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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  • hmcindie - Monday, January 3, 2011 - link

    Why is that Quick Sync has better scaling? Very evident in the Dark Knight police car image as all the other versions have definite scaling artifacts on the car.

    Scaling is something that should be very easy. Why is there so big a difference? Are these programs just made to market new stuff and no-one really uses them because they suck? So big scaling differences between codepaths make no sense.
  • JarredWalton - Monday, January 3, 2011 - link

    It looks to me like some of the encodes have a sharpening effect applied, which is either good (makes text legible) or bad (aliasing effects) depending on your perspective. I'm quite happy overall with the slightly blurrier QS encodes, especially considering the speed.
  • xxxxxl - Monday, January 3, 2011 - link

    I've been so looking forward to SB...only to hear that H67 cant overclock CPU?!?!?!?!
  • digarda - Monday, January 3, 2011 - link

    Who needs the IGP for a tuned-up desktop PC anyway? Some for sure, but I see the main advantages of the SB GPU for business laptop users. As the charts show, for desktop PC enthusiasts, the GPU is still woefully slow, being blown away even by the (low-end) Radeon 5570. For this reason, I can't help feeling that the vast majority of overclockers will still want to have discrete graphics.

    I would have preferred to dual core (4-thread) models to have (say) 32 shaders, instead of the 6 or 12 being currently offered. At 32nm, there's probably enough silicon real estate to do it. I guess Intel simply didn't want the quad core processors to have a lower graphics performance than the dual core ones (sigh).

    Pity that the socket 2011 processors (without a GPU) are apparently not going to arrive for nearly a year (Q4 2011). I had previously thought the schedule was Q3 2011. Hopefully, AMD's Bulldozer-based CPUs will be around (or at least imminent) by then, forcing intel to lower the prices for its high-end parts. On the other hand, time to go - looks like I'm starting to dream again...
  • Exodite - Monday, January 3, 2011 - link

    Using myself as an example showing the drawback of limiting overclocking on H67 would be the lack of a good selection of overclocking-friendly micro-ATX boards due to most, if not all, of those being H67.

    Granted, that's not Intel's fault.

    It's just that I have no need for more than one PCIe x16 slot and 3 SATA (DVD, HDD, SSD). I don't need PCI, FDD, PS2, SER, PAR or floppy connectors at all.

    Which ideally means I'd prefer a rather basic P67 design in micro-ATX format but those are, currently, in short supply.

    The perfect motherboard, for me, would probably be a P67 micro-ATX design with the mandatory x8/x8 Crossfire support, one x1 and one x4 slot, front panel connector for USB 3, dual gigabit LAN and the base audio and SATA port options.


    Anyone? :)
  • geofelt - Monday, January 3, 2011 - link

    The only P67 based micro-ATX motherboard I have found to date is the
    Asus P8P67-M pro. (or evo?)

    Any others?
  • Rick83 - Monday, January 3, 2011 - link

    There's also a non-pro P8P67-M.

    Keep in mind though, that the over-clocking issue may not be as bad as pointed out. There are H67 boards being marketed for over-clocking ability and manuals showing how to adjust the multiplier for CPUs... I'm not yet convinced over-clocking will be disabled on H67.
  • smilingcrow - Monday, January 3, 2011 - link

    Major bummer as I was going to order a Gigabyte H67 board and an i5-2500K but am put off now. They seem to over-clock so well and with low power consumption that it seemed the perfect platform for me…
    I don’t mind paying the small premium for the K editions but being forced to use a P67 and lose the graphics and have difficulty finding a mATX P67 board seems crazy!

    I wonder if this limit is set in the chipset or it can be changed with a BIOS update?
  • DanNeely - Monday, January 3, 2011 - link

    Quick Sync only works if the IGP is in use (may be fixable via drivers later); for anyone who cares about video encoding performance that makes the IGP a major feature.
  • mariush - Monday, January 3, 2011 - link

    On the Dark Knight test...

    Looking at the Intel software encoding and the AMD encoding, it looks like the AMD is more washed out overall, which makes me think there's actually something related to colorspaces or color space conversion involved....

    Are you guys sure there's no PC/TV mixup there with the luminance or ATI using the color matrix for SD content on HD content or something like that?

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