel is resisting USB 3.0 adoption, but its clearly obvious at this point that they have been resisting it since its inception.
    3) Limited SATA 6G support. 2/8 ports I believe, but still better than nothing I suppose.
    4) No additional PCIe lanes or PCIe 3.0 support, but at least they're finally going to support their actual PCIe 2.0 rated specs?
    5) Limited/reduced overclockability. Big mistake imo, Intel seems to be forgetting why AMD was the enthusiast's choice back in the early Athlon/P4 days.

    That leaves us with the major improvements:

    1) 5-15% improvement clock-for-clock and core-for-core compared to older Nehalem and Westmere architectures.
    2) Lower TDP
    3) 2x faster GPU that's still too slow for any meaningful gaming

    Hopefully the high-end X58 replacement platform offers bigger improvements. There's also some question as to whether LGA2011 will be HPC/server only and an intermediary platform (LGA1355) is to replace LGA1366, however, early rumors show it will introduce or improve upon many of the deficiencies I listed with P67 and show us what Sandy Bridge is really capable of. Get rid of that extraneous, massive GPU on the high-end and replace it with more L3 and execution units and we'll see some bigger gains than the underwhelming 5-15% we see with this first version of Sandy Bridge.
  • seapeople - Saturday, August 28, 2010 - link

    Remember, that 5-15% clock-for-clock increase includes turboboost functioning on the current processors, which generally ratchets up the clock speed even in heavily multithreaded loads. It looks like the IPC increase with Sandy Bridge is at least 20% here. I would consider that fairly significant considering that Intel is already on top of the market with no real competition, other than for AMD to sell its top-of-the-line CPU's for cheap.

    It's also weird to see people deride IGP improvements that double the performance of the previous version. These integrated graphics are sufficient for probably 85% of the market (pretty much everyone who doesn't need to play current high-end games). Basically, the majority of people will be getting a free $50 graphics card built in to their processor, which itself is giving you a 20-40% performance improvement over a similarly priced last-gen processor.
  • chizow - Saturday, August 28, 2010 - link

    Yeah I actually factored Turbo Boost not working on Sandy Bridge, as otherwise it would probably be closer to 0-10% increase clock-for-clock. Anand pegs SB ~10% faster overall clock-for-clock in his conclusion with another 3-7% with Turbo.

    Also, tempering any excitement over that 10% IPC increase we have the very bad news about Intel limiting overclocking significantly, so for virtually anyone who already owns a P55/Lynnfield/Clarkfield combo anything but a "K" designated chip may actually be a downgrade as you won't be able to easily enable your own homebrewed "Turbo" any longer with most Sandy Bridge SKUs. I'd say the nearly guaranteed 30-40% OC you lose far outweighs the prospective 10-15% clock-for-clock gain you'd see with Sandy Bridge.

    As for the IGP being sufficient or any great accomplishment with what Sandy Bridge brings...I'd disagree. Sure I guess its great news for Intel that SB is actually able to adequately accelerate 1080p, but its still far from replacing even mid-range parts from 2-3 generations ago. If Anand perhaps ran some benchmarks at resolutions and settings people actually used it might be more relevant but the fact of the matter is, ~80% of "gamers" are gaming at resolutions of 1280x1024 or higher according to Steam Survey: http://store.steampowered.com/hwsurvey/

    My issue with the IGP is its going to take up significant die space, I estimate at least as much die area for the 2C IGP relative to the rest of the 4C CPU using Clarkdale as a guideline. For those who have no interest in an IGP or go with the P67 platform that doesn't even support it, that's a waste of die space that you're still absorbing and paying for.

    I just find it amazingly ironic how times have changed where the CPU was once thought of as the "general purpose" ASIC and the GPU was the "fixed-function", inflexible ASIC. How times have changed. With Sandy Bridge, we now have the CPU, an on-die IGP, and now even talk of an integrated super-sekret hardware video transcoder! Roles have clearly reversed as the CPU becomes ever-increasingly segmented and specialized while the GPU continues to evolve toward general purpose flexibility.

    In that sense, I really think AMD has the right approach with Fusion, as their ALU and FPUs will be shared on their Bulldozer and Bobcat designs rather than segregated and specialized like on Sandy Bridge with its single-purposed CPU cores and IGP EUs.
  • DanNeely - Sunday, August 29, 2010 - link

    80% of steam users is not the same thing as 80% of total PC buyers, or even 80% of the total gamers (think facebook games, etc). Serious gamers are not, any more than overclockers, a core market for Intel or AMD's CPU divisions.
  • chizow - Sunday, August 29, 2010 - link

    Yes I'm well aware Steam users do not make up 100% of the total PC market, but I would say it is a fair representation of the kind of hardware and resolution actual gamers use. In those same browser-based games you're referring to, any existing IGP would have been adequate but that's clearly not the market Intel is trying to entice or the point of the comparison, buyers who would otherwise choose discrete GPUs.

    As you can see, most of these users are not using Intel IGPs (only 7%) because they are inadequate for actual gaming at the resolutions ~80% of them game at, 1280x1024 or higher, so benching a bunch of games at 1024x768 and trying to pass off this new IGP as adequate tells me nothing as its not indicative of real world applications.

    Also, I'd take this a step further and argue the vast majority of those buying one of these new Sandy Bridge processors and systems would opt for a much higher resolution than even 1280x1024, as the most common desktop resolutions available for purchase today are going to be wide aspect 1680x1050, 1920x1080, and 1920x1200 displays. When's the last time you were able to buy an OEM build with a 1024x768 native display or even a 4:3 or 5:4 display for that matter?

    If Intel and AT want to pass this IGP off as an HD gaming solution to rival discrete solutions, bench some resolutions and settings people would actually expect to game at.
  • tatertot - Sunday, August 29, 2010 - link

    No, the 10% average outperformance in this review (see the conclusion) is against the i7 880 which has been allowed to turbo.

    Anand uses "clock-for-clock" to distinguish that part from the "same price replacement" the i5 760.

    So it achieves 10% average outperformance against a part that runs ~20% faster on single-threaded loads, ~15% faster on 2 threads... down to a bin or so of turboing on fully-threaded loads.

    That puts the clock/clock performance improvement at around 20%, and this is not including AVX / hardware transcoding.
  • chizow - Sunday, August 29, 2010 - link

    Yes the i7 880 is the basis for the clock-for-clock comparisons to come to 10% increase, with Turbo on SB he expects another 3-7% increase which is again, in-line with my estimate of 5-15% instead of 0-10% gain, clock-for-clock with and without Turbo.

    From the conclusion verbatim:
    "Sandy Bridge seems to offer a 10% increase in performance. Keep in mind that this analysis was done without a functional turbo mode, so the shipping Sandy Bridge CPUs should be even quicker. I'd estimate you can add another 3 - 7% to these numbers for the final chips."

    In almost all of the benches in the test, you are going to be limited to 1 or 2 Turbo bins max which is why Anand limited his estimates to 3-7%, because all of the tests will be using more than 1 core. Under the same tests the benefits of Turbo for both Lynnfield and SB are going to be the same assuming the final Turbo bins and throttling is also the same. So if Lynnfield only gets 1 bin at 2+ cores then SB would only get the same benefit, which is where I'm sure Anand based his estimates (100/3100 and 200/3100).

    Simply put, a 15% or even 20% clock-for-clock increase after 2 years from a new architecture is underwhelming imo, especially considering everything else they've left out, but I guess this is what we've come to expect and be thrilled about in a market dominated by Intel without any real competition. Sorry, I'm just less than impressed, especially given the artificial restrictions Intel plans to place on overclocking, further reducing any IPC benefits from SB compared to Lynnfield.
  • seapeople - Sunday, August 29, 2010 - link

    If you throw out Netburst, which was a significant decrease in IPC from Pentium III, when have we had significantly greater than 20% IPC increase within 2 years for an architecture? I understand your other complaints (although I don't see what's wrong with just buying the K models, which all indications suggest won't be much more expensive), but what were you really expecting in IPC increases? 40%? 60%?
  • chizow - Sunday, August 29, 2010 - link

    Netburst was a reduction in IPC but a tripling of clockspeed compared to P3, but surely you aren't forgetting the incredible gains in IPC from Netburst to Yonah (Core) and Conroe (Core 2)?

    Conroe effectively increased performance 100% clock-for-clock from P4 (or 50% or so from Yonah), as it offered some 50% better performance at 50% lower clockspeeds compared to Netburst. While I certainly don't expect that kind of revolutionary product every 2-3 years, we're not even close to that kind of gain in the 4-5 years since Conroe was introduced with not even that much aggregrate difference from Conroe/Penryn/Nehalem/Westmere to SB. From Conroe to SB, clock for clock, we're maybe looking at 50% improvement?

    That's 2 full Tick-Tock cycles signaling Moore's Law is clearly dead to Intel when it comes to performance, they only loosely follow its cadence in terms of refreshes, die sizes, transistor counts and fab processes. In order to achieve those kinds of gains, they had to redesign their CPU from nearly the ground-up to compete with AMD, which had the performance lead at the time. Intel clearly hasn't felt the need to improve or innovate signfificantly since then as AMD is essentially 2 generations behind still in performance, about on par with their Penryn offerings at this point.

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