Power Consumption and Deciphering the Results


Intel Pentium D 820 2.8 GHz Dual Core Review - Processors 50

The dual core Pentium D 820 processor (well actually our whole system) pulls in an idle load of 148 watts and 233 watts at a full load in the CineBench 2003 rendering test.  This is significantly less than the Pentium 840 XE processor at 291 watts, but it is still higher than the 660 processor which is single core and pulls 207 watts at full load.  Doubling the cores and transistor count just HAS to increase power consumption; there is no way around it.  Intel’s move to 65nm will help quite a bit, but then we’ll have some architectural changes by then as well that will affect other aspects of power usage.


The performance of the Intel 820 is both a let down and an eyebrow lifter depending on your individual point of view.  If you look at the benchmarks, weighing each of them equally, then there is no doubt that the 820 failed to impress; it fell way behind in a lot of the results.

Of course, then we already knew this was going to happen: in single threaded applications a lower clocked dual core processor is always going to be out performed by a dual or single core processor with a higher frequency.  Our gaming tests, MP3 encoding tests and various other applications proved this today.

But what did we also see?  Applications like XMPEG’s DivX encoder and CineBench 2003’s rendering running in multiple threads seeing a lot of performance gain running on a slower clocked dual core processor like the Pentium D.  Our multitasking tests also showed similar gains that just wouldn’t be possible on a single core processor, with or without HyperThreading.


This is one area where the Intel Pentium D 820 processor is really going to clean house.  Current prices on our PriceGrabber engine show the Pentium D selling for $290.  The 820 is the lowest priced dual core processor being offered from Intel and is also significantly cheaper than the lowest priced Athlon 64 X2 that will be on the market soon. 

Any user that is interested and sees the advantages for dual core processing for their home machine and their own computing situation, will surely be attracted to the lower entry price of the processor itself.

Of course, there is always a drawback — getting the cheapest CPU possible may not save you any money if you have to buy a new motherboard to utilize it; which you will.  Unless you already use an Intel 955X or nForce4 SLI Intel Edition chipset motherboard, you are going to have to shell out the money for that as well.  Current 939-pin motherboard users might find the Athlon 64 X2 to be their best financial bet, but users of all other platforms will have a toss up on their hands.

Final Thoughts

If you run only single threaded applications and only one application at a time, then that should tell you exactly what processor you need: the fastest single core CPU Intel or AMD make.

But that isn’t always the case for most users.  I would guess that most of you are frequent multi-taskers that frequently have many applications open and load and performing some calculations of some kind.  If that describes you then the benefits of having two cores in a single processor socket should look pretty inviting.  In these cases the type of applications you are running, and the amount of time your are doing the multitasking, will have to be the factors you use to gauge whether you want to shell out the money for a dual core processor now.

Another interesting fact that the Pentium D brought up in our testing was how dual cores were better than HyperThreading.  I have had several readers ask me why they should bother with a dual core Pentium D processor without HyperThreading when they had a Pentium 4 already with two logical cores.  The answer is to look at the CineBench 2003 render test: the Pentium D with two physical cores at 2.8 GHz out performed the Pentium 4 660 with two logical cores at 3.6 GHz.  In both cases the application recognized the two separate threads and ran them correctly, but the difference of about 13 seconds still remains.  HyperThreading was nice in the interim for multitasking and multithreaded apps, but dual cores are on a different level.

I have to commend Intel for opening the benefits of dual core processors to a much larger range of users than AMD has announced support for thus far by offering lower cost Pentium Ds.  The 820 is the cheapest we will have, coming in around $250, and offers a great multitasking environment for less than half of the cost of the cheapest Athlon 64 X2 4200+.  Does the performance of the 820 match that of the 4200+?  Of course not but if you can’t afford a $550 processor then it doesn’t matter much does it?

Intel isn’t going to be winning any performance awards that exceed what the Pentium 4 could do with the new Intel Pentium D 820, or with any of their current array of Pentium D processors.  At least not on current single threaded benchmarks anyway.  The performance benefits of dual cores are much more difficult to materialize and even to write about, but the benefits are there.  And with Intel pushing dual core in full swing, more and more applications and environments will be utilizing them more efficiently.  And that means even better performance for the end user.

I have set up a discussion thread in our forums here for this review. 

Be sure to use our price checking engine to find the best prices on the Intel Pentium D 820, and anything else you may want to buy!

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