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Mobile Gaming: Can Core i7-2920XM Beat Desktop Core i7-980X?
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1. So, You Thought Notebooks Were Weak?

Industry analysts have predicted the demise of the desktop PC almost every year since notebooks first started shipping with color screens. But extra room for power and cooling continues to push desktop performance at least two steps ahead of notebook counterparts. That performance disparity keeps a slowly-shrinking enthusiast PC market alive, even as improved notebooks all but consume other segments.

Enthusiasts alone can’t sustain the large manufacturing infrastructure left over from the desktop’s heyday, and we watch in despair as component firms either die or change targets. As we continue pushing new blood into the desktop market's veins, Intel is driving nails into its coffin with an architecture that delivers very compelling speed on a power budget.

Enthusiasts could view the company's so-called “second-generation Core architecture” as a performance upgrade or a compatibility killer, but reduced power consumption appears to be the real reason behind a broad range of evolutionary changes beyond Intel's Nehalem-based CPUs. The architecture's vastly-improved HD Graphics 3000, for example, isn’t designed to thrill value-seekers as much as to encourage them not to use power-hungry discrete cards, with its related Quick Sync function disabled whenever another GPU is added. Desktop buyers even have to pay a premium to get the full feature set in the form of a K-series processor, while notebook customers can take it for granted, since all mobile Sandy Bridge chips include 12 execution units.

The result of Intel’s efficiency push is a notebook processor that, with its high IPC and GPU-related killer app, could push everyone but gamers towards its notebook portfolio. Yet, that same ultra-efficient design and power-friendly thermals may combine to create a notebook CPU that can take on Intel's best desktop rival in games. The Core i7-2920XM can ramp up to a super-high 3.50 GHz under load, thanks to a wide range of Turbo Boost multipliers.

Of course the i7-980X has six cores (rather than four) and a 100 MHz higher Turbo Boosted frequency. But those are just the complications needed to make this an interesting comparison.

2. Test Settings
Test System Configuration
New Mobile CPUIntel Core i7-2920XM: Four Cores, Hyper-Threading, 2.5-3.5 GHz
8 MB L3 Cache, FCPGA988
Legacy Mobile CPUIntel Core i7-940XM: Four Cores, Hyper-Threading, 2.13-3.33 GHz
8 MB L3 Cache, PGA988
Desktop CPUIntel Core i7-980X: Six Cores, Hyper-Threading, 3.33-3.60 GHz
12 MB L3 Cache, LGA 1366
RAMDDR3-1333 CAS 9-9-9-24 Multi-Channel 4 GB DIMMs
12 GB Triple Channel (-980X), 8 GB Dual Channel (-940XM, -2920XM)
GeForce GTX 480MNvidia GeForce GTX 480M 2 GB
425 MHz GPU Core, GDDR5-2400
Mobile Driver Version 257.07
GeForce GTX 470MNvidia GeForce GTX 470M 1.5 GB
535 MHz GPU Core, GDDR5-3000
Mobile Driver Version 266.35
Radeon HD 6970MAMD Radeon HD 6970M 2 GB
680 MHz GPU Core, GDDR5-3600
Mobile Driver Version 8.810.0
SoundIntegrated HD Audio
NetworkIntegrated Gigabit Networking
Software
OSMicrosoft Windows 7 Ultimate 64-bit
ChipsetIntel INF 9.2.0.1019


Going beyond the basic desktop-to-notebook CPU comparison, we wanted to see how much better (if at all) the new mobile part is compared to its predecessor. That’s not easy to do, since we no longer have a Core i7-940XM to compare. Instead, the Core i7-940XM with GeForce GTX 480M graphics gets compared to a Core i7-980X with the same GPU, while a Core i7-980X with Radeon HD 6970M graphics gets compared to a Core i7-2920XM armed with the same GPU. Phew!

Benchmark Configuration
3D Games
Call Of Duty: Modern Warfare 2Campaign, Act III, Second Sun (45 sec. FRAPS)
Test Set 1: Highest Settings, No AA
Test Set 2: Highest Settings, 4x AA
CrysisPatch 1.2.1, DirectX 10, 64-bit executable, benchmark tool
Test Set 1: High Quality, No AA
Test Set 2: Very High Quality, 4x AA
DiRT 2Run with -benchmark example_benchmark.xml
Test Set 1: High Quality Preset, No AA
Test Set 2: Ultra Quality Preset, 4x AA
S.T.A.L.K.E.R.: Call Of PripyatCall Of Pripyat Benchmark version
Test Set 1: High Preset, DX11 EFDL, No AA
Test Set 2: Ultra Preset, DX11 EFDL, 4x MSAA
Audio/Video Encoding
iTunesVersion:9.0.2.25 x64
Audio CD (Terminator II SE), 53 min
Default format AAC
HandBrake 0.9.4Version 0.9.4, convert first .vob file from The Last Samurai (1 GB) to .mp4, High Profile
TMPGEnc 4.0 XPressVersion: 4.7.3.292
Import File: Terminator 2 SE DVD (5 Minutes)
Resolution: 720x576 (PAL) 16:9
DivX Codec 6.9.1Encoding mode: Insane Quality
Enhanced multithreading enabled using SSE4
Quarter-pixel search
Xvid 1.2.2Display encoding status = off
MainConcept Reference 1.6.1MPEG-2 to MPEG-4 (H.264), MainConcept H.264/AVC Codec, 28 sec HDTV 1920x1080 (MPEG-2), Audio: MPEG-2 (44.1 KHz, 2 Channel, 16-Bit, 224 Kb/s), Mode: PAL (25 FPS)
Productivity
Adobe Photoshop CS4Version: 11.0 x64, Filter 15.7 MB TIF Image
Radial Blur, Shape Blur, Median, Polar Coordinates
Autodesk 3ds Max 2010Version: 11.0 x64, Rendering Dragon Image at 1920x1080 (HDTV)
WinRAR 3.90Version x64 3.90, Dictionary = 4,096 KB, Benchmark: THG-Workload (334 MB)
7-ZipVersion 4.65: Format=Zip, Compression=Ultra, Method=Deflate, Dictionary Size=32 KB, Word Size=128, Threads=8
Benchmark: THG-Workload (334 MB)
Synthetic Benchmarks and Settings
3DMark VantageVersion: 1.0.2, GPU and CPU scores
PCMark VantageVersion: 1.0.1.0 x64, System, Productivity, Hard Disk Drive benchmarks
SiSoftware Sandra 2011Version 2011.1.17.25, CPU Test = CPU Arithmetic / MultiMedia, Memory Test = Bandwidth Benchmark
3. Benchmark Results: SiSoftware Sandra CPU

We wanted to run a couple of “CPU-only” benchmarks to show why the Core i7-980X is still considered top dog in the desktop market, given its six cores and Hyper-Threading technology enabling twelve threads.

The desktop Core i7-980X stands nearly 50% higher in Sandra Arithmetic compared to the mobile Core i7-2920XM, thanks to its greater number of cores. Proving the advancement in mobile CPU technology, Core i7-2920XM beats its flagship mobile predecessor by a similar amount.

Likewise, Sandra Multimedia shows that the Core i7-980X’s 50% greater number of cores gives it an approximate 50% performance lead. In spite of that loss, the old mobile CPU looks like a chump compared to the Core i7-2920XM.

Most applications do not yet use more than four cores, so we expect the difference in real-world applications to be far smaller. Since this is particularly true of games, the Core i7-2920XM still has a chance to prove itself there. But first, we must get those pesky application benchmarks out of our way.

4. Benchmark Results: Audio And Video Encoding

The new Core i7-2920XM starts out with a bang in iTunes, likely due to its improved architecture. This encoder doesn’t even acknowledge the Core i7-980X’s extra cores, so we're seeing competition on the basis of IPC and clock rate alone.

HandBrake is multi-core-optimized, putting the six-core -980X in a far lead.

It’s still not 50% faster than the new notebook processor, however, and most of the credit for its mere 22% lead can again be given to the Core i7-2920XM’s revised architecture.

DivX takes the power of all six Core i7-980X cores and runs with it, while Xvid prefers the slightly higher IPC of the Core i7-2920XM. The formerly-high-end Core i7-940XM is beginning to look like a budget part.

MainConcept gets a 32% boost from the desktop processor’s extra cores, while the new mobile CPU trumps the old one by a far more significant 41%.

5. Benchmark Results: Productivity

The desktop Core i7-980X beats the mobile i7-2920XM by nearly 40% in Photoshop, while the -2920XM outpaces the -940XM by a similar amount. The desktop-processor’s extra cores play a big role here, but no reason could possibly be adequate for the i7-940XM’s big loss.

The 3ds Max benchmark being used here doesn’t appear to fully benefit from the Core i7-980X’s extra cores, but we're already using a newer version in our launch stories, and that one will appear more widely from now on.

WinRAR plays a little nicer with the Core i7-940XM, but the chart still places the i7-2920XM in the middle.

Is it time to recycle last-year’s high-end notebooks? The Core i7-2920XM quad-core continues its strong showing, placing marginally behind the six-core i7-980X.

6. Benchmark Results: 3DMark Vantage

Because the i7-940XM notebook was returned before we could attempt to upgrade its graphics card, our 3D performance discussions will be limited to the Core i7-980X versus i7-2920XM. We included statistics from a similar-vintage Core i7-980X plus GeForce GTX 480M configuration to assist anyone who wants to try figuring out where the i7-940XM might place in today’s charts.

Differences that shrink as resolution is increased usually represent a CPU bottleneck. Let’s see how 3DMark rates each GPU on its own.

The Core i7-2920XM comes out ahead of the equally-configured Core i7-980X in 3DMark’s GPU score. But let’s see where its CPU places.

Unlike most games, 3DMark rewards additional CPU cores with higher performance numbers.

7. Benchmark Results: Call Of Duty: Modern Warfare 2

Our most recent Call of Duty benchmark favors the Core i7-2920XM over the i7-980X by a statistically significant amount, though in reality, the difference would go unnoticed at such high FPS for all configurations.

Enabling anti-aliasing knocks every system down a notch. Yet, all of them run so smoothly that most players would be hard-pressed to tell the difference.

8. Benchmark Results: Crysis

Remembering that the Core i7-980X has a higher peak clock in addition to its higher core count, we’re slightly surprised to see the mobile Core i7-2920XM pushing better numbers in Crysis.

Architectural optimizations can help explain the Core i7-2920XM’s continued dominance in Crysis through our highest test settings.

9. Benchmark Results: DiRT 2

With two gaming wins already under the mobile Core i7-2920XM’s belt, we were a little surprised to see the desktop Core i7-980X take a large lead in DiRT 2. Perhaps the game is optimized for threading, or maybe the larger L3 cache is positively affecting performance.

Increased detail levels shift a larger portion of the load to the GPU, and the Core i7-2920XM again passes the i7-980X. One architectural enhancement present on both notebook CPUs (as well as LGA 1155- and 1156-based desktop CPUs) is an onboard PCI Express controller, and its win at these GPU-bottlenecked settings most likely results from reduced PCIe latency.

10. Benchmark Results: S.T.A.L.K.E.R.: Call Of Pripyat

The Call of Pripyat benchmark starts off with a small lead in favor of the mobile Core i7-2920XM. Once again, our less demanding tests tend to place a little more emphasis on CPU performance, and it’s apparent that this title is limited to four or less cores.

With the load shifted to GPU performance, it’s hard to tell the difference between top desktop and notebook solutions. The Core i7-980X slightly edges out the i7-2920XM when equipped with the GeForce GTX 470, but loses to it when paired with the Radeon HD 6970M with all differences falling within the a margin of error.

11. Power And Efficiency

Though we’ve seen overall performance improvement from Intel’s Sandy Bridge architecture, power consumption was the reason we wanted to put this mobile flagship through its paces. Desktop uses might not care as much, but any power savings can pay big returns in battery life and notebook noise.

The Core i7-2920XM appears to save a little energy compared to the Core i7-940XM, but an exact analysis is impossible without getting the older system back for new tests with a newer graphics card. Enough data exists for us to notice that the Core i7-980X (with Nvidia's GeForce GTX 480M) used 69% more idle power and 75% more load power than the i7-940XM, and that that the same-model Core i7-980X (with GeForce GTX 470M graphics) consumed 170% more idle power and 134% more load power than the Core i7-2920XM.

Dividing average performance by average power makes the comparison much easier, because it shows that the graphics card accounts for only a few percent of the overall power-to-performance ratio. The mobile Core i7-940XM saved power by being a lesser performer, while the desktop i7-980X used most of the the extra power it consumed to produce big performance gains. The Core i7-2920XM mixes some top-performance scores with low-power numbers to prove itself more than 50% more-efficient than either its desktop or high-end-mobile predecessors.

12. Conclusion

So, can Intel’s latest high-end mobile processor really outperform its most-extreme desktop part in a gaming configuration? Let’s first take a look at what our CPU benchmarks showed.

While the Core i7-2920XM makes its extreme mobile predecessor look like a low-end part, the desktop CPU triumphs by a margin that’s almost as big. Yet, many of our applications were optimized for the desktop part's six-core architecture, while most games are not. So, let’s get to the heart of the matter.

A 1% lead in games for the i7-2920XM amounts to a performance and efficiency coup for the mobile processor, at least when both it and the Core i7-980X are paired with the Radeon HD 6970M. Our previous desktop tests have shown that PCIe performance has less impact on Nvidia graphics processors, so the i7-2920XM’s on-die PCIe controller could explain the small discrepancy between graphics brands.

Shortening the discussion to the question posed in today’s title: yes, the Core i7-2920XM can beat the Core i7-980X in mobile gaming. But desktop gaming enthusiasts need not fear the reaper quite yet, as we still haven’t found a notebook graphics solution capable of convincing Eyefinity or Surround performance.