Performance of 2.5 Year Old 2 Ghz Pent. M (Tecra 9100) vs 2 Ghz Sonoma Pent. M in M4?

Discussion in 'Toshiba' started by Barry J. Doyle, Jun 29, 2005.

  1. djstabletpc

    djstabletpc Pen Pal - Newbie

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    I have a Tecra 9100 Pentium M 2 Ghz. I am happy with performance and have been holding off on additional purchases because "Centrino" plunged processor speeds back to 1.5 Ghz for two years.

    I have heard a rumor that lower speed Centrinos were faster than higher Ghz original Pentium Ms.

    Now that we have Centrino Pentium Ms (Sonoma ?) - I am confused on what I should expect for performance.

    I understand that the mother board is much more capable and faster memory - that's very nice - but is the raw processor speed the same?

    Thanks,
    D.
     
  2. Brian

    Brian Scribbler - Standard Member Senior Member

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    Well sort of. They come in 2GHz, the same clock speed, but there's a faster bus and more L2 cache, meaning fewer calls to system RAM and faster performance. I think very few people need the power of a current PM 2.0, unless you have CPU intense apps, I'd drop down to the 1.8.
     
  3. SuperRob

    SuperRob Pen Pal - Newbie

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    First, let's clarify some terminology. There is no such thing as a "Centrino" chip. Centrino is a platform that combines a Pentium M processor with Intel's wireless technology. When the two are mated, an ISV can call a system "Centrino". If they use a different wireless solution, they can't call it Centrino. The processor is a Pentium M regardless.

    That said, the Pentium M has a higher IPC (instructions per clock cycle) than the Pentium 4 desktop processor, so at the same Ghz speed, a Pentium M would be a "faster" processor. When I say faster, of course, I mean capable of processing more information per clock cycle. Incidentally, this is the same reason why AMD processors perform so well compared to equal speed Pentium 4 processors ... higher IPC. A Pentium M processor at 1.6Ghz is roughly equivalent in processing performance to a 2GHz Pentium 4.

    Now then, the early Pentium M processors were also known by the codename "Dothan". "Sonoma" is the codename for the newer Pentium M processors. Both can be called "Centrino" if using an Intel wireless chip (so you can have a Dothan Centrino, or a Sonoma Centrino).

    Sonoma is capable of higher bus speeds because it uses a more advanced chipset (any combination of a memory controller chip, north bridge chip, and south bridge chip), so an equivalent processor speed on a Sonoma might indeed feel faster than a Dothan processor. Sonoma also have the ability to use DDR2 RAM and SATA hard drives, both of which will increase performance as well. The "speed" of a laptop is a carefull balancing act of a lot of different technologies.

    In your case, however, you said you had a Pentium M 2Ghz processor (sounds like Dothan) already, and were wondering if it would be faster with the same processor in a Sonoma-based machine. The answer is "probably". Sonoma is a more advanced chipset, and there will be some small performance gains across the board, so it should be marginally faster. Is it worth upgrading to a whole new machine for? Not likely.
     
  4. djstabletpc

    djstabletpc Pen Pal - Newbie

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    I definitely tap out the 2 Ghz now. I use VMWare and Photoshop. Even with two 7200 RPM drives, photoshop takes a significant amount of time to come up. If I edit camera raw files in 16 bit mode (on 4 megapixel) and apply any type of effects - wait time is very noticable.

    D.
     
  5. Barry J. Doyle

    Barry J. Doyle Scribbler - Standard Member Senior Member

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    Going from your older Pentium M CPU-based Tecra (which has a 400MHz front side bus and a slower chipset) to the newer "Sonoma" platform (featuring a 500MHz front side bus and a speedy PCI Express chipset) will give Photoshop a significant boost in rendering times. A faster hard drive will not help much with those tasks as they are processor intensive.

    Also remember that extra RAM in your system means that Photoshop will require less space on your hard drive for temporary "scratch disk" space - which will also be a huge help.
     

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