Intel never quite reached 4GHz with the Pentium 4. Despite being on a dedicated quest for gigahertz the company stopped short and the best we ever got was 3.8GHz. Within a year the clock (no pun intended) was reset and we were all running Core 2 Duos at under 3GHz. With each subsequent generation Intel inched those clock speeds higher, but preferred to gain performance through efficiency rather than frequency.

Today, Intel quietly finishes what it started nearly a decade ago. When running a single threaded application, the Core i7-2600K will power gate three of its four cores and turbo the fourth core as high as 3.8GHz. Even with two cores active, the 32nm chip can run them both up to 3.7GHz. The only thing keeping us from 4GHz is a lack of competition to be honest. Relying on single-click motherboard auto-overclocking alone, the 2600K is easily at 4.4GHz. For those of you who want more, 4.6-4.8GHz is within reason. All on air, without any exotic cooling.


Unlike Lynnfield, Sandy Bridge isn’t just about turbo (although Sandy Bridge’s turbo modes are quite awesome). Architecturally it’s the biggest change we’ve seen since Conroe, although looking at a high level block diagram you wouldn’t be able to tell. Architecture width hasn’t changed, but internally SNB features a complete redesign of the Out of Order execution engine, a more efficient front end (courtesy of the decoded µop cache) and a very high bandwidth ring bus. The L3 cache is also lower and the memory controller is much faster. I’ve gone through the architectural improvements in detail here. The end result is better performance all around. For the same money as you would’ve spent last year, you can expect anywhere from 10-50% more performance in existing applications and games from Sandy Bridge.

I mentioned Lynnfield because the performance mainstream quad-core segment hasn’t seen an update from Intel since its introduction in 2009. Sandy Bridge is here to fix that. The architecture will be available, at least initially, in both dual and quad-core flavors for mobile and desktop (our full look at mobile Sandy Bridge is here). By the end of the year we’ll have a six core version as well for the high-end desktop market, not to mention countless Xeon branded SKUs for servers.

The quad-core desktop Sandy Bridge die clocks in at 995 million transistors. We’ll have to wait for Ivy Bridge to break a billion in the mainstream. Encompassed within that transistor count are 114 million transistors dedicated to what Intel now calls Processor Graphics. Internally it’s referred to as the Gen 6.0 Processor Graphics Controller or GT for short. This is a DX10 graphics core that shares little in common with its predecessor. Like the SNB CPU architecture, the GT core architecture has been revamped and optimized to increase IPC. As we mentioned in our Sandy Bridge Preview article, Intel’s new integrated graphics is enough to make $40-$50 discrete GPUs redundant. For the first time since the i740, Intel is taking 3D graphics performance seriously.

CPU Specification Comparison
CPU Manufacturing Process Cores Transistor Count Die Size
AMD Thuban 6C 45nm 6 904M 346mm2
AMD Deneb 4C 45nm 4 758M 258mm2
Intel Gulftown 6C 32nm 6 1.17B 240mm2
Intel Nehalem/Bloomfield 4C 45nm 4 731M 263mm2
Intel Sandy Bridge 4C 32nm 4 995M 216mm2
Intel Lynnfield 4C 45nm 4 774M 296mm2
Intel Clarkdale 2C 32nm 2 384M 81mm2
Intel Sandy Bridge 2C (GT1) 32nm 2 504M 131mm2
Intel Sandy Bridge 2C (GT2) 32nm 2 624M 149mm2

It’s not all about hardware either. Game testing and driver validation actually has real money behind it at Intel. We’ll see how this progresses over time, but graphics at Intel today very different than it has ever been.

Despite the heavy spending on an on-die GPU, the focus of Sandy Bridge is still improving CPU performance: each core requires 55 million transistors. A complete quad-core Sandy Bridge die measures 216mm2, only 2mm2 larger than the old Core 2 Quad 9000 series (but much, much faster).

As a concession to advancements in GPU computing rather than build SNB’s GPU into a general purpose compute monster Intel outfitted the chip with a small amount of fixed function hardware to enable hardware video transcoding. The marketing folks at Intel call this Quick Sync technology. And for the first time I’ll say that the marketing name doesn’t do the technology justice: Quick Sync puts all previous attempts at GPU accelerated video transcoding to shame. It’s that fast.

There’s also the overclocking controversy. Sandy Bridge is all about integration and thus the clock generator has been moved off of the motherboard and on to the chipset, where its frequency is almost completely locked. BCLK overclocking is dead. Thankfully for some of the chips we care about, Intel will offer fully unlocked versions for the enthusiast community. And these are likely the ones you’ll want to buy. Here’s a preview of what’s to come:

The lower end chips are fully locked. We had difficulty recommending most of the Clarkdale lineup and I wouldn’t be surprised if we have that same problem going forward at the very low-end of the SNB family. AMD will be free to compete for marketshare down there just as it is today.

With the CPU comes a new platform as well. In order to maintain its healthy profit margins Intel breaks backwards compatibility (and thus avoids validation) with existing LGA-1156 motherboards, Sandy Bridge requires a new LGA-1155 motherboard equipped with a 6-series chipset. You can re-use your old heatsinks however.

Clarkdale (left) vs. Sandy Bridge (right)

The new chipset brings 6Gbps SATA support (2 ports) but still no native USB 3.0. That’ll be a 2012 thing it seems.

The Lineup
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  • iwodo - Monday, January 3, 2011 - link

    1. Transcoding @ 100fps is not uber fast. x264 ultrafast setting is even faster then that. So i hope there are further improvement or potentials in the Quick Sync that we haven't yet discovered.

    2. OpenCL - No mention of OpenCL? At all?

    3. I would think Intel GD has done very well this time around. And there are possibly 20 - 30% more performance to squeeze out given how Intel Gfx Drivers tend to be VERY POOR.
  • cactusdog - Monday, January 3, 2011 - link

    Thanks for the excellent run down of Sandy Bridge. As i have a x58 system i'm going to skip it and see what happens in Q4 . X58 has been a good platform and lasted longer than most others in recent years.
  • xxxxxl - Monday, January 3, 2011 - link

    I've thought it over...and i don't believe that H67 only support GPU overclocking.
    Like what others said, buy a "K" cpu to get HD3000 graphic and cannot overclock...and on the other side, those with P67 buy unlocked "K" CPU get HD3000 but cannot use...then what's the point of making HD3000 graphics?
  • strikeback03 - Tuesday, January 4, 2011 - link

    As they pointed out, with the Z series motherboard you can have both. That said, it does seem stupid that Intel would launch with those official guidelines, and in these comments others are saying some H67 motherboards are allowing the CPU multiplier to be changed.
  • rs2 - Monday, January 3, 2011 - link

    As tempting is this chip looks, my 3.8 GHz Core 2 Quad is still more CPU than I can really use most of the time. I wonder if we're reaching the point where improved compute performance is not really necessary for mainstream and even most enthusiast users.

    In any case, the upcoming 6-core/12-thread variant sounds interesting. Maybe I'll upgrade to that if Intel doesn't assign it to the $999 price point.
  • romanovskis - Monday, January 3, 2011 - link

    same here. For gaming or multimedia use, core2quad (mine at 4GHz) is still enough, and probably will be enough for 1-2 years. Best value/money is still in GPU upgrades.
  • iwodo - Monday, January 3, 2011 - link

    Beat Value / Money is SSD...
  • cgeorgescu - Monday, January 3, 2011 - link

    Best Value/Money is Beer, everybody knows that. Not 6-core but 6-pack.
  • karlostomy - Thursday, January 6, 2011 - link

    WIN ^^^
  • agr8man - Monday, January 3, 2011 - link

    a great review from you guys, and imo, the i5 2500k is really a steal.

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