A couple months ago, Intel unleashed their Pentium Extreme Edition
840 as the first in a series of dual core processors. On the surface,
the Dual Core Pentium looks like their current generation LGA775
processors, but underneath the heatspreader lies two CPU cores
(codenamed Smithfield) that are connected to each other by an
800MHz Front Side Bus. For those of you unfamiliar with Smithfield,
here's a quick recap:
Features for the Pentium 4 D and Extreme Edition
· Intel Extended Memory 64 Technology: introduced
with the 6xx series, the new processors feature Intel's Extended
Memory 64 Technology (EM64T), which is not much unlike AMD's solution.
There are two potential benefits to EM64T, provided you have the
OS and software in place; a faster computer and more addressable
memory.
Computing instructions are done in binary format (zero and one),
and for 32-bit environments, each bit is capable of one binary
instruction each clock cycle. Therefore, for previous Intel desktop
processors, for each clock cycle, they were capable of 32 binary
instructions. A 64-bit processor doubles that, so provided the
environment is optimized for 64-bit computing, PCs should be much
faster.
One of the greatest limitations of 32-bit processors is that
they are only capable of addressing up to 4 GB of memory. In theory,
a 64-bit CPU can process up to 16 exabytes of ram.
· Execute Disable Bit: The Smithfield will
be the third group of Intel desktop processors to support Execute
Disable Bit (XD Bit). XD Bit isn't really new for Intel, as it
was implemented for the Itanium processor in 2001 (for servers),
the Intel Pentium 4 570J last year, followed by the 6xx series
earlier this year.
How XD Bit works is certain memory pages are protected from buffer-overflow
attacks. For most Intel desktop CPUs, the x86 architecture have
no means of protection to malicious code writing themselves to
these memory pages and executing. By enabling this in the BIOS
and OS now, you can effectively shut the door on the code from
taking over these memory pages.
· More Cache: Both series of processors
have 2MB of L2 cache. Unlike the 6xx series which piles all that
cache on one core, the Smithfield has 1MB of L2 cache on each
core for a total of 2MB.
· Hyper-Threading Technology (Extreme Edition
only) : While not new to the platform, this feature allows
multithreaded software applications to execute threads in parallel.
Here lies the only difference between the Pentium 4 D and Extreme
Edition, as the "D" series will have HT turned off.
The last feature that Intel introduced was Enhanced SpeedStep
(EIST). How EIST works is it saves power by intelligently throttling
clock frequencies. The end result is lower power consumption,
and less heat. Note that the Extreme Edition 840 does not have
EIST.
Here is a table that sums up how the CPUs fare against one another:
|
Processor
|
Frequency
|
Bus
|
L2
|
XD
Bit
|
EM64T
|
EIST
|
Chipset
|
HT
|
| Pentium
EE 840 |
3.2GHz
|
800
|
2x1MB
|
Yes
|
Yes
|
No
|
955X
|
Yes
|
| Pentium
4 D 840 |
3.2GHz
|
800
|
2x1MB
|
Yes
|
Yes
|
Yes
|
945/955
|
No
|
| Pentium
4 D 830 |
3.0GHz
|
800
|
2x1MB
|
Yes
|
Yes
|
Yes
|
945/955
|
No
|
| Pentium
4 D 820 |
2.8GHz
|
800
|
2x1MB
|
Yes
|
Yes
|
Yes
|
945/955
|
No
|
All the processors run at 800FSB, and are built on the 90nm process.
As you can see, all the CPUs are more or less the same other than
the Extreme Edition not supporting EIST and supporting HT. Another
thing to keep in mind is the Extreme Edition requires an Intel
955X chipset, at least officially. Chipsets from VIA, ATI and
NVIDIA should support the entire dual core product line, though
that is up to the board makers to decide.
The
Intel Pentium Extreme Edition
840
As
introduced with the 5xx series, the Extreme Edition 840 is based
on the Land Grid Array 775 (LGA775, AKA Socket-T), and has no
pins as those are found on the motherboard now. Along with the
processor, we received Intel's stock heatsink. It is a similar
heatsink to those provided with their 5xx/6xx series of CPUs and
features aluminum fins surrounding a copper core. The fan itself
is rated for a maximum of 5000rpm, which can get quite noisy,
but when the CPU is idle or under light load, it slows down to
very acceptable noise levels.
As
with the previous Pentium 4 Extreme Editions,
motherboard support is somewhat restricted. For Intel chipsets,
you're limited to just the 955X, and while chipset offerings from
VIA, NVIDIA and ATI do support dual core processors, we do not
have any retail boards presently to test this with. Best to check
with your favorite board vendor since this is an option that they
need to configure.
Test Setup
ASUS P5WD2 Premium (955X): Intel
P4 Extreme Edition 840, 2 x 512MB Corsair TWINX PC5400 Pro, ATI
X850XT-PE, 160GB Seagate SATA 7200.7, Windows XP SP1, ATI Catalyst
5.7.
ASUS P5WD2 Premium (955X): Intel
P4 XE 3.73GHz, 2 x 512MB Corsair TWINX PC5400 Pro, ATI X850XT-PE,
160GB Seagate SATA 7200.7, Windows XP SP1, ATI Catalyst 5.7.
Going up against the Extreme
Edition 840 will be the Pentium 4 3.73GHz
Extreme Edition. Outside of the CPUs, all the setups share
similar peripheral components. Onboard audio was enabled in the
BIOS for all the boards, but not used during game testing.
Test Software is as follows:
SiSoft Sandra 2005 - Our standard synthetic benchmark
suite. While it doesn't provide real-world information, it does
give us a base for the rest of the tests.
SYSMark 2004 Office and Content Creation - A scripted
benchmark using real-world applications. Like the SiSoft tests,
higher numbers are better.
PiFast - A
good indicator of CPU/Motherboard performance is PiFast
version 4.2, by Xavier Gourdon. We used a computation of 10000000
digits of Pi, Chudnovsky method, 1024 K FFT, and no disk memory.
Note that lower scores are better, and times are in seconds.
TMPGEnc
2.521 - We used an Animatrix file, titled The
Second Renaissance Part 1, and a WAV created from VirtualDub.
The movie was then converted it into a DVD compliant MPEG-2 file
with a bitrate of 5000. Times are in minutes:seconds, and lower
is better.
CDex Audio Conversion Wav to MP3 - CDex
was used to convert a 414MB Wav file to a 320kbs MP3. Times
are in minutes:seconds, and lower is better.
Doom 3, Far Cry, Unreal Tournament 2004 @ 640x480, LQ Settings
- While higher resolutions tax the video card, lower resolutions
rely on CPU and subsystem speed. These results are real-world,
and higher scores are better. Bench'emAll
was used to collect numbers from Far Cry and UT2004.
Windows Media Encoder 9 - The first of our multithreaded
tests, we will be converting a 380MB AVI clip to WMV. This is
an Intel recommended test, but it should be effective for testing
any dual core CPU.
ABBY - We used a retail OCR software suite to process
an Adobe Acrobat document. The final time is the total length
the application needed for the OCR process. ABBY is one of the
first consumer level applications to take advantage of dual core
processors.
We will also be demonstrating real-world performance in not so
real scenarios. While it's rare for people to do a DVD rip while
playing a video game, we did want to test the 840's prowness at
handling multiple multitasking loads. We selected DVD Shrink since
it's a very popular app, copied the contents of Matrix: Revolutions
to our hard drive (to rule out optical drive influences) and shrunk
the package to 67%. We were not timing the shrink, but used this
test to load the CPU for the multitasking tests.
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