Introduction



A couple of years ago AMD introduced the Athlon 64 as a successor to the Athlon XP product line. The fact that this chip could handle 64 bit instructions was new, but its most noticeable feature was the performance. Although it wasn?t running at very high clock speeds, it managed to outrun the competition. More instructions per Mhz and an integrated memory controller which reduced latencies made the Athlon 64 a very popular product, boosting AMDs popularity.

Intel went from the Pentium 3 to a Netburst Technology powered CPU design which allows for very high clock speeds but fewer instructions per Mhz, The Pentium 4 was born, later on it received an update with the Prescott core which unfortunately did not bring much new to the performance table. They relied on higher and higher clock speed increases to keep performance competitive with their closest rival AMD, but when they passed 3,4GHz and beyond the return of performance/clock speed was diminishing. When Dual Core was introduced to the masses Intel played short on the ball with their Pentium D series and soon all their desktop CPUs were Dual Core parts from the lowest 805D to the high end 965D clocked at 3.73Ghz.

While Intel was tinkering away at increasing the performance of their desktop CPUs, a smaller team of Intel engineers in Israel worked on mobile processors which needed to perform good and not consume a lot of power, they went back to the Pentium 3 design and came up with the Pentium M. This CPU was already quite promising but couldn?t match the desktop part in multimedia and global application benchmarks but it did shine in instructions per clock and low power usage. The Pentium M was quite popular with the enthusiasts out there and motherboard manufacturers didn?t wait too long to release desktop boards which accepted these mobile CPUs, low power consumption and excellent performance on the desktop was possible again with an Intel CPU. At the beginning of the 2006 Intel released the Core Duo CPU for mobile usage, but desktops boards were soon available which took advantage from these high IPC wonders.

I recently compared the Pentium M to a Core Duo here and found that the Core Duo is remarkably faster than the Pentium M, even at lower clock speeds!

Whether Intel got their idea from hardware enthusiasts or not, the product released today is but good news for the world, the Core 2 Duo is, as the name implies, the follow up of the Core Duo but now for the desktop. There have been quite a bit of performance previews of this new CPU, nicknamed ?Conroe?, on the World Wide Web and its performance has caused quite a stir.

Thanks to Intel Benelux I?m able to provide you with an in-depth look at the Core 2 Duo and Core 2 Extreme processors, with a special focus on Overclocking and Power Consumption. So I peddled over to Intel on my bike in the hot sun and picked up this material:

Intel Core 2 Duo E6700 (S775, 2,67GHz, 1066MHz FSB, 4MB)

Intel Core 2 Duo X6800 Extreme (S775, 2.93GHz, 1066MHz FSB, 4MB)

Intel D975XBX, i975X Chipset ?Bad Axe? Motherboard

I also tested these CPUs:

Intel Core Duo T2600 (S478, 2.16GHz, 667MHz FSB, 2MB)

Intel Pentium 4 D 955 EE Dual Core (S775, 3.46GHz, 1066MHz, 2x2MB)

At the time of testing I had no AMD test setup available, however the Intel Pentium D 955 has been tested and compared to AMDs best by many, so in this review it will serve well as a comparison.

Let?s take a closer look at the test setups and specifications of these parts ->

Specifications

Below you can find a short overview of the specifications. Notice that both Core and Core 2 run at significant lower clock frequencies compared to the previous Intel Pentium desktop models.



The Core 2 processors and 955 were installed on a Intel desktop mainboard, the D975XBX.

Intel 975 X Chipset + ICH7R

Intel LGA 775 CPU support Including Core 2 (starting from revision 304)

1066 & 800 Mhz fsb bus

One PCI Express 16x bus, with optional configuration of 2 x 8 graphics support

Intel High Definition Audio With 7.1 surround sound

Dolby PC entertainment Experience

Six PCI express 1x support

DDR2-667 / -533 support

8 SATA ports

8 Gb memory support with ECC capability

Advanced memory timing capability

Intel PRO/1000 LAN

More information


Core 2 Motherboards: Intel Chipsets

The Core 2 processors do work with the 975X chipset from Intel but it wasn?t actually for it and only late revisions (version 304 and beyond) support it officially. It is possible to modify an older board to support the new Core 2, but that's a very difficult process, we'll come back to that later in this article.

Different motherboard manufacturers have announced their Core 2 compatible motherboards, either based on new revisions of the 975X or the new P965 chipset:

DailyTech writes: Intel has officially introduced the new Core 2 supporting chipset?the P965 Express. Formerly known as Broadwater, the P965 Express features Intel Fast Memory Access and support for DDR2-800. Motherboards featuring P965 Express chipsets will come equipped with high definition audio and Intel Quiet System Technology which lowers system noise and heat levels.

At Computex 2006 in June there were many Core 2 compatible motherboards on display. Among them:

Based on new Intel 975X Chipset revision :

Asus P5W DH Deluxe

Abit AW9D-MAX

DFI INFINITY 975X/G

MSI 975X Platinum H V2.0

Based on new Intel P965/G965 Chipset:

Asus P5B Deluxe

Epox EP-5P965 GLI

Epox EP-5P965+ GLI

Gigabyte GA-965P-DQ6

Gigabyte GA-965P-DS4

Gigabyte GA-965P-DS3

Abit AB9 Pro

DFI Infinity 965/G

MSI P965 NEO

MSI P965 Platinum

Albatron PXP965

Albatron PXG965

Biostar P965 Deluxe

ECS PX1

Foxconn P9657AA-8EKRS2

Intel DP965LT

There are also some other older Intel Chipset which will be used for Core 2 boards by:

AsRock ConRoeXFire-eSATA2 (945P)

AsRock 775i65G R2.00 (865G)

Biostar 945P-A7A R8.0 (945P)

DFI Infinity 946PL/G (946PL)

Epox EP-5P945 GLI (945P)

GigaByte GA-946PL-S3 (946PL)


Core 2 Motherboards: Other Chipsets

Intel is not the only chipset manufacturer; others also want a piece of the pie. Chipsets that support the Conroe are:

nVidia nForce 5 Intel Edition
- Asus P5N32-SLI SE
- DFI LP UT C19SLI32-T2R/G

ATI RS600/RD600
- DFI LP UT RD600-T2R/G
- DFI Infinity CFX1150/G

VIA VT8237A
- AsRock 775Dual-VSTA

SiS 662
- DFI 662-TMG/G

Some of the chipsets are already available right now while other will shortly be released, the nForce 5 Intel for example will be launched together with the Core 2. Early testing has revealed that some parts of the nForce 4 are being used. The real nForce 5 is estimated to be released Q1 2007. But these are only rumors and aren?t confirmed anywhere yet.


Test setup

Test Setup
CPU	Intel Core Duo T2600 Intel Pentium Processor Extreme Edition 955 Intel Core 2 Extreme X6800 Intel Core 2 Duo E6700
Mainboard	Intel Desktop mainboard D975XBX AOpen i975Xa-YDG
Memory	2 * 1024 Mb DDR2 PC7200 EPP OCZ
Other	Connect 3D X1900XTX Silverstone Zeus 750 Watt PSU Nec 2050 DVD writer Seagate 120 gig 2x Seagate 200Gb SATA

Of course the memory and clock speeds have an influence on performance. Below you can see the settings we used:



On with the show, let?s start with some synthetic benchmarks ->

Sisoft Sandra 2007




The Integer results are simply stunning; it?s the most remarkable area of improvement.



Memory bandwidth is still dominated by the Pentium D, but will it have a large affect on real world applications?

SuperPi

SuperPi is a little program that calculates π up to a set number of digits after the comma. 1M = 1 million digits, 32 M is of course 32 million digits. The program can be download here. A little background info:



So SuperPi allows us to see the raw performance scaling of the CPU in our PCs. People have been competing to hold the world record, the current standing can be found at HWBot.org.





The Core 2 certainly doesn?t lack raw CPU power, it easily beats the Pentium D and leaves the Core Duo trailing.

Photoshop benchmarks

Driverheaven made this pretty nifty PhotoShop Benchmark Script which is basically a collection of actions performed on an image and the time measured for each operation, to see it in action please go here. PhotoShop CS2 was used:



The Pentium D is able to catch up with the Core Duo but the Conroe has a healthy lead, it takes the X6800 almost 1 minute less to complete this benchmark.


WinRar



While this benchmark also relies on the hard drive writing speed, the Conroe doesn?t fail to impress, taking the lead again with a noticeable margin.

Onto the 3D benchmarks ->

Futuremark 3DMarks



3DMark2001SE is dated but still gives you a good idea of raw system performance as it relies heavily on CPU and Memory speed. To no surprise, Conroe takes the lead, the Pentium D has a small lead of the Yonah @ 2.16Ghz.



3DMark03 is known for being less CPU dependant and here you see a smaller lead for the Conroe.




The latest 3DMarks see noticeable score increase with the new CPU although the Core Duo at 2.6Ghz is nearly catching up. Those of you who are into benchmarking and like to brag with high scores, the Core 2 technology has your name written all over it.

Next up, real world games ->

Gaming performance

It?s a commonly known fact that (I hope) that almost all current games are heavily video card dependant, you don?t play games at low resolutions with a $300 video card, and if you just bought a nice an expensive SLI/Crossfire setup of $1000+ you want to turn up the eye-candy. In those cases the CPU will play a very minor role and you?ll see practically no difference in performance once you pass a certain CPU speed grade.



Maybe in the future game developers will use the extra Core and horse power available to give your overall performance a boost when using a high end CPU, even when you are running at very high graphic details.

I could either show identical FPS for each configuration running the game at the resolution and quality I play them at (1600x1200 4xAA/16xAF), or lower IQ and make the games more CPU dependant. For the sake of showing an actual difference, I chose the latter.

FRAPS and a manual runthrough of the first level in Call of Duty 2 gave these numbers, average FPS:



The in-game F.E.A.R. benchmark was used, average FPS:



Hardware OC Quake 4 bench - 800*600 - id netdemo - low quality:



The Core Duo at 2.6Ghz has a hard time keeping up with the 2.66Ghz Core 2 Duo, the extra 2Mb L2 cache really pays off.

Many hardware enthusiasts like to get the most out of these systems, let the overclocking begin ->

Overclocking - Introduction

The Intel Bad Axe desktop mainboard supports some basic overclocking options. Most important to mention is that the clock speed can be raised with 30%; in steps of 1%. The classic FSB option is nowhere to be found. Besides that there are also the following overclocking related settings in the BIOS:

Enhanced power slope; Enabled / Disabled

Host Burn-in Mode Type; Positive / Negative

Host Burn-in Mode percentage; from 0 to 30 in steps of 1

FSB Frequency override; 533/800/1067

PCI Burn-in Mode; Default / 40.00 Mhz

PCI Exoress Burn-in Mode; Default or from 1001 to 109 in steps of ~1.3 Mhz

MCH Voltage Override; Default / 1.525 V / 1.600 V / 1.650 V / 1.725 V

Front Side Bus Override Voltage; Default / 1.271V / 1.333 V / 1.395 V



That?s a limited selection and with only these there is no way to reach some insane clock speeds. Luckily a larger selection is available but it?s hidden, yet it easily be unlocked.

The OC debug mode lets you change a wider range of settings, it even becomes ?pre-unlocked? with some Core 2 processors. To manually unlock the OC debug mode you need to do the following.

Just above the IDE port you can find a three-pins header with jumper. This is used for BIOS maintenance. But notice, just above that there are three unused solder points. Contact the first two (with solder of conductive paint) and now your entire BIOS is unlocked.



I found this mod at Xtremesystems.org, where even more modifications can be found. Keep in mind that modding your mainboard will void warranty and might kill your mainboard and/or processor.

With the OC Debug mode unlocked I now have access to:

CPU VID (Vcore) from 1.275 to 1.600 Vcore in steps of 0.025 V

CPU ratio Multiplier; Automatic or manual (from 6 to 60)

Enhanced power slope; Enabled / Disabled

Host Burn-in Mode Type; Positive / Negative

Host Burn-in Mode percentage; from 0 to 30 in steps of 1

FSB Frequency override; 533/800/1067/1333

PCI Burn-in Mode; Default / 40.00 Mhz

PCI Exoress Burn-in Mode; Default or from 1001 to 109 in steps of ~1.3 Mhz

MCH Voltage Override; Default / 1.525 V / 1.600 V / 1.650 V / 1.725 V

Front Side Bus Override Voltage; Default / 1.271V / 1.333 V / 1.395 V




Notice the fact that I have an option to change the multiplier. As an extra feature the retail Core 2 Extreme has its multiplier unlocked, this might be a first for Intel Processors.

You might have noticed that there is not a single memory setting. These can be found in a different part of the BIOS. In the memory section you can change memory clock speeds, timings and memory voltage. Most significant settings are beside all the possible timings:

Memory Frequency; 333 / 400 / 533 / 667 / 800 Mhz

DDR2 Voltage; Automatic / 1.8 / 1.9 / 2.1 / 2.2




Finally there is also a small section that allows you to monitor temperatures, voltages, fan speeds,?



Overclocking - The real thing !

The X6800 and E6700 were overclocked using the same following the three steps, the E6700 trailed the X6800 overclocking performance by an average of 200Mhz. Not too bad.

1) Using an air cooled Thermalright HR-01 S775 with custom mounted Scythe 120mm fan. Vcore was left at default.
2) Vcore was raised up to a level where the HR-01 could still keep the CPU cool enough.
3) Mounting a custom made phase change cooling which kept the CPU near a chilly 4?C.

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Step 1 At 1.29v default vcore the CPU was stable up to 3.4Ghz, the temperature diode read ~55?C with a very high ambient temperature of 32?C. A ~16% increase, not bad seeing as this is the top of the range Intel Core 2 Extreme.

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Step 2 Raising the vcore to 1.36v allowed an additional 100Mhz and temperature rose to ~65?C, a lot of extra heat, without a lot of extra Mhz, total OC at ~19%. An extra vcore bump to 1.48v was needed to make it to 3.6Ghz but the temperatures were too high, surpassing 75?C and the system wasn?t very stable.

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Step 3 The phase change brought low CPU temperatures and 3.6Ghz with only 1.36v vcore was stable. It took 1.55v vcore to reach 4Ghz which makes the total overclock ~36%.

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The Core 2 is an excellent overclocker if you can keep it cool enough, but even with modest air cooling (the HR-01 with Scythe fan is very silent) the OC margin is remarkable for such early samples. I only tested the higher rated models here, the slower E6600 and below might prove to have a higher overclock-ability.

Let?s take a look at the power usage and the influence of the extra CPU power on the performance ->

Power usage

Using a power consumption meter installed between the power cable and the wall outlet I was capable of measuring the full system power consumption. Stressing only one core gave a load of 50%, so in a second stage of testing I stressed the second core as well, making the cpu 100% stressed:



I monitored the power usage of the overclocked Core 2 Extreme X6800. This can be interesting as you can verify at what point the power consumption increases past the point where you can keep the CPU cool enough.



The ideal setting for this particular X6800 sample seems to be 3.4Ghz, giving you the best performance per Watt.


(chart based on average performance increases in benchmarks seen below)


Performance scaling

While the X6800 is likely to out perform any other CPU current on the market, Intel will not rest on their laurels, with higher rated CPUs planned for later this year I though it?s interesting to take a look at how these CPUs will scale performance wise, going from 3ghz all the way to 4.5ghz. So recording data in 100Mhz steps between 3-4Ghz I added a trend line to estimate future performance. While the trend line does give you an idea, keep in mind that it's not 100% correct, small deviations from actual performance are possible (in most cases the trend line shows the score too high).






The future looks bright! What we have here is a CPU with excellent performance, good overclocking potential and acceptable power consumption, but how much does it cost? Time to turn the page ->

Pricing

Is the Core 2 Duo aka Conroe better than sliced bread? A resounding "yes" is the answer. Performance is phenomenal and this without turning your case into a small oven, Intel delivered a cool and fast CPU here today. The only thing which might still spoil the party is the price, if the bread is delicious but too expensive, nobody will eat it (or something), pricing information has been revealed already and below we compare them to the other contenders in todays's bout

Using the Dutch Pricewatch I've looked up the actual prices for the chips, including some other models from the series. As you can see we've had the opportunity to play with very expensive hardware. But there are also cheaper versions available.

Intel Pentium D CPU

Intel Pentium 4 D 940 Dual Core (S775, 3.2 GHz, 800MHz, 2x2MB, Boxed) - ? 213,95

Intel Pentium 4 D 950 Dual Core (S775, 3.4 GHz, 800MHz, 2x2MB,Boxed) - ? 299,90

Intel Pentium 4 D 955 EE Dual Core (S775, 3.46GHz, 1066MHz, 2x2MB, Boxed) - ? 937,10

Intel Pentium 4 D 960 Dual Core (S775, 3.6 GHz, 800MHz, 2x2MB,Boxed) - ? 496

Intel Pentium 4 D 965 Dual Core (S775, 3.73 GHz, 800MHz, 2x2MB,Boxed) - ? 939,42


Intel Core Duo Mobile CPU

Intel Core Duo T2300 (S478, 1.66GHz, 667MHz FSB, 2MB, Boxed) - ? 202,93

Intel Core Duo T2400 (S478, 1.83GHz, 667MHz FSB, 2MB, Boxed) - ? 226,68

Intel Core Duo T2500 (S478, 2GHz, 667MHz FSB, 2MB, Boxed) - ? 276,63

Intel Core Duo T2600 (S478, 2.16GHz, 667MHz FSB, 2MB, Boxed) - ? 396,67

Intel Core Duo T2700 (S479, 2.33Ghz, 667Mhz, Boxed) ? 601,41


Intel Core 2 Duo CPU

Intel Core 2 Duo E6300 (S775, 1,86GHz, 1066MHz FSB, 2MB Boxed) - ? 182,99

Intel Core 2 Duo E6400 (S775, 2,13GHz, 1066MHz FSB, 2MB Boxed) - ? 219,80

Intel Core 2 Duo E6600 (S775, 2,4GHz, 1066MHz FSB, 4MB Boxed) - ? 307,02

Intel Core 2 Duo E6700 (S775, 2,67GHz, 1066MHz FSB, 4MB Boxed) - ? 508,42

Intel Core 2 Duo X6800 Extreme (S775, 2.93GHz, 1066MHz FSB, 4MB, Boxed) - ? 939,42

Mainboards I've used today

AOpen I975Xa-YDG, i975X (ATX, PCI-e, Sound, LAN, SATA II, RAID, 1394) - ? 243,28 for Core Duo

Intel D975XBX, i975X (ATX, PCI-e, Sound, LAN, SATA II) - ? 228 for Core 2 Duo and Pentium D

At the time of doing this review I unfortunately had no up to date AMD test setup to do comparison tests, however AMD should not be dismissed so prices for their current high(er) end line-up are included:

AMD X2 and FX

AMD Athlon 64 X2 3800+ (AM2, 2,0GHz, 2x512KB, 89W, Boxed) - ? 273,97

AMD Athlon 64 X2 4000+ (AM2, 2,0 GHz, 2x1MB, Boxed) - ? 301,57

AMD Athlon 64 X2 4200+ (AM2, 2,2GHz, 2x512KB, Boxed) - ? 338,42

AMD Athlon 64 X2 4400+ (AM2, 2,2GHz, 2x1MB, Boxed) - ? 421,33

AMD Athlon 64 X2 4600+ (AM2, 2.4GHz, 2x512KB, Boxed) - ? 518,52

AMD Athlon 64 X2 4800+ (AM2, 2,4GHz, 2x1MB, Boxed) - ? 583,02

AMD Athlon 64 X2 5000+ (AM2, 2.6GHz, 2x512KB, Boxed) - ? 569,93

AMD Athlon 64 FX-62 (AM2, 2.8GHz, 2x1MB, Boxed) - ? 968,94

Do note that AMD will announce price drops shortly after the Core 2 launch. The two AMD CPUs outlined in bold above are faster than the Pentium D 955 in many benchmarks as can be seen here and here. Yet the current AMD FX-62 is no match for the newer Core 2.

Conclusion

In my tests today I focused more on overclocking and power consumption, using one of the first samples available in Benelux there is already quite a margin, with silent air cooling and default voltage I managed to get an ~500Mhz overclock from both X6800 and E6700 CPUs. Combine this with acceptable power consumption and the Core 2 is hard not to recommend.

It will be interesting to see how the lower rated E6300 and E6400 stack up since they have only half the L2 cache available, a performance preview can be seen here at Matbe, comparing 2Mb vs 4Mb L2 at same clock speeds.

To sum up our thoughts, short and sweet:

Intel Core 2 comes


Recommended!

Special thanks to Kristof from Intel Benelux for providing us the hardware needed for testing.

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