Intel Pentium Extreme Edition 955: 65-nm uncovered December 27, 2005 Chris Crazipper Angelini

Introduction

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It might be a stretch to say that Intel has been looking for a magic bullet of its own. However, after a long and drawn-out performance battle with AMD, the chip giant must be growing weary of losing market share both on the desktop and in the server space.

Nowhere is AMD’s prominence felt more strongly than games, though. Single-core, dual-core, it doesn’t matter. The AMD64 architecture consistently asserts itself as an efficient design well-suited when it comes time to play. The latest dual-core and Hyper-Threading patches for Quake 4 and Call of Duty 2 demonstrate that Intel is still very much a contender, but it’ll take even more to overcome the deficit incurred by NetBurst.

As it turns out, Intel is actually planning to phase its controversial architecture out in 2006. All indications (that’d be roadmaps straight from Intel) point to the latter half of the year, meaning its existing layout, ushered in by the Prescott core, will persist until then. There will be one final stopping-off point on the road to inevitability—a sudden shift from 90nm manufacturing to an advanced 65nm process.

Now, we’re not looking for a magic bullet here. The architecture is what it is and it’d be silly to expect some revolutionary shift in dominance due to smaller transistors. Advanced lithography allows Intel to improve power consumption, reduce costs by manufacturing more workable cores per wafer, and add features. Fortunately, in this age of dual-core processing, the goodness is spread around doubly.

Presler is Born

The first core to benefit from 65nm is the dual-core Presler, aimed squarely at desktop customers. It combines a lot of existing technology with a bit of new, yielding a noteworthy boost in speed and functionality, but nothing particularly revolutionary.

Presler is an effective replacement for Smithfield, the core currently powering dual-core Pentium D processors. Whereas Smithfield consisted of one large die and two conjoined cores, the Presler package is made of up two separate dies, which is how Intel is able to achieve better operating yield this time around. The 65nm shrink also made it possible to include more cache memory. So while Smithfield wielded two attached cores each with 1MB of memory, Presler levels physically divided cores sporting 2MB each.

New Pentiums

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The Extreme Edition 955

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Heat

Adding cache and extra functionality is all well and good, but it doesn’t come free. The extra transistors (Intel is citing 376 million for Presler) push the Extreme Edition 955’s thermal design power up to 130W. Whether a function of increased thermal density or just a hotter chip, we initially ran into some instability issues that would cause lower benchmark numbers at first, and eventually a series of crashes at various points during testing.

The problem manifested itself every time we applied thermal grease to our reference cooling solution and reseated the heatsink. Apparently, the cooler wasn’t dissipating heat quickly enough on our open-air test bed. Only after attaching an unused reference heatsink with the original thermal pad were we able to get things running smoothly. Three heatsinks later, we’re still wondering why the chip seems to behave somewhat erratically, especially considering that it overclocked very well once firmly covered by a thermal pad.

Presler Redux

The 65nm Presler core powers several other Pentiums as well, all of which will bear the familiar Pentium D moniker. Those will be interesting chips because they’ll be noticeably different from this high-end specimen, shedding the 1,066 MHz bus and Hyper-Threading. Planned frequencies range from 3.4 GHz down to 2.8 GHz at a more conservative 800 MHz bus.

While a larger L2 cache will undoubtedly help the 65nm Pentium Ds outperform existing Smithfield-based offerings, it would have been even better to see the manufacturing advancement usher in some additional frequency or at least carry the accelerated bus speed across a wider range of products. C’est la vie—at least they will all sport lower price tags.

975X, Pricing, and Compatibility

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Enter A New Chipset

Other than the augmented power circuitry, there’s not much to differentiate 975X from the 955X chipset other than a more flexible PCI Express lane configuration. The 955X divided connectivity into one x16 slot and another x4. Intel’s 975X is able to split the lanes evenly into two x8s, ideal for running multiple graphics cards or supporting other high-speed peripherals in a workstation environment.

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Pricing

Intel expects the Pentium Extreme Edition 955 to be available mid-way through January at a $999 price tag. Curious thing—Extreme Edition processors commonly sell for more, not less, than Intel’s suggested retail price. Moreover, we’re also expecting more competition from another processor manufacturer by then too, which will really put some heat under these new 65nm chips.

Compatibility and Overclocking

The D975XBX motherboard—Intel’s reference design—is a fantastic piece of kit, with all of the trimmings to be expected from a workstation-class, enthusiast-oriented board. We did run into some issues with it, though. Even with a production BIOS, our single-core 3.46 GHz and 3.4 GHz Extreme Edition samples simply wouldn’t boot up.

Still, the board is a definite improvement over some of Intel’s past offerings. It proved robust enough to accommodate our overclocking efforts, which consisted of getting Windows up and running at 4.26GHz with default voltages. There’s definite headroom in the 65nm process. We can only hope Intel will push the process further before doing away with NetBurst altogether.

System Setup

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System Setup

Intel Pentium Extreme Edition 955 (3.46 GHz)
Intel Pentium Extreme Edition 840 (3.2 GHz)
Intel Pentium D 840 3.2 GHz)
AMD Athlon 64 FX-57 (2.8 GHz)
AMD Athlon 64 X2 4800+ (2.4 GHz)
AMD Athlon 64 4000+ (2.4 GHz)

Intel D975XBX 975X Express Motherboard
ASUS A8N32-SLI Deluxe Motherboard

1GB OCZ Technology DDR-400 CAS 2 Memory (2x512MB)
1GB Corsair DDR2-675 CAS 3 Memory (2x512MB)

NVIDIA GeForce 7800 GTX with ForceWare 81.98

Western Digital Raptor 34GB 10,000RPM Hard Drive

Windows XP Professional with Service Pack 2

DirectX 9.0c

Desktop resolution 1024x768, 32-bit color, 85Hz refresh

All power saving options were turned off, as were the Automatic Update and System Restore services. Graphics options under the ‘Performance’ tab were all disabled for maximum performance.

In an effort to represent the virtues of multi-core processing while still testing the latest games, we’ve mixed media encoding tests, synthetic metrics, and a handful of shooters.

Benchmarks

Windows Media Encoder 9
DivX Converter 6.1
3DMark05
PCMark05
F.E.A.R.
Half-Life 2
Quake 4
Far Cry

Windows Media Encoder 9

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Microsoft Windows Media Encoder 9

Notes

If there’s one genre where Intel really shows well, media-based apps would have to be it. Windows Media Encoder shows the dual-core Pentium processors generally outclassing AMD’s single-core offerings. But the Athlon 64 X2 4800+ turns around and takes a commanding first-place finish despite it all.

If anything, this test just shows how much better a multi-core chip runs in a test properly optimized to utilize it, regardless of your brand allegiance.

Dual-Core and DivX

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DivX Converter 6.1

Notes

There’s a new version of DivX available and it’s properly written to exploit dual-core and Hyper-Threaded processors according to the company’s documentation. The benchmarks would seem to tell a somewhat different story though, as we encoded an 833MB VOB file using high-def converter settings.

Surprisingly, the single-core Athlon 64 FX-57 took first place, followed by today’s star, the Pentium Extreme Edition 955. The dual-core X2 4800+, a favorite over any single-core offering, clinched a third-place finish.

3DMark05

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Futuremark 3DMark05

Notes

3DMark is a tough benchmark to judge. It’s a synthetic metric, to begin, which means individual game tests aren’t necessarily representative of the modern gaming landscape. Moreover, CPU results are derived from a software renderer designed to stress computational horsepower.

The situation is complicated further when results don’t jive. For example, the first few game tests seem to favor AMD, with scores on the FX, X2, and vanilla models all outstripping the latest Pentiums. But once you look toward dedicated CPU testing, Intel’s lineup suddenly rises to the surface, with the lowest 3.2 GHz Pentium D besting AMD’s Athlon 64 X2 4800+. Strange, isn’t it?

PCMark05

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Futuremark PCMark05

Notes

PCMark05 employs a lot of multi-tasking and indeed seems to benefit from the four-thread capabilities of Intel’s dual-core Extreme Edition chips. Even the vanilla Pentium D model is able to put some distance on AMD’s flagship.

Meanwhile, the dual-core Athlon 64 X2 4800+ has little difficulty outpacing its single-core equivalent. Clearly, that’s a test written with threading in mind and the single-core Athlon 64s just don’t do as well.

F.E.A.R.

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F.E.A.R.

Notes

Nearly all games are still optimized for single-threaded operation and F.E.A.R. is no exception. The best performance at 1024x768 comes from AMD’s familiar Athlon 64 FX-57, which speeds past the X2 4800+.

The new Extreme Edition 955 is a significant improvement over the 3.2 GHz model it replaces, but there’s not enough performance gain to catch AMD’s Athlon 64 4000+. Granted, everything evens out by 1600x1200, where all of the contestants score 29 and 30 frames per second across the board.

Quake 4

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Quake 4: What a Difference a Patch Makes

Half-Life 2

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Valve Half-Life 2

Far Cry

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Far Cry

Conclusion

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That’s not to say the release isn’t exciting. Faster frequencies, two large 2MB caches, the return of a 1,066 MHz front side bus, and Intel Virtualization Technology are but a few of the reasons affluent gamers will want to at least give this setup a look. The performance gains are very real, as they should be given this chip’s price. And if you’re solely comparing the Pentium Extreme Edition 840, Presler is unquestionably the better core.

Unfortunately, chances are good that any gamer who has purchased a processor in the last couple of years is already cruising with Socket 939 hardware. In that case, it’d be hard to endorse the Extreme Edition 955. Given AMD’s current strength, it continues to hold an advantage in a majority of games. And knowing what else will be available by the time this Extreme Edition 955 actually ships, we’d recommend holding off on a final decision until then.

The real excitement is bound for later in 2006, when NetBurst is displaced altogether by a more efficient architecture emphasizing performance per watt. The 65nm process should be even more mature by that point, boding well for whatever transition Intel hopes to make moving forward. Until then, it’d be best to check out Intel’s less expensive wares, including the low-cost Pentium Ds and upcoming 65nm, single-core Cedar Mill chips, which should expose lots of the same functionality at a much lower price point. The good news on those options is that they’re supported by many existing motherboards.

So while 65nm may not be a magic bullet for Intel’s performance woes, it’s a solid step forward in advancing the company’s future plans. We’re happy to see dual-core evolve once again here with Presler, but more excited about what we’ll see in a year’s time.