If you look back at the battle between AMD and Intel you will see something that is both interesting and funny at the same time. This is a comical little irony that has been repeated over and over for more than a few years.  What is the ironic happening? Well it is where AMD dreams up an idea and talks about it openly only to have someone else bring the product to market. We saw this with the first Dual Core CPUs. Intel came out with the Pentium D on May 25th 2005. This was roughly two months before AMD released the First Athlon 64 X2 in August of 2005 [although the X2 was a massively superior CPU]. The same thing was again see when Intel beat AMD to the Quad Core punch by almost a year with Kenstfield [which ended up outperforming AMD?s native Quad Core]. Naturally, we can debate is this of sheer Intel’s engineering power, market position or just the fact that AMD has a permanent habit of roadmap slip-ups that started with the original K8 architecture.

Regardless of the reason, we see the same thing happening all over again. AMD has been talking of moving the GPU onto the CPU for a very long time, a strategy called Fusion. Originally, first Fusion products were supposed to show on the market in 2009 but that obviously didn’t happen. Unfortunately for AMD, they have yet to take the first steps towards that goal. Instead we see Intel taking that Idea and again bringing the first steps to market in the form of the Dual Core 32nm Clarkdale CPU. Let?s take a look at this interesting new CPU from Intel and see if it will be remembered like the Pentium-D or the Core 2 Quad.

What?s new
As with most new CPUs there are going to be new and exciting things that come with them. One of first that comes to mind with Clarkdale is the GPU being right on the CPU packaging. It is not on the CPU die [we have to wait for 2011 and 32nm Sandy Bridge architecture which taped out back in May 2009, a year ahead of AMD's Fusion APU, Ed.] but sits next to it. There are multiple reasons for this but the biggest is that the GPU is still at a 45nm process while the CPU core is 32nm. This GPU has also been beefed up from previous versions.


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Intel has added a hardware accelerated dual video decode for smoother HD playback, a new HD and SD sharpness and xvYCC [Extended Gamut YCC Color Space] Post Processing feature. The xvYCC feature is especially interesting as it pushes the color space beyond the traditional sRGB that most IGPs work with. This means cleaning and sharper colors for HD video playback and a better viewing experience.


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Of course xvYCC is not the end of the enhancements that the new GMA HD IGP has to offer.  You also can add Dual [and simultaneous] HDMI support, 12bpc [bpc - bits per channel] Bit Color Depth for both HDMI and DisplayPort, Audio for the DisplayPort and Dolby TrueHD and DTS-HD Master Audio.  All of these enhancements are aimed squarely at the HTPC enthusiast but seem to leave the gamers out in the cold.


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Next up on our list of new items is the move to the new 32nm process. This move means a reduction in power consumption and also allows for an increase in the number of transistors in the same area [or a more complex CPU without a larger Die].


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Other enhancements include the addition of AES-NI. AES-NI consists of six new instructions that help to combine some of the overhead associated with performing AES mathematical operations and speed up encryption and decryption.


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Clarkdale also brings with it some of the same features and technologies that the Nehalem architecture carries, like advanced smart cache, Hyper-Threading, Turbo Boost, and advanced power gating. The Clarkdale Core i5 661 uses these well to its advantage. Intel has given you all of this inside of an impressively low 87 Watt TDP [for the Core i5 661]. That includes both the CPU and the GPU.

Typical Intel: New CPU – New Chipset
One thing that Clarkdale brings that may hurt it is the need for a new chipset and motherboard to use this. While the Core i5 661 is still a Socket 1156 CPU you will only be able to use it with an H55, H57 or Q57 chipset. As each manufacturer will have their own implementations of this chipset so it is pointless to go into too much detail here but we will cover the basics of what each of these has to offer.


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The H55 is the entry level chipset for the Clarkdale CPUs. It brings along the Intel Flexible Display Interface [with HDMI, DVI, VGA, and DisplayPort], dual channel DDR3 memory support, HD Audio, and roughly the same features that a P55 chipset would offer. There is one notable exception; this is the lack of RAID support. Although there is nothing to prevent an OEM from dropping in RAID support, it will not be integrated into the chipset from Intel.


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The H57 is a little step up and brings an option for Intel Rapid Storage Technology [RAID] to the table. The Q57 is another step and in addition to RAID it offers an option for Intel Active Management technology.


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Overclocking
Overclocking a CPU is fun for the most part but each new design brings new challenges and Clarkdale is no exception. While we have a smaller process and it uses much less power we have another item thrown in that can put a monkey wrench into any overclocking plans. This new headache is the inclusion of the GPU on the CPU packaging. How will this inclusion affect the Core i5 6xx?s ability to overclock is a question that will concern many.  The problem has to do with the way that GPU component interacts with the CPU [and the heat the CPU generates] As you push the CPU the GPU sitting right next to it could potentially become power starved while it also absorbs more heat from the overclocked CPU.  While I have a feeling the GPU will be able to handle the heat, I do think that you will need to drop extra power into the GPU to maintain stable performance at high BCLCKs.  This means that if a manufacturer does not provide proper support for adding extra power to the GPU your overclocking could be very limited.

Fortunately for us we used the ASRock H55M Pro for our Clarkdale testing and good air cooling [not the box cooler]. This board offers up to a +200mv increase to the GPU and allowed us to reach 4.3GHz [24x172] using the IGP and 4.5GHz using an add-in board. This is not a bad overclock at all for what is really meant as an entry level/mainstream platform.

Overclocking with the Intel GMA HD

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Overclocking with an Add-in board (AMD Radeon HD 5870)
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Remember that the overclocking results shown here are not a definitive measure of how well a retail Clarkdale CPU will perform, and individual results will vary based on components you use. Still we can see the potential performance gains to be had with the 32nm Core i5 611 and the H55 chipset.

Test System and Comments
Processor
: Intel Core i5 661
Mainboard: ASRock H55 Deluxe [Supplied by ASRock]
Memory: 4GB Kingston KHX12800D3T1K3/6GX [Supplied by Kingston]
Hard Disk: Kingston SSD Now M [re-badged Intel X25-M 80GB SSD - Supplied by Kingston]
Graphics Card
: Zotac GTX 285 AMP! Edition 1GB [flashed to stock BIOS - Supplied by Zotac]
Cooling
: Cooler Master Hyper 212 [with an extra fan - Supplied by Cooler Master]
Operating System
: Microsoft Windows 7 Ultimate x64
Drivers
: Intel INF 9.1.1.1015, ForceWare 195.62

Processor: Intel Core i7 870, Intel Core i5 750
Mainboard
: ASRock P55 Deluxe with P130 BIOS [Supplied by ASRock]
Memory
: 4GB Kingston KHX12800D3T1K3/6GX [Supplied by Kingston]
Hard Disk: Kingston SSD Now M [re-badged Intel X25-M 80GB SSD - Supplied by Kingston]
Graphics Card
: Zotac GTX 285 AMP! Edition 1GB [flashed to stock BIOS - Supplied by Zotac]
Cooling: Cooler Master Hyper 212 [with an extra fan - Supplied by Cooler Master]
Operating System
: Microsoft Windows 7 Ultimate x64
Drivers: Intel INF 9.1.1.1015, ForceWare 195.62

Processor: Intel Core i7 975, Intel Core i7 965, Intel Core i7 920
Mainboard: ASRock X58 Extreme with P130 BIOS – Supplied by ASRock]
Memory
: 6GB Kingston KHX12800D3T1K3/6GX (Supplied by Kingston)
Hard Disk
: Kingston SSD Now M [re-badged Intel X25-M 80GB SSD - Supplied by Kingston]
Graphics Card: Zotac GTX 285 AMP! Edition 1GB [flashed to stock BIOS - Supplied by Zotac]
Cooling: Cooler Master Hyper 212 [with an extra fan - Supplied by Cooler Master]
Operating System: Microsoft Windows 7 Ultimate x64
Drivers: Intel INF 9.1.0.1007, ForceWare 195.62

Processor: AMD Phenom II X4 955 Black Edition
Mainboard: Asus M4A79T Deluxe with BIOS 1604 [Supplied by Asus]
Memory
: 4GB Kingston KHX12800D3T1K3/6GX [Supplied by Kingston]
Hard Disk
: Kingston SSD Now M [re-badged Intel X25-M 80GB SSD - Supplied by Kingston]
Graphics Card: Zotac GTX 285 AMP! Edition 1GB [flashed to stock BIOS - Supplied by Zotac]
Cooling
: Cooler Master Hyper 212 [with an extra fan - Supplied by Cooler Master]
Operating System: Microsoft Windows 7 Ultimate x64
Drivers
: AMD Driver Version 3.0.732.0, ForceWare 195.62

Comments
At first you may wonder why I chose to pit this dual core CPU against a bevy of Intel?s finest and a top performer from AMD. The reason is pretty simple; Clarkdale, in the form of the Core i5 661 represents an extension of the Nehalem architecture into the mainstream and entry level market. Intel is boasting that Clarkdale brings Nehalem performance and power to this market. To see if it truly does we need to see how close to the rest of the family the Core i5 can come. If it is able to hold its own with its bigger brothers then Intel has a real threat to AMD?s mainstream market penetration [especially if it can compete with one of AMD?s higher end native quads].  This showing will also indirectly indicate where it will stand against other dual core CPUs. We chose the ASRock H55M Pro for our testing of the Core i5 611 as it offers a good mix of features [including over-volting the GPU].


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Synthetics
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.

So for the numbers crowd; let?s get started with two of the industry standards for benchmarking system and gaming performance.

FutureMark – PCMark Vantage
PCMark Vantage is a suite of tests designed to give an easily reproducible result. It is also often used for bragging rights.


PCMark Vantage Testing
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Right out of the gate the Dual Core i5 661 manages an upset. Using only the GMA HD IGP it manages to outperform an AMD Phenom II X4 955 CPU by over 3000 point [the X4 955 was using an nVidia GTX 285] and when we add the GTX 285 to the i5 661 we see performance that tops the Core i5 750 Quad Core and an extended lead over the Phenom II X4 955.  

FutureMark – 3DMark Vantage
3DMark Vantage is the second in the twin tests from FutureMark.  This one turns to gaming. It is one of the first tests to use DX10 for the rendering loops. We also see the first full-scale usage of PhysX in a gaming test.


3DMark Testing, not so good for the GMA HD
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Here we have our first indication that the Core i5 661 is not combined with a true gaming GPU.  In our testing with 3DMark Vantage we see the IGP dragging the CPU score down due to processing overhead [and due to shared system memory]. When we overclocked to 4.3GHz we gained some of this back but not enough to get too happy. Even when combined with a GTX 285 the Core i5 661 comes in last place.

Sisoft Sandra 2010
Next up we have Sisoft?s Sandra up on the board. Here we see the numbers that represent the raw potential of our CPUs.


Sisoft’s Sandra 2010
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This somewhat confusing graph tells an interesting tale. We see that while the Core i5 661 is only a dual-core silicon with Hyper Threading, but it can still hang with the Quads.

Maxon Cinebench R10 x64
This test from Maxon [the makers of Cinema 4D] covers CPU based rendering. The test renders a single file using a single CPU and then again using all the available CPUs.


Cinebench R10 Render Testing
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Again we find that the Dual Core nature of the i5 661 is not much of a limiting factor as it shows excellent single core performance and even decent multi-core performance. Unfortunately it cannot completely keep up with the real quads but we still see good numbers here.

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 0.99b Number Crunching
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As we have come to find out when we tested the Lynnfield Core i5 750, Hyper Threading and HyperPi do not play well together. Still our hardy little Core i5 661 does manage to outpace the AMD Phenom II X4 955 by quite a nice margin.

Adobe Photoshop CS4
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.


Photoshop CS4 Performance
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The Dual Core i5 661 does an excellent job here. While there are some filters that have a greater impact its overall performance is better than the slower clocked Core i7 870 and Core i5 750 and the similarly clocked Phenom II X4 955.

Real World Benchmarks

LightWave 3D
Our first real world test is LightWave 3D. This is an industry standard 3D Animation and rendering software from Newtek. For our testing runs we chose a sample scene from the Lightwave 8 content file that is installed with the new 9.6 version. Out tests were of the Moonbase scene frame 32. Settings were 1080p resolution, 7-Pass PLD, Gaussian Sharp reconstruction filter, and 512MB segment memory.


LightWave 3D -x64 Rendering in the Real World
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In our real-world rendering tests we do see the Core i5 661 struggle but again this little dual core hangs in there and gives a good showing.

AutoGK 2.55
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% quality and record the time it takes to complete.


Video Transcoding with AutoGK 2.55
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Unfortunately the Core i5 661 fails at transcoding video formats. I am not saying that it cannot transcode video; the Core i5 661 can, it is just much slower than the other CPUs used in our group. Still, this task is very important to the mainstream user these days. It is a common thing to hear about people "ripping" DVDs and movies to play on their computer, iPhone/iPod or Zune. Sadly the Core i5 661 does not do this very well. It took almost an hour to transcode a 2 hour movie from DVD to a 100% quality AVI file. This was almost 15 minutes slower than the next closest CPU even overclocked it is still up to 5 minutes slower. This is undoubtedly due to it being a Dual Core Vs. a Quad. Truth to be told, native GPU transcoding would beat both Dual and Quad architectures.

Gaming
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.

Cryostatis: Sleep of Reason
Cryostasis is an interesting game. It combines heavy physics into a horror/survival game into a sub-zero environment.  You also have to take ?sprit journeys? to alter the past. If you change the past it affects your present. Settings used are shown below.


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UGH, that is the only word I can come up with to describe the gaming performance of the Core i5 661 and its IGP. Even at lower resolution [with all eye candy shut down] you can barely attain playable frame rates with this game.

FacCry 2
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.


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Although the Core i5 661 does a better job with FarCry 2 [and can achieve playable frame rates with a much higher frame rate] it still lags far behind the rest of the crowd.

Call of Duty: Modern Warfare 2
Modern Warfare 2 has received a lot of press this year. First for Infinity Ward?s decision to drop dedicated servers and then later for some of the numbers that were thrown around. Still no matter what the press; the game is a good game for testing DX9 gaming performance on the DX10 capable IGP built into the Core i5 661.


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Again we find the Core i5 661 is just not a gaming GPU; you simply have to reduce the resolution down too far and remove too much from the game to get playable frame rates.

Gaming recap
The Core i5 661 is just not good enough to bill as a gaming GPU. Even when you reduce the resolution it struggles to achieve playable frame rates. Of course I would say the same thing for 90% of the chipset based IGPs also. They just do not have the raw power to rendering today?s first person shooters, or even many of the real time strategy games. Still when you drop in an add-in card there is not noticeable affect from the IGP on the CPU. It seems to disappear, as does the poor performance. We also have to say that Intel is not pushing the Clarkdale as a hardcore gaming GPU. They do say that it covers mainstream and casual titles right out of the box though. I think what this means is that the GMA HD is capable of handling entry level gaming, but it is not meant for more demanding titles and certainly not the ones we typically use for testing.

Value
As of this writing Intel plans to release the Core i5 661 at a $196 price point. This is for 1000 unit lots, but should still give us a price around $200 for the CPU + GPU combo. When you consider the performance of the CPU [and the fact that many H55 and H57 board will retail for about $100] it is a great value. This is even if you need an add-in GPU to balance out your system.  Given the scalability of the 661 when overclocked this CPU could even find a home in many "entry-level" enthusiast systems.

Conclusion
So what do we think of the Clarkdale? Our experience with the Core i5 661 is very positive indeed. We saw great performance given the fact that the Core i5 661 is only a dual core CPU with Hyper-Threading to allow for four threads per execution cycle. It shows off the just how far Intel?s Nehalem architecture has come and the underlying power it contains. In five of our tests the i5 661 was able to keep pace with other true Quad Core CPUs and even outperform them.
Unfortunately the GPU stuffed inside is limited in its performance. It is amazing for HTPC and mainstream usage, but falls well short of the mark in terms of real gaming. But then again this is a common issue with internal graphics and not one that is limited to Intel and their GMA HD. As a counterpoint to this minor setback the i5 661 has a good price point and allows for you to drop an inexpensive GPU to take up that slack. With the reduction of prices for 57xx series cards and also the lower end 220 and 240GT cards from nVidia the failings of the internal GPU are not that big of a deal in the long term.
All in all Intel has fired off a great opening shot in the war of the 32nm CPU as well as the CPU+GPU war that is coming. AMD?s response needs to come soon and needs to be just as strong. Intel also must consider the possibility that nVidia may soon enter this market; especially if the FTC forces Intel to give nVidia an x86 license. If that happens then Intel may find themselves sitting with a great CPU saddled with an unused 45nm block of silicone and priced higher than it needs to be. But for now Intel will enjoy a lead with the 32nm Clarkdale in more than one category while their ties with the big OEMs like Dell, Gateway and Acer will get them market share and adoption.

For its performance, design and potential we are happy to award the Intel Core i5 661 CPU our Mainstream Innovation Award.