Hardware, Reviews

Review: Sandy Bridge Core 2011 processors from Intel

It is a New Year and time for a new CPU. We have been hearing about this one from Intel for quite a while now and it is time for us to see exactly what it has to offer in terms of performance and power.

Of course the CPU we are talking about it Sandy Bridge. This is a new CPU design along with a new Socket (1155 so you lose a pin). These CPUs are geared towards what they have identified as mega trends.

These are the same trends that we have told you about in the past, heavy video editing, transcoding, photo manipulation and gaming. We have been fortunate enough to get both a Core i7 2600K and a Core i5 2500K for testing. Let’s take a look and see what they can do.

What’s new?

As part of Intel’s "Tick Tock" the new Core i5 2500K and Core i7 2600K are a new design on a tested process. What does that mean? Well Intel typically moves to a new process or die shrink with an existing design (with some improvements) to help alleviate problems that could arise from trying to reduce transistor size AND build a new CPU. The first CPUs built on the 32nm process that Sandy Bridge will use were the Nehalem based Westmere CPUs. Again this was an extension of the Nehalem microarchitecture while Sandy Bridge is something new.

The first new item on the list (besides the 32nm process) is the inclusion of a GPU right inside the CPU die. This is not like the Clarkdale CPUs where the GPU was tacked onto the CPU packaging. Here we see the GPU as an integrated part of the CPU (it even shares the same cache as the CPU cores).

The new HD2000/3000 GPU is capable of supporting 3D Stereoscopic Blu-ray playback at 1080p over HDMI along with the usual HD audio. You also get DX10.1 (sorry no DX11 just yet) and Open GL 3.0 support and 3D gaming support.

The HD2000/3000 not only shares the cache of the CPU but also is directly connected to the CPU cores. This allows for much faster response and processing of data between the two components as well as fast access to the shared system memory. For those of you thinking about OpenCL and GPU processing we are not sure if you will be getting that at this stage. After all you do not get full OpenCL support until DX11.

That does not mean you are not getting some in hardware processing though. Looking things over is seems that Intel has made some significant changes to the way certain items are handled by the GPU. On the Clarkdale most of your video processing was done by software. With Sandy Bridge everything is moved into hardware. Intel calls this Quick Sync Video. This new GPU bound technology will be available in more than a few software titles this year.

Another new feature (and one we expect from new CPUs) is an improved power design. Intel has created a new power algorithm that allows them to combine the CPU, GPU and many functions of the Northbridge into a single monolithic die that still fits into a 95W TDP envelope (even less on the mobile CPUs). This new power algorithm is tied into the Trubo Boost 2.0 feature and can dynamically allocate power to both the CPU and GPU as needed.

This comes into play with single threaded applications that may be graphics intensive (like some older games) but does have a small drawback. If you remember with Clarkdale there were certain issues with overclocking if you were using the built-in graphics. This was due to the way the CPU allocated power between the two separate pieces (CPU and GPU). With Sandy Bridge the CPU and GPU are part of one monolithic die. They share cache and also power gates.

Because of this Intel has had to lock the power gates to the BCLK. This prevents almost all BLCK overclocking as any adjustment to the 100MHz BCLK can throw the power system into disarray. That does not mean you can’t overclock, it just means that you will have to stick with kicking up the multiplier instead of adjusting the internal BCLK. We will show you what we mean a little later in our overclocking section.

Next up on the "new" list is a new set of instructions called AVX or Advanced Vector Extension. This new set of instructions allows for "enhanced floating point intensive application performance" This is an extension of the existing x86 instruction set and pushes the SMID registers from 128 to 256-bits.

Additional features of this new set of instructions are the ability to combine two operands (instructions) to be combined into a three part group where the destination or outcome is a completely different register than exist in the original two instruction group.

For example if you have X:=X+Y AVX can change this to Q:=X+Y this maintains the integrity of the operands in the original two registers. This type of instruction is great for workloads that require intensive number crunching. It also happens to be great for multi-media and content creation. Both of which happen to be about number crunching when you boil everything else away.

There are other items that are in the new Sandy Bridge, things like a new socket. Moving from the 1156 to 1155 (because of the inclusion of the GPU). But when it all comes down to it Sandy Bridge is all about Multi-media. Whether it is watching a Blu-ray movie, encoding video for YouTube, or playing a game, Intel has built this new CPU with those features and market demands in mind even the new AVX instructions are aimed and content consumption and creation. Now it is up to us to see if it can live up to Intel’s claims.

The test system and overclocking

Playing with a new CPU is always fun. Especially when everything is different like it is with Sandy Bridge. We found that we could not rely on our old notions of overclocking or even trouble shooting in some cases. Thankfully the board we chose is not using the new BIOS layout that other are, it did make learning how to overclock again much easier in the long run. We also were happy to find that our existing 1156 coolers worked without a problem on the new 1155 boards. Here’s what our test system looked like:

  • Processor: Intel Core i7 2600K and Intel Core i5 2500K
  • Mainboard GIGABYTE P67A-UD7(Supplied by GIGABYTE)
  • Memory: 6GB Corsair CMT4GX3M2A2000C8 (Supplied by Corsair)
  • Hard Disk: Corsair Force F120 120GB SSD (Supplied by Corsair)
  • Graphics Card: Asus EAH5870 S.T.A.L.K.E.R (Supplied by Asus)
  • Cooling: Corsair H70 Water Cooling (Supplied by Corsair)
  • Operating System: Microsoft Windows 7 Ultimate x64
  • Drivers: Catalyst 10.12

Overclocking was a snap, all I really had to do was find a multiplier that would allow me to boot into the system and then push up the voltage until I had stability from there it was an interesting game of "leap frog" with voltages and multipliers. We ended up with a nice OC of 4.7GHz on both the Core i7 2600K and the Core i5 2500K these were both at 1.42V in the BIOS. Not bad at all really.


For our performance testing we like to have a combination of synthetic and real-world testing.  For Synthetics we have the usual bank of tests from FutureMark, Maxon, Sisoft, and HyperPi. These tests cover raw performance and potential. This side of testing brings out the basics of the CPU on its own while our real-world testing covers actual usage.

Memory Bandwidth

We have decided to throw this one in to illustrate a point. At one point in time AMD was the undisputed king of memory bandwidth. There was just no other CPU that could manage the same memory performance that AMD could. Then starting with the AM2 series something changed.

AMD dropped from being the king to just on par with Intel. Once Phenom came out that difference was even more obvious. Now with Phenom II we still see that type of poor memory bandwidth. This can only hurt the PII X6 as now there are six CPU cores that will be begging for work to do. So for the numbers crowd, let’s get started with two of the industry standards for benchmarking system and gaming performance.

These numbers are very good for this CPU and put it right up there at the top with even overclocked CPUs.

Other Sandra CPU Functions

Of course we would be remiss if we did not show you how the 875K performed the other CPU tests in Sandra. So we ran the usual gamut of benchmarks including the Crypto benchmark.

As you can see the 875K performs as it should at stock speeds but really shines when we push it a little.

FutureMark tests
PCMark Vantage

PCMark Vantage is a suite of tests designed to give an easily reproducible result. It is also often used for bragging rights. The suite combines some of the most common PC tasks into an easy to use format.

Here we find some excellent scores for the people that like the synthetic side of computer testing. This could be an indication of good things to come in our later real-world testing as well.

3DMark 11

3DMark 11 is the second in the twin tests from FutureMark.  This one turns to gaming. It is one of the first tests to use DX11 for the rendering loops. However, FutureMark moved away from the use of the proprietary PhysX and are using a much more brand neutral flavor. This test offers us a glimpse into how a CPU will perform with a discrete GPU dropped in.

It is hard to tell what if anything this means to the average user. The 3DMark scores appear to be right in line for the range of CPU and GPU we are testing here but we will need more data to give you a firm conclusion.

Cinebench R11.5

This test from Maxon improves threading efficiency (up to 64 threads) over the older R10 and also includes some advanced rendering techniques to keep the CPU working hard. CB R11.5 also includes a revamped OpenGL test for GPU performance.

Both of the new Sandy Bridge CPUs do very well here even if they are not at the top. We would still have liked to see some better performance here, but it was just not to be.

HyperPi 0.99

HyperPi is a great test to find out how well a CPU can handle large amounts of math based information. With HyperPi you have a single instance of SuperPi Mod 1.3 running on each logical and physical core. This puts a great deal of stress on the CPU and also on the internal memory controller.

HyperPi is tough on a CPU, it is even more tough on a CPU that has Hyper Threading. When that is on each Physical CPU core is trying to run dual instances of a Pi calculation out to 32 million places.  The fact that the HT enabled Core i7 2600K does so well is very impressive and leads us to think we might see some great performance in rendering and transcoding as well.

Photoshop CS5 tests

Photoshop is an industry standard image manipulation application. It is great for not only editing photographs but also for creating original content. For out testing here we used the Driverheavn Photoshop script. This is a custom built action that puts a stock image through a series of filters and allows you to record the time each takes to run.

Wow, look at those times! The stock Core i7 2600K is even faster than a Core i7 980X! Now that is what I call an improvement.

Real world tests
LightWave 3D 9.6 x64 tests

Our first real world test is LightWave 3D. This is an industry standard 3D Animation and rendering software from Newtek.  Our rendering tests with LightWave 9.6 have changed. I have always been a fan of the Classic Camera and the multi-pass PLD anti-aliasing that it offered. However, what I did not know was that this type of camera model was only capable of about 75-80 percent CPU utilization.

This makes it very inefficient (as I am sure you guessed) so we made the shift to the newer perspective camera and are using its much better (100 percent CPU utilization) threaded engine as well as a newer and more efficient form of
anti-aliasing. Along with this new camera model we get ray tracing and some other nice features.

We have also leapt from the 1080p resolutions we used before and are now setup with a 35mm 4k resolution of 4096 x 3072. This should give the CPU a nice workout. To show off the vast difference in performance between the two we ran both and show you the render times here. This also shows what you can do when your application is truly written for a multi-threaded CPU.

Looking at these numbers it is hard not to be impressed. They are simply excellent for the market range this CPU is aimed at.

AutoGK 2.55 tests

AutoGK is a compilation of transcoding applications wrapped up into a very nice installer and front end application. It is a great ‘one-stop’ for transcoding or even re-encoding files. For our testing we transcode a 2-hour movie at 100 percent quality and record the time it takes to complete.

No surprises here, the Sandy Bridge duo are simply fast.

Adobe Light Room 2.7 x64 RAW file conversion

This one has been requested more than once. We took 100 15.1 MP RAW files as shot by our Canon T1i camera and used Adobe’s Light Room 2.7 x64 to convert them to JPEG. We set the resolution to 1280×853 and the quality up to 75 percent but left everything else as shot. Then we timed how long it took the system to convert these files.  We ran the test three times and used the middle score for our results. The settings used are shown below.

Once again we find that the 2600 and 2500 are great performers. Interestingly though it is the overclocked 2500K that tops out our list.

After Effects CS5 tests

After Effects is an application that allows you to add 3d animation and rendered effects to still photography or to video that you import. It is very multi-thread aware and is also an excellent test for memory and HDD usage. We have a stock project that was provided to us by Peter Kapas.

Although these are the first two CPUs in our new After Effects testing the numbers here are very good for this project.

Gaming tests

Gaming is a very real-world test. We do not use benchmarking scripts but actually play the games though a pre-planned level and record the frame rates using FRAPS. This allows up to see exactly how the CPU benefits (or hinders) performance. We have moved to a new format and will now be bringing you a game of each of the three common Direct X Levels. This should give a broader idea of CPU performance across multiple gaming APIs.

Modern Warfare 2 DX9 tests

Call of Duty Modern Warfare 2 is a fast paced first person shooter style game. It covers the gamut of modern ‘low intensity’ and covert style combat that is actually going on in today’s world. Yes the plot line is farfetched but some of the actual types of missions are not far from the mark. As it is a console port it is limited to DX9 for its engine. However due to the massive ‘bar fight’ AI it can be a good test for a CPU. Settings are shown below.

FarCry 2 DX10 tests

FarcCry 2 is a large "sandbox" style game that does not have any real levels. It is all mission based but allows for a great deal of free movement in the environment. You take the role of a mercenary sent to kill "The Jackal" a dangerous gun runner. Unfortunately you are overcome by your malaria and end up serving as an errand boy for a local thug. Settings are show below.

Battlefield Bad Company 2 tests

This title from EA also is our first DX11 First Person Shooter. It is a game that is heavily multi-player oriented, but also has a short single player game. In that game you take the part of a World War II commando infiltrating a small island to recover a Japanese defector for the first level, after that things get more modern. Unfortunately, the pace does not pick up.  Settings are show below.

Gaming recap

OK, gaming is sort of up and down here. We see the two new CPUs do well in one game and not so well in the others. Still we cannot fault them as at the speeds these games are running you would be hard pressed to tell them apart. We can safely say that buying a Sandy Bridge CPU will not hinder your gaming at all.


The Intel Core i7 2600K will retail for $317 in 1,000 unit lots. This should put retail pricing at about $400 or so dollars. The Core i5 2500K will hit at $205 (in the same 1k lots) so retail should be around $300. Both of these prices are excellent for the performance we are seeing. When you consider that the 2600K can come close to the performance of Intel’s flagship 980X and even outperform it when the 2600K is overclocked, that is not something to thumb your nose at.

It will be a serious hit to AMD’s current best value for yo
ur money position in the market, especially considering the fact that both of these CPUs come complete with a GPU. While we have not had the chance to fully test out the GPU performance (that is for another article) what we have seen so far has been nothing short of impressive at the prices we are seeing.

Final thoughts

Sandy Bridge is a serious piece of silicon. It represents a new design and a new direction. It competes indirectly with AMD’s Fusion CPU but at a much higher level that Fusion can cover at this time. Our testing time with the Core i7 2600K and 2500K was very limited but we have a stack (literally) of both P67 and H67 boards waiting to flesh out the rest of the story. I have a feeling this one will be quite the happy ending for Intel and in many ways the consumer.

We are very impressed with the performance we have seen so far and cannot wait to dive into that ever growing stack of boards. Unfortunately that project will have to wait until after CES. For now we can assure you that Intel’s Sandy Bridge is one impressive CPU and one that, given its price, will have a big impact on the market.