Sixteen months ago, Intel released a confusing little thing called Centrino; it wasn't a new processor or chipset, but rather a "technology". Intel pumped billions into the marketing of this technology and even to this day, we still see the same "What is Centrino?" question. But unlike most multi-billion dollar marketing campaigns, Centrino wasn't a hip name masking uninteresting technology; instead, Centrino encompassed one of the most impressive microprocessor architectures to ever come out of Intel: Banias.

We had all heard about Banias, which was officially named the Pentium M, for almost two years, but most shrugged it off as a rebranded Pentium III. With the Pentium 4's power requirements climbing, it was all too easy to believe that Intel would just go back to a much cooler running architecture for the future of their mobile processors. Pentium M became known as a Pentium III with the Pentium 4's Front Side Bus long before it ever shipped, before the first benchmarks were ever run. But as we just finished mentioning, this processor was far from rehashed technology.

Last year, we took an in-depth look at the Pentium M and came away from the experience extremely pleased. Our sentiments were echoed by manufacturers and end users alike, with the Pentium M and Centrino notebooks that use the processor selling extremely well and truly enabling high performance, long battery life, thin and light notebooks. Offerings like IBM's Thinkpad X series grew extremely popular among business users while more stylistic options, like the Sony VAIO X series, brought a new meaning to portable, with Pentium M designs weighing less than 1.8lbs. What Pentium M brought Intel was the portability and form factor advantages of Transmeta, with the performance that Intel customers were used to.

To put it bluntly, Intel's Pentium M was an instant success and well deserving of the success at that. But in our long running history at AnandTech, we've never been quite satisfied with one successful product - we want to see improvements, perfection of the perfect, if you will. And thus, it was no surprise that we were quite eager to take a look at the follow-up to Intel's 0.13-micron Pentium M, code-named Dothan.

We first heard about Dothan before Banias ever hit the streets as Pentium M. If you'll remember from our original article on the Pentium M, Banias only missed its target completion date by a matter of days. One by-product of on-time execution was that a number of architectural tweaks that the design team wanted to get into Banias had to be left out, a sacrifice made to preserve on-time execution. As soon as the Banias design was complete, those final architectural tweaks and enhancements that didn't make it into the first Pentium M incarnation were at the top of the list for its successor. As a result, Dothan is best viewed as a more polished evolution of Banias, with higher clocks and more cache made possible by Intel's 90nm process.

But unlike Banias, Dothan wasn't the perfect student on time to its launch; instead, Dothan was released after months of delays. Intel has already publicly released the reason for Dothan's delay. There was apparently an analog design issue with Dothan; more specifically, a PLL was too jittery. Dothan was actually in the hands of OEMs back in January, but the yields were extremely low, thanks to the jittery PLL issue. The solution to the problem required another spin of the silicon, which takes a long time (even longer at 90nm) and resulted in Dothan's lengthy delay.

Being an evolutionary, rather than revolutionary part, Dothan isn't nearly as exciting to talk about as Banias was, but as you'll soon see, that doesn't take away from its worthiness of carrying the Pentium M name.

A quick look back at Banias
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  • eBauer - Friday, November 19, 2004 - link

    I'd like to see a P4 3.2-3.4 w/ dual channel DDR3200 used instead of single channel DDR2700 that was used for the P4 testbed - as a rough idea where a Dell 9100/XPS, for example, would fall in line with the Dothan. Reply
  • bhtooefr - Saturday, July 24, 2004 - link

    Something else I noticed - where's the Banias 1.7 and the Dothan 735? It would make comparing Banias to Dothan so much easier to do that...

    Also, what motherboards did you use on the desktop chips?

    #25: Take a look at http://cpu-museum.de/forum/viewtopic.php?t=1089. PowerLeap actually DID have something in the works, and was going to release in Quarter 1, but they cancelled it because of (well, at least this is what they said - I wouldn't be surprised if it was because Intel held them at gunpoint) LGA775 coming out (which can't really work with an adaptor) and the fact that the P-M wasn't running at 2.0GHz (I told them about Dothan, though).
    Reply
  • Zebo - Saturday, July 24, 2004 - link

    What are you talking about #4 and #17?

    Intels "dominace" in encoding? Those days are history my friends. If they ever were.

    Anandtech's article published just before this one was proves it. Here's a quote:

    "It was difficult to resist being a little sensationalist in this 939 roundup and titling the review, "Who needs 925X?" That would have been a fair title, however, since you can clearly see that all of the Socket 939/FX53 boards completely outperform Intel's top 560 on the top 925X motherboard. Even Media Encoding, the last bastion of Intel dominance, has fallen in benchmarks with our new AutoGK benchmark. "

    As a matter of a fact it's always been a mismoner if you look at other suites/Codecs such as:

    Codecs: xVID

    Consumer programs: Ulead VideoStudio 4,5,6 and 7. Roxio videowave 4,5,6 and 7. Pinnacle studio 7.


    MPEG2 Encoders: Canopus procoder, Ligos, bbMPEG.
    DVD transcoding: DVD2AVI, VirtualDubMod

    Freeware: VirtualDub.

    Streaming: Quicktime.

    Shot out to alex;)
    Reply
  • T8000 - Thursday, July 22, 2004 - link

    Since the Pentium M shares its bus protocol with the Pentium 4, I think companies like Powerleap should be more then able to provide an adaptor for desktop use.

    This would likely result in an "Intel unknown" detection, along with a lack of power save options, but previous experience with the "Tualatin" P3(1400) learned that this could work and even offer full performance compared to a full recognition.

    Also, I think the limited memory bandwith did not hold Athlon 64 back, because I still remember seeing Athlon FX (dual channel) and 64 (sinle channel) perform almost equal for the same clockspeed. However, the Pentium 4 would benefit from more bandwith, as happened before on every FSB bump it got. So I think adding faster memory would only make a noticeable difference for the Pentium 4.
    Reply
  • SKiller - Thursday, July 22, 2004 - link

    I didn't say it would make up *all* the performance, but enough to make it competetive. For example: the P4 is essentially faster than A64 in those tasks but the A64 is still sufficiently close to be a viable altermative. Dothan doesn't have to beat the P4 in media encoding or content creation, just come close enough to be a good desktop CPU. It should be possible by increasing the FSB. Reply
  • Xentropy - Thursday, July 22, 2004 - link

    #3 - "As you'd expect from 90nm, the leakage power has shot right up, meaning that in its low power states, the CPU is draining a great deal more power than Banias."

    Oh? Link to more info on this, please.
    Reply
  • TrogdorJW - Wednesday, July 21, 2004 - link

    One comment I forgot to mention: even with the talk of thermal design targets and clock speed limitations, I imagine that a Dothan CPU in a desktop motherboard with a large copper heatsink would have quite a lot of overclocking headroom. I know there was a French site that claimed to have overclocked a Dothan to 2.4 GHz, and the performance was quite impressive (if true). I would really like to see overclocking results for Dothan (and Banias) on a desktop system. With processors designed to generate 1/4 the amount of heat of a P4 3.2+, it could be interesting. Here's hoping some motherboard manufacturers will accommodate us! :) Reply
  • TrogdorJW - Wednesday, July 21, 2004 - link

    Overall, I thought this was a great article. Those complaining about various configuration issues need to stop whining. Never once did AT actually give out any numbers for battery life or low-power performance, or claim that the Dothan was beating a desktop Athlon 64/P4. All we're looking at is what the various can do in typical *laptop* configurations. Getting a P4 and A64 laptop would make them into real laptops, but then we would have the laptop manufacturer's configuration, and likely it wouldn't be the same as what they had for the Dothan system. What we've got is three platforms running the same RAM, Hard Drive, and graphics card. Yes, it's limiting what some of the CPUs could do, but it's about as fair as you can get.

    Of course, if history is any indication, I'm fairly confident that Dothan is going to dominate other mobile architectures in battery life - when using the same screen, hard drive, and battery. Too bad it's so difficult to actually meet those criteria. Screens differ quite a bit, and many P4 and A64 laptops are shipping with 90+ kWhrs batteries, while Banias and Dothan laptops often get by with 60 to 70 kWhrs. Anyway, the Banias was generally the best laptop CPU before (i.e. most efficient while still providing good performance), so why shouldn't the Dothan be similar if not better? The results are hardly surprising.

    I really hope that we one day see some desktop boards designed for Dothan, though. I imagine that getting the FSB up to 200 MHz quad-pumped should be possible, although even 133 or 166 would be helpful. Combine a Dothan CPU with all the other desktop accoutrements, and it would likely be a formidable gaming platform. Of course, it would really only be about the same as Athlon 64, and Intel is currently milking the Dothan/Banias line for all they can. $600+ for a processor that probably costs Intel less money to create than their P4 chips.

    Again, great article, Anand. (And for the interested, Jon "Hannibal" Stokes over at Ars Technica put together as much information as I've seen anywhere about how the internals of the Banias/Dothan function. Not much detail in comparison to other CPU comparision articles he's written, but there is some additional information about what ops can benefit from the fusion technique, IIRC.)
    Reply
  • rocketbuddha - Wednesday, July 21, 2004 - link

    Acer(for sure) & Emachines(AFAIK) use a 4200 RPM HDD not a 5400 RPM HDD.

    The problem is that the available Athlon laptops are castrated in some level

    a) Poor Graphics card(This changed with A64).
    b) Lower speed HDDs.(Of course Aleinware, FNW fix with high end components pricing goes to the roof.)
    c) Only 4 from a list of 32 varying modes by PowerNow!

    With these either of these three there no way would a mobile A64 laptop would be in its best form for comparision.
    Reply
  • SnakeJG - Wednesday, July 21, 2004 - link

    I would also like to see this review updated with an Athlon 64 with 1 meg L2 cache. It seems a shame to compare an expensive 2 meg L2 cache Dothan with the cheaper 512KB L2 cache Athlon 64's. In addition, by keeping Athlon 64's to the slower/single channel RAM, you are making the L2 cache more important than normal, and hindering the Athlon 64. Reply

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