Here comes our Intel Core i7 3770K review

Here is our review of the Core i7-3770K processor, Intel’s highest-end Ivy Bridge-based processor. There’s a lot to be discussed about it, but we’ll start from the top.


Sandy Bridge exits the scene

Sandy Bridge was a tock in Intel’s design and manufacturing tick-tock strategy. A ‘tock’ is usually a new architecture on a mature process and, as such, normally results in better yields and much better revenues for the manufacturer. Ivy Bridge, its successor, is a tick. It’s a new process on a slightly tweaked architecture so carries with it a risk of lower yields.

Sandy Bridge was a successful move for Intel, in particular in the processor graphics department. The 32nm-built processor fully integrated the graphics core and improved GPU performance over its stepdad, Clarkdale. It introduced an extended instruction set named AVX, video hardware encoding features and an optimized branch prediction amongst other improvements. The now-famous K-series offered unlocked multipliers and some serious overclocking headroom, which proved to be an enthusiast’s delight. It has proved to be a very successful design and was bound to be hard for Intel to do better.

As Sandy Bridge bows out of the market, you’ll see boxes and boxes at heavily discounted prices right now. The brutal slashing began a week before the launch, emptying shelves and making room for the shiny new toy to come. 


Ivy Bridge arrives, not late, not early

Lo and behold, the Ivy Bridge, Intel’s 3rd generation Intel Core processor with processor graphics (as the chipmaker calls it). Not really late to the party, nor early, just on time considering it is Intel that’s pushing the market forward. Despite rumours of delays and a bit of crossed lines between some Intel execs, the CPUs officially launched this Monday.

As of now, Intel is introducing 14 new Ivy Bridge-based SKUs. These include one mobile extreme edition, four standard mobile versions, five desktop and four low-power ones. In order, these are:

Core i7-3920XM, Core i7-3820QM, Core i7-3720QM, Core i7-3612QM, Core i7-3610QM, Core i7-3770K, Core i7-3570K, Core i5-3570K, Core i5-3550, Core i5-3450, Core i7-3770T, Core i7-3770S, Core i5-3550S and the Core i5-3450S.

The 3 prefix in the numbering is the generation, ie: 3rd generation Core processors, while the rest of the number represents the model itself. The letter suffixes represent variants. K for multiplier unlocked, S models are low power and T models are ultra-low power. You can see below the full spec sheets.


Intel Ivy Bridge desktop CPUs

Low Power Ivy Bridge CPUs

Mobile Ivy Bridge CPUs

Some facts about Ivy Bridge

Ivy Bridge is the successor to Intel’s Sandy Bridge microarchitecture. It isn’t a completely new design, but a spin on its predecessor, built on a smaller process and introducing a few new tweaks to the original recipe… some of them more than just pure performance tweaks. Still, we need to state some facts about Ivy Bridge, even before we start the testing. There are two parts to the Ivy Bridge architecture that need focusing on.

First of all, Intel proudly parades Ivy Bridge as the first 22nm “3D” (ie: tri-gate) transistor-based processor. Yes, 3D is all the rage even on CPUs. Simply put this means it’s stacking the gates on its transistors keeping current leakage down (allowing Intel to scale its CPUs to 22nm and beyond) as well as providing some valuable space savings. Transistors built on this 22nm process also require less power, which has amounted to some substantial power savings on the CPUs.

Ivy Bridge integrates a more advanced graphics core onto the die, the HD 4000, a DirectX 11 (ie: hardware tessellation), DirectCompute capable part, which now shares the CPUs own L3 cache. The Intel HD 4000 processor graphics features 16 Execution Units (let’s call them shaders), Clear Video Technology (to offload video decode) and Quick Sync Video, which is hardware based encoding and decoding, which, we’ll see, works quite well. Intel claims up to twice the performance of the graphics in its Sandy Bridge predecessor.

Ivy Bridge is a 1.4 billion transistor processor with a die size of just 160mm2, by comparison, Sandy Bridge had 1.16 billion transistors and a die size of 216mm2. Despite a higher transistor count, the more efficient power design of the 22nm “3D transistors” still rack up the power savings from 95W on the 2700K to 77W on the 3770K. You can see the “processor graphics” die area has become considerably larger than its predecessor

Sandy Bridge Die, labeled

Ivy Bridge die, labeled

Sandy Bridge (on top) and Ivy Bridge (below), you can see that the processor graphics element has swollen up considerably in the latter.

The new architecture comes hand in hand with a new chipset family, the 7 series, codenamed Panther Point. This chipset is compatible with both Sandy Bridge and Ivy Bridge, but not first generation Core products.

Intel supplied a DZ77GA-70K motherboard which is powered by the Z77 chipset and was launched a week prior to the Ivy Bridge release. The DZ77GA-70K, as most Intel motherboards, have all the shiny LEDs and the looks of a deadly killer, but is very tame when it comes to overclocking and basically stepping out of bounds, even though its EFI BIOS is one of the best we’ve seen to date. From system monitoring to dialing up the clock on the CPU, it’s all dead simple. Our overclocking experiments with the motherboard yielded a humble 1.4GHz overclock (3.5 to 4.9GHz), that we are sure was too easy to achieve, yet too hard to overtake on this particular motherboard – something Asus or Gigabyte will pick up and take to the next level. Still the EFI BIOS is gorgeous and simple to use.

The 7-series chipset includes Intel Rapid Storage Technology 11, USB 3.0, Thunderbolt support, SATA 3.0, PCIe 3.0 and up to 3 independent displays (depending on configuration). It’s what the 6-series could have been, in essence.

7 Series Chipset Overview



Our Engineering Sample Core i7 3770K is the counterpart to Intel’s Core i7 2700K Sandy Bridge, both clocked at 3.5GHz and both sport four cores / eight threads. Both have the same Turbo Boost speed of 3.9GHz and both are in the lab for our Apples to Apples comparison. Intel promised something in the vicinity of 7/15 percent pure CPU performance increase, and almost twice as much in “media” processing, thanks to its new graphics core, so let’s see what we get.

We’ll begin with a few CPU benchmarks. We aren’t holding our breaths on this, to be fair, Ivy Bridge didn’t introduce any revolutionary new magic tricks.

Cinebench R11.5 score

In Cinebench R11.5, the HD 4000 GPU is clearly marking the difference. The 3770K pulls ahead of its predecessor by a comfy margin.

Passmark Int/FPU score

Passmark is a simple fire’n’forget benchmark that assesses PC performance on several levels. We’ve focused on FPU and Integer performance. The Ivy Bridge FPU is tremendously more efficient than its predecessor, beating it by a 67 percent margin. Overclocked, the 3770K scales very well.

PCMark7 Computation score

The PC Mark 7 benchmark suite tests all PC subsystems, but we’re actually interested in the Computation score, here. Ivy Bridge and Sandy Bridge are almost 1-for-1.

POV-Ray Biscuit

POV-Ray is a ray tracing benchmark that relies on CPU muscle to render its target image.

SuperPI score

Purely mathematical in nature, Super PI maxes out single-threaded performance to calculate PI, in this case to the 2 millionth place.

SANDRA 2010 AES 256 bandwidth

The 3770K features a new encryption engine that allows it to squeeze a lot more data down the pipe.

SANDRA 2010 Arithmetic score

WinRAR Compression 320MB time

WinRAR Compression shows the minor edge the 3770K offers over the Core i7 2700K. A bit meh, if you ask us.

Now onto some strictly graphics-oriented benchmarks.

The HD 4000 end of business warrants its own analysis. With its 16 Execution Units and CPU-shared LLC (Last Level Cache) the HD 4000 is now spelling out some doom and gloom for the low-end discrete graphics business.

3DMark Vantage score

The inevitable 3DMark Vantage benchmark shows off DirectX 10 performance for the HD 4000 graphics. Granted it’s nothing to write home about, but it seems Intel is finally getting somewhere with its graphics processors.

3DMark 11 Performance score

3DMark 11 performance is nothing to sneeze at, considering that DirectX 11 support is brand new to the Intel lineup. We did get some artifacts in some scenes, but we believe this to be a driver issue, more than the hardware getting uncomfortable with the benchmark.

Dirt 3

We put Dirt 3 at max settings and Intel’s processor graphics survived the ordeal. If you scale down AA, you can game quite well on Intel’s new toy.

Metro 2033

We threw Metro 2033 at it as a crash test. The Metro 2033 – Frontline benchmark, running in DX 11 mode with Very High details, was like a slide-fest at times, but, again, scale back the details and image quality just a little bit and you’ll find something playable.

ComputeMark score

Considering Intel’s HD 4000 is now a OpenCL/DirectCompute capable part, we ran ComputeMark on it. The HD4000 part scored a quarter of the discrete competition.

TechARP x264 Benchmark

Finally, our media encoding test is where Intel’s HD graphics part stretches its legs. The HD 4000 graphics with its new media encoding engine chews away at frames almost as well as a discrete part.



Overall the Ivy Bridge core offers some meager performance gains over Sandy Bridge, good power savings and some great potential if you like to overclock your CPUs. The Core i7 3770K’s direct competition hails not from AMD (it hasn’t for a while now) but from its direct predecessor, the Core i7 2700K.

Over the next weeks you’ll also see that Ivy Bridge brought with it a bevy of new hardware releases, from motherboards to RAM to SSDs, as one way or another you do get quite unique advantages if you buy hardware that has been optimised for Intel hardware. The optimisations, however, revolve mostly around the motherboard and its chipset rather than the CPU, so if you see Z77 bundles with Core i7 2600K processors at a good price, you might want to consider the deal. As much as HD 4000 graphics are an improvement over their Sandy Bridge predecessor, many will keep on asking why bother with processor graphics in the mid-to-high end of things, considering most discrete GPUs will simply annihilate it. Ivy Bridge does bring DX 11 compute capabilities which we can only expect Intel will leverage down the line. Our media encoding results with the HD 4000 were close to the results we had with a discrete (GTX 460 1GB) GPU, which is nothing short of amazing. Gaming, while it might not be its forte, is definitely on the menu. Add to that the fact that you can combine the processor graphics with a discrete part, it’s up to Intel to bring to the fore some additional features.

Sandy Bridge was, admittedly, a hard act to follow, but Ivy Bridge is more than a speed bump with minor architectural improvements. It’s an important shift in design and manufacturing for Intel. In its own right, Ivy Bridge is a formidable opponent even for some higher-end Extreme Edition CPUs. It happens to also have a great deal of potential for forthcoming software and driver updates, like OpenCL/DirectCompute support. “Potential” is the operative word here, and it might not shake you to your core (no pun intended) and make you rush out to buy it.

If you can do without the power savings, overclocking tweaks and processor graphics, you might be better off picking up a Core i7 2600K/2700K on sale, but if you were about to buy one, this supersedes – dollar for dollar – what the 2700K had on offer, on just about every level. If you already own a Core i7 2600K or 2700K, you needn’t go digging in your pocket for the upgrade money just yet.