Because HEXUS.net (the location of the reviews) is running so slowly, I though I would do everyone the favor of putting the reviews for the newly release Intel processors online here in full:
Introduction
Any reader with a passing interest in consumer-level CPUs will have noted that Intel has been planning to release a new range of desktop processors in mid-2006. Known to many by the codename given to the performance series, Intel's Conroe has been making waves since March of this year. We brought you initial benchmarks, which you can find
here (
warning: slow), and further numbers on our usual testing platform
here (
warning: slow).
Up until today, though, Intel didn't want many to talk about what made Conroe tick. However, with the pesky NDA out of the way, we can reveal how and why Intel is going to reclaim the performance crown it, arguably, lost to AMD since the inception of the Athlon 64 series, some 3 years ago.
We've taken a look at Intel's Core 2 Duo and Core 2 Extreme processors and pitted them against AMD's finest. Read on to see what you'll be buying this summer.
Overview
Intel's new Core 2 architecture builds on the foundations laid down by the Core micro-architecture which debuted on Intel's current range of dual-core mobile CPUs. Again, those unfamiliar to the new terminology may know them as Yonah.
Let's be clear about this. Intel, by moving away from NetBurst and the ultra-high clockspeeds required for the Pentium 4 series to be competitive against AMD's Athlon 64 series, has decided that a new micro-architecture was required that would provide both excellent performance and be energy-efficient, too. That, then, spelt an end to the Pentium 4 as Intel's consumer CPU of choice. It's still around, of course, but Core 2 Duo/Extreme is now positioned as Intel's performance CPU.
The following table details the range of Core 2-based CPUs Intel will be offering right off the bat, along with a Pentium Extreme Edition 965 and Athlon 64 FX-62 for reference. We'll then discuss the reasons behind why Core 2 is destined to give AMD a very hard time.
| Processor name | Intel Core 2 Duo E6300 | Intel Core 2 Duo E6400 | Intel Core 2 Duo E6600 | Intel Core 2 Duo E6700 |
| Form factor | LGA775 | LGA775 | LGA775 | LGA775 |
| Manufacturing process | 65nm | 65nm | 65nm | 65nm |
| Physical cores | 2 | 2 | 2 | 2 |
| Inst. per clock* | 4 | 4 | 4 | 4 |
| Pipeline stages | 14 | 14 | 14 | 14 |
| Clock speed | 1.83GHz | 2.13GHz | 2.40GHz | 2.67GHz |
| FSB | 266MHz (1066MHz QDR) | 266MHz (1066MHz QDR) | 266MHz (1066MHz QDR) | 266MHz (1066MHz QDR) |
| Memory support** | DDR2, 800MHz, DC | DDR2, 800MHz, DC | DDR2, 800MHz, DC) | DDR2, 800MHz, DC) |
| L1 cache total (per core) | 64KiB | 64KiB | 64KiB | 64KiB |
| L2 cache total | 2MiB | 2MiB | 4MiB | 4MiB |
| ISA | x86, x86-64, SSE-SSE4 | x86, x86-64, SSE-SSE4 | x86, x86-64, SSE-SSE4 | x86, x86-64, SSE-SSE4 |
| TDP | 65W | 65W | 65W | 65W |
| Operating voltage | 1.2-1.3625V | 1.2-1.3625V | 1.2-1.3625V | 1.2-1.3625V |
| Price | $183 | $224 | $316 | $530 |
Processor name |
Intel Core 2 Extreme X6800 |
Intel Pentium E.E 965 |
AMD Athlon 64 FX-62 (AM2) |
|---|
Form factor |
LGA775 |
LGA775 |
AM2 |
|---|
Manufacturing process |
65nm |
65nm |
90nm |
|---|
Physical cores |
2 |
2 |
2 |
|---|
Inst. per clock* |
4 |
3 |
3 |
|---|
Pipeline stages |
14 |
31 |
12 |
|---|
Clock speed |
2.93GHz |
3.73GHz |
2.8GHz |
|---|
FSB |
266MHz (1066MHz QDR) |
266MHz (1066MHz QDR) |
200MHz |
|---|
Memory support** |
DDR2, 800MHz, DC |
DDR2, 800MHz, DC |
DDR2, 800MHz, DC |
|---|
L1 cache total (per core) |
64KiB |
28KiB |
128KiB |
|---|
L2 cache total |
4MiB |
4MiB |
2MiB |
|---|
ISA |
x86, x86-64, SSE-SSE4 |
x86, x86-64, SSE-SSE3 |
x86, x86-64, SSE-SSE3 |
|---|
TDP |
75W |
130W |
125W |
|---|
Operating voltage |
1.2-1.3625V |
1.3-1.4V |
1.3-1.4V |
|---|
Price |
$999 |
$899 |
$999 |
|---|
A couple of things to note about the table. It doesn't necessary tell you why Core 2 Duo/Extreme is fast but it does highlight the fact that current models are only differentiated by clockspeed and L2 cache levels. Of course, faster speed grades inevitably bring along higher prices.
Models
Intel is initially launching Core 2 Duo at a starting speed-grade of 1.83GHz. This model, designated E6300, will be equipped with 2MiB of L2 cache and falls under the codename of Allendale. We expect Intel to release a lower-clocked version in the near future. Other than a lower clock speed and 2MiB L2 cache, the E6300 is, for all intents and purposes, architecturally identical to the rest of the Duo range; it's no Celeron model. That's especially gratifying with respect to its relatively low price.
The range is headlined by the Intel Core 2 Extreme X6800, which operates at 2.93GHz and, like Extreme Editions before, is multiplier-unlocked. Deep-walleted enthusiasts will have some fun with this one.
Let's digest the information above, particularly the architectural elements, with some insightful commentary.
Architecture analysis
Here's what makes the Core 2 Duo tick, folks.
Dual-core supportIntel Core 2 Duo-based CPUs will harness two execution cores based on a single piece of silicon. The cores communicate with the rest of the system via a
single bus, which will be clocked in at 1066MHz and offer around 8.5GB/s CPU-to-MCH bandwidth. Initial Core 2 Duo CPUs will be manufactured on Intel's proven 65nm process. Projections state that 45nm production will begin in Q2 2007. Core 2 Duo supports a 14-stage execution pipeline, down (read better) from the 31 present on the Prescott-based Pentium 4.
See, two cores. What would happen if Intel put another two on? Kentsfield, anyone?
CPUs will be packaged in the present LGA775 form factor, and most i975X chipset-based (CrossFire-compatible) motherboards that are manufactured post-April 2006 will support its differing power requirements. Intel is also launching a range of new chipsets, the P965-series, that will carry native Conroe support. We've got a couple of models in our labs. and we'll be bringing you benchmark results shortly. We'll also be seeing competing chipsets from the likes of ATI and NVIDIA in due course, with the latter offering Core 2 Duo support alongside SLI.
Wide Dynamic ExecutionCurrent x86 processors can deliver 3 instructions per clock cycle. Core 2 Duo, however, has been architected to fetch, dispatch, execute and retire up to four full instructions simultaneously, offering a 33% boost over, say, a Pentium 4 CPU. Allied to this, Core 2 Duo also supports what Intel terms Macro-Fusion, which can combine certain common x86 instructions (pairs, say, compare and conditional jump) into a single instruction (micro-op) for execution, thereby reducing overall processing time. Processing efficiency is the name of the game here.
Intel Smart Memory Access and Advanced Smart CacheHigher-end Core 2 Duo CPUs will be equipped with 4MiB of on-chip L2 cache, minimising the need to run back to system memory for frequently used data. Unlike the present Pentium 4 micro-architecture, Core 2 Duo's two cores will share the cache amongst each other. Intel's engineering team has found that forcing the cores to individually allocate and use cache is more efficient than allotting a fixed, per-core amount. By varying the amount of cache split over the two cores Intel hopes that cache misses, the bane of modern CPUs in terms of execution efficiency, will be further reduced.
Core 2 Duo also supports what Intel terms Smart Memory Access. Put simply, and falling under the banner of memory disambiguation, it's a form of out-of-order, built-in intelligence that predicts and loads the upcoming instruction data
before current store instructions have been processed. Intel has designed algorithms that can accurately predict whether a load can be processed before the store, thereby, again, potentially saving overall execution time.
Coupled with a heavily optimised cache, and thinking about it how it all fits together, the Core 2 Duo's memory access latency will be better than the present Pentium 4's, for the reasons discussed above. Intel has toyed with the idea of integrating a memory controller right on the CPU die itself, a la AMD, but reckons that Core 2 Duo's intelligent architecture masks latency well enough for it to do without. We'll put this assertion to the test in our ScienceMark 2.0 memory latency analysis.
Advanced Media BoostIncreasing efficiency with Streaming SIMD (Single Instruction Multiple Data) Extentions, Core 2 Duo CPUs are able to process a 128-bit instruction in a single clock cycle, rather than requiring the incumbent two clocks that current generations employ.
Intelligent Power CapabilityIntel has designed Core 2 Duo not only to perform well on a clock-for-clock basis but also to be energy-efficient whilst doing so. This is precisely where its mobile heritage shines through. Intelligent, which seems to be the watchword for Core 2 Duo, management monitors core usage and application requirements such that it can power-gate parts of the CPU when not in use; there's little need for two cores running at full power in single-threaded applications, for example. Intel reckons that it has improved the physical requirements of power-gating enough for it to offer better power consumption than previous generations'.
Intel indicates that all Core 2 Duo models (barring Extreme) will harness a 65W TDP; half that of the Pentium Extreme Edition 965 CPU. The Core 2 Duo Extreme, however, ships with a slightly higher 75W TDP.
Further, Conroe will ship with an integrated digital thermal sensor. The sensor is embedded on the die itself and will give more-accurate readings. Incidentally, the 965 Express chipset family supports Intel Quiet System Technology, which intelligently manages processor and system fan-speeds in relation to core temperature, ensuring the fan(s) are spun just fast enough to keep the processor from throttling.
SSE4, Virtualisation Technology, 64-bit processingKeeping the features list ticking over is support for SSE4, which adds a further 16 new instructions to the present SSE3 set, and, optimally, increases computational speed for SIMD-based execution. Virtualisation Technology offers hardware-isolated virtual partitions that allow the user to run multiple operating systems on one PC, and 64-bit processing (EMT64), along with Execute Disable Bit, is carried over from the Pentium 4 line of CPUs.
Overall thoughts
Intel's Core 2 Duo micro-architecture is the desktop arm of a multi-pronged assault. The mobile version, Merom, takes much of what makes Core 2 Duo good and adds in number of extra power-management features. Woodcrest, the codename for the current server- and workstation-based Intel Xeon DP5100-series, again takes the micro-architecture as a base, thereby completing a top-to-bottom family line-up. Intel's invested heavily in its Core (2) micro-architecture and it's now pervasive across platforms.
How does it look?
One's an engineering sample Core 2 Extreme X6800 and the other an E.E 965. Which is which?
A look at the back offers some clues. Core 2 Extreme is on the left on both pictures. They're both LGA 775 processors and the Core 2 Extreme magic is contained under the heatspreader.
| System | Intel LGA775 system | AMD AM2 system |
|---|
| Processor | Intel Core 2 Duo X6800 (2.93GHz, 4MiB L2 cache, LGA775)
Intel Core 2 Duo E6700 (2.67GHz, 4MiB L2 cache, LGA775)
Intel Core 2 Duo E6600 (2.40GHz, 4MiB L2 cache, LGA775)
Intel Core 2 Duo E6400 (2.13GHz, 2MiB L2 cache, LGA775)
Intel Pentium Extreme Edition 965 (3.73GHz, 4MiB L2 cache, LGA775) | AMD Athlon 64 FX-62 (2.8GHz, 2MiB L2 cache, AM2)
AMD Athlon 64 X2 4600+ (2.4GHz, 1MiB L2 cache, AM2) |
| Motherboard | Intel D975XBX Bad Axe rev. 304 | ATI Sturgeon Reference |
| Memory | 2GiB (2 x 1024) Corsair PC8500 |
| Memory timings and speed | 4-4-4-12 2T @ 800MHz (PC6400) |
| Graphics card(s) | Sapphire Radeon X1900 XTX 512MiB |
| Disk drive(s) | Maxtor 300GB SATA (6V300FO) | Seagate 160GB 7200.9 SATA 3Gbps |
| BIOS revision | 1304 (20/06/06) | 08.00.13 (04/05/06) |
| Mainboard software | Intel Inf Update 8.0.0.1009 | CATALYST 6.6 Southbridge package and SATA(AHCI): 2.5.1540.25 |
| Graphics driver | CATALYST 6.6 BETA |
| Operating System | Windows XP Pro SP2 32-bit |
|---|
Testing software
We ran the processors through our usual array of benchmarks
2D
- ScienceMark Memory Bandwidth
- ScienceMark Memory Latency
- HEXUS Pifast calculation to 10M places
- HEXUS Cryptography
- Realstorm Raytracing 2004
- KribiBench v1.1
- HEXUS WAV encoding
- HEXUS DivX encoding
- Cinebench 2003 v9.5
3D
- Far Cry v1.33
- Quake 4 v1.04
- Splinter Cell: Chaos Theory
- Futuremark 3DMark05 b1.2.0
We had no problems in running the Core 2-based CPUs in an Intel D975XBX 'Bad Axe' rev. 304 motherboard. Motherboard vendors are now adding Core 2 Duo support to their line of i975X boards. We're adamant that all the top tier guys have compliant boards. However, should you wish to jump on the 965-Express bandwagon, that's fine too.
Rather than give you all the treats at once, we'll wait a couple of days before showing you Core 2 Extreme X6800 performance on i975X vs P965.
We've added in all but one Core 2 Duo processor in our line-up here, and we've compared performance to the fastest Presler CPU around, the Pentium Extreme Edition 965. Further, we've added in benchmark results from AMD's Athlon 64 FX-62 and 4600+ CPUs, both run on a reference ATI Sturgeon AM2-supporting motherboard. This way, we feel, you'll better appreciate where each Core 2 Duo processor lies in relation to the competition.
On a heat-related note, using a reference LGA775 heatsink the Core 2 Extreme X6800 idled at 53C in BIOS and the 2MiB cache-equipped E6400 at 44C. Windows load temperatures were similar to these figures. Bear in mind that ambient temperature was 27C and no extra cooling, other than CPU fan, was directed towards the CPUs.
We'll be taking a look at overclocking a retail, off-the-shelf Core 2 Duo next week, rather than offer numbers from engineering samples, so stay tuned for that.
Anyway, on to the benchmarks.
Memory tests
According the results from ScienceMark 2.0, memory bandwidth is lower on the quartet of Core 2 Duos than on a Pentium Extreme Edition 965 (Presler core) and AMD's AM2 CPUs. The new Intel CPUs connect to the discrete MCH in the same manner as all previous LGA775 CPUs, so it's no surprise to see a sub-6GiB/s figure. Remember, they're being fed through an interconnect that operates at 8.5GiB/s.
Here's the first vindication of Intel's Smart Memory Access and Advanced Smart Cache technologies. Intel's engineers' remit was to reduce system memory access latency such that performance would be comparable to an on-die controller's. Deep buffering, high on-chip cache levels, and highly intelligent prefetching, which form part of the out-of-order superscalar Core 2 Duo micro-architecture, help reduce access time to sub-AMD Athlon 64 levels. Look at how comparatively slow the Pentium 4 architecture is in this regard.
Single-threaded tests
Our first single-threaded test, HEXUS Crypto, evaluates the relative FPU strength of the CPUs. In this case, the 2.93GHz-clocked Core 2 Extreme X6800 is just beaten out by an AMD Athlon 64 FX-62. It's worth noting that the midrange E6600 part, running at 2.4GHz, beats out the 3.73GHz Pentium Extreme Edition 965 CPU in this test.
Pifast, which calculates the constant to 10M places, relies on the CPUs' number-crunching and memory bandwidth ability. The reported numbers are correct, that is, a 2.13GHz Core 2 Duo (E6400), priced at around $220, leaves the Athlon 64 FX-62 trailing in its wake. It completely annihilates the time posted by the '965, too. Extreme performance is, well, extreme, posting the fastest time, by far, from a stock-clocked CPU.
The raytracing test shows us that the 'X6800 doubles, yes doubles, the performance laid down by Intel's other not-so-extreme processor. The range-topping FX-62 is the only other CPU not to succumb to Core 2 Duo defeat. So far, we've seen the Core 2 Duo E6400, a $220 processor, generally outperform the finest (and most expensive) CPU AMD has to offer.
Multi-threaded tests - media encoding
Intel and AMD have, by and large, been neck-and-neck in our WAV-encoding test. That remains true if you look at the comparative performance of FX-62 and E.E 965. The slowest Core 2 Duo of the bunch is faster than either, and the Extreme X6800 opens up, dare we say, a can of whup-ass on Presler and K8. That 4-wide execution sure helps, though.
The aforementioned can is left open in our DivX test. The pattern thus far has shown the $220 Core 2 Duo E6400 to be a match for FX-62 and E.E 965. Faster models serve to extend the performance lead.
Multi-threaded tests - professional software
Did you expect anything different? Core 2 Extreme pulverises what's gone before, and the slowest of the bunch is competitive against thousand-dollar processors, whilst only cost a fraction of the price.
Gaming
Our 2D tests have determined that the Core 2
Duo range is blisteringly fast, no matter which part of the architecture our benchmarks test. Will it be the same for gaming?
To mimimise GPU load on a stock-clocked Sapphire Radeon X1900 XTX 512MiB graphics card, we ran the benchmarks at 1024x768 with no extra image enhancement. CPU horsepower should be a telling factor, then.
Pentium E.E 965 lags a little ways behind FX-62, as you'd expect. Core 2 Duo, though, demolishes the framerates produced by both. Core 2 Extreme is 52% faster than FX-62, and Core 2 Duo E6400 is over 30% faster than the best of Intel's previous generation. Scary, huh?
The E6400's 2MiB cache doesn't seem to hinder performance much. What you should realise is that there's no mystery why Core 2 Duo's faster. Intelligent architecture design, encompassing low-latency memory access, impressive data prefetching/loading, and a 4-wide execution path all combine to produce the highest Quake 4 numbers we've seen thus far.
Splinter Cell: Chaos Theory, by comparison, appears to be GPU bound. There's not much change when looking at numbers from 'E6600 to 'X6800.
Even 3DMark05 loves Core 2 Duo.
Thoughts, HEXUS.awards and HEXUS.right2reply
Intel has learned from its overly optimistic view of Pentium 4 scaling and designed a new core architecture that simultaneously focuses on performance and energy efficiency, which, we suppose, is the Holy Grail of consumer-level computing.
It's difficult not to be wholly impressed with Intel's Core 2 Duo processors. The micro-architecture leverages a bunch of smart technologies that come together to form the most potent range of CPUs available. Putting it in some kind of context, the next-to-bottom model, E6400, costing $220, is, over the course of our benchmarks, as fast as an AMD Athlon 64 FX-62 or Intel Extreme Edition 965. That, readers, is how good Core 2 Duo is.
What's equally as impressive as sheer performance is the fact that Intel has managed to architect such power into an energy-efficient package that puts out half the TDP of the two aforementioned high-end CPUs. Even the Extreme Edition, clocked in at 2.93GHz and multiplier-unlocked, ships with a 75W TDP. We suppose it's like buying a faster, more powerful car that also gives better fuel economy than your current model. A win-win situation.
We also like the fact that Intel, unusually, hasn't jumped on to a different form-factor with the release of a new architecture. You can simply slot a Core 2 Duo in a number of LGA i975X boards or opt for a 965-Express version. Intel also assures us that it will have high-volume Core 2 Duos immediately after launch, so you won't have to wait long to get your mitts on one.
Intel, then, has moved the goalposts as far as consumer-level CPUs are concerned. Its low-end Core 2 Duo parts are more than a match for anything that has come before and its high-end models, headlined by the Core 2 Extreme X6800, have absolutely no peer.
AMD's Athlon 64 AM2 range hasn't changed an iota from yesterday to today. It's still a very sound range with solid architectural underpinnings. However, with Core 2 Duo soundly beating it in performance it's looking a lot less attractive to the consumer and system integrator alike. AMD needs to take a sledgehammer (pun intended) to current pricing if it is to remain competitive. Right now, if you're thinking of upgrading your PC and want the best solution possible for your money, you need to turn to Intel and not AMD. The empire has struck back.
It would be tempting to give the Core 2 Extreme X6800 the overall award. However, taking into account price vs. performance that award belongs to the Core 2 Duo E6400. It's a £150 CPU (once we factor rip-off Britain in the equation) that gives an Intel E.E 965 and AMD Athlon 64 FX-62 AM2 bloody noses - we love it!
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