Power

Closely related to battery life is the topic of system power draw. After all, a system that requires more power to run will typically provide less battery life. We used a Kill-A-Watt device with the batteries removed in order to record system power requirements. We also tested with minimum and maximum display brightness to show how that particular setting affects power draw, except on the maximum load where we used the brightest display setting. Please note that these are most definitely not equivalent configurations: the ASUS has a larger LCD, faster GPU, and a larger 7200 RPM hard drive, all of which should increase power use. Here are the results.

System Power Draw (Watts)
Boo! Scared you! Idle 100% CPU Maximum
ASUS A8JS 26-32 47-52 71
MSI TL-50 2x512MB 17-21 43-48 58
MSI TL-50 2x1024MB 17-22 45-50 61
MSI TL-60 2x1024MB 19-24 50-56 66

The MSI configuration with the slower TL-50 processor clearly consumes the least power. However, what's interesting is when we get to the "equivalent" configurations. The ASUS laptop still has a faster graphics processor, but what's particularly interesting is that it's the idle power consumption that really seems to affect battery life of the ASUS laptop the most. When the CPU is under full load, the ASUS system actually uses less power than the TL-60 MSI configuration. Adding graphics work to the CPU load results in the ASUS using slightly more power, but considering the higher performance it offers the extra 5W is a reasonable sacrifice. The problem comes in idle power draw, where the ASUS laptop consumes 7-8W more power than the MSI TL-60.

This leads us to an interesting conclusion in regards to battery life and power requirements. First, at maximum load the GeForce Go 7700 really doesn't apprear too bad, all told. At idle, the GPU seems to hurt the ASUS in power draw, although it could also be that the Core 2 Duo chip isn't dropping to as low a power state relative to the Turion X2. The likely explanation has to do with the old topic of AMD's integrated memory controller, along with CPU clock speeds. Both the Core 2 Duo and Turion X2 regulate processor speed by changing the CPU multiplier, but the final result is different.

First, the Turion X2 has a lower minimum multiplier of 4X with a HyperTransport bus speed of 200 MHz, resulting in a CPU speed of 800 MHz. That might seem like a relatively slow processor these days, but if your system is just sitting idle you don't need a lot of unused clock cycles. In contrast, Core 2 Duo has a minimum multiplier of 6X with a bus speed of 166 MHz, resulting in a minimum clock speed of 1000 MHz. Right there, Core 2 Duo is running 25% faster (proportionately) in its lowest sleep state.

Going back to the integrated memory controller, AMD also reduces your memory performance along with the slower CPU speed in order to further conserve power. AMD bases your memory speed off of the CPU speed, and in the case of the TL-60 using DDR2-533, at maximum CPU speed the memory is running at CPU/8 or DDR2-500. When the CPU goes into sleep state, the memory divider is also modified. In the sleep state, the memory runs at CPU/5 or DDR2-320. Memory and CPU voltages are also reduced, so the net result is that AMD is able to use less power when the system is in an idle state.

Does that make the Core 2 Duo worse at power saving than Turion X2? Without equivalent setups (i.e. both using IGP or both using discrete GPUs), we can't say for certain. We can say that an ASUS W5F with a T2300 chip (1.67GHz 2MB cache) that we had at one point bottomed out at 19W in idle mode, so Core Duo and Turion X2 appear close in low power states, with Turion X2 perhaps holding a slight 1-2W advantage. Our testing of Core Duo vs. Core 2 Duo showed the CPUs to be nearly equal in power draw, so it appears AMD is equal or slightly better than Intel at minimum power draw. At maximum power draw by the CPU, Turion X2 is definitely using more power than Core 2 Duo, as even with higher performance/power components the ASUS A8JS still uses less power than the MSI TL-60 at 100% CPU load.

Temperatures

So with the information on power requirements and performance, some of you are probably wondering how hot these systems get. Are they truly "laptops", or would they be more at home on the top of a desk or table instead? We checked temperatures over the surfaces of both systems in their maximum configurations at full load. The systems were placed on a flat, hard table surface with an ambient temperature of 23°C.

System Temperatures (Celcius)
Trick or treat? Palm Rest Keyboard Bottom Exhaust
ASUS A8JS 25-32 31-36 25-39 46
MSI TL-60 2x1024MB 27-31 31-38 29-41 48

There are several factors at play here. First, from the power requirements we know that the ASUS laptop is only consuming slightly more power. This is counteracted by the fact that it has a larger surface area, resulting in overall lower temperatures. We didn't tear apart the ASUS system in this article, but the cooling configuration is also slightly different, and there are more vents on the bottom of the ASUS A8JS. Both systems remained quiet during use even under maximum load (right around 30 dB, which is the limit of our SPL meter), but the ASUS was slightly (< 2 dB) louder during gaming sessions where the GPU and CPU are both active. More fan noise means more cooling power, which can also account for the lower temperatures on the ASUS system.

The surfaces of both laptops range from just slightly higher than room temperature up to moderately warm. Neither gets extremely hot, and most people would be okay with placing these systems on your legs, even with direct skin contact (don't mind the sweat). The only real problem we have with using either system on your lap is that this would tend to block the system fan intake, which could lead to higher temperatures and possibly even stability problems. We did use both systems in less ideal situations where the fan intake was at least partially obstructed, however, and didn't encounter and issues.

Battery Life A Quick Look at Gaming/Graphics Performance
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  • ShapeGSX - Monday, October 16, 2006 - link

    The Core 2 Duo mobile processors DO support 64 bit instructions!

    Core Duo does not.
    Reply
  • randomas - Tuesday, October 17, 2006 - link

    Doh! I guess I should have checked then, but all the more reason to see them both pull their weight with a real OS! Reply
  • Wesleyrpg - Monday, October 16, 2006 - link

    hey all,

    im eager to see a review of the a8js, thats the laptop that i got my eye on at the moment, if asus play their cards right, the a8js could become one VERY popular laptop.

    Any idea on availability though on the A8JS?
    Reply
  • piesquared - Monday, October 16, 2006 - link

    Good review, but which system was being reviewed, the Asus C2D or the MSI X2? Reply
  • duploxxx - Monday, October 16, 2006 - link

    Nice comment, whenever it fits there results, they will publish it.. (does remember me of the time you would test 2P wood-opty in windows, but probably the result was not as expected of your sponsor). Also the memory issues do question your results......

    the core2duo is for sure the better performing one. Few months ago the X2 versus coreduo was a tight battle, but we all saw the core2duo outperforming the coreduo with glance, so the same thing happens with turion. Intel made his design for laptop and changed it up to desktop and server, AMD did it the other way around.... so for a 3year old design I think it was rather good against all those updating Mobile en core technologies from Intel.

    Now from an other perspective. Most of the laptops are supplied with Intel internal graphics. How Will this perform against the ATi Graphics? that would be an interesting review.......
    Reply
  • JarredWalton - Monday, October 16, 2006 - link

    ATI Xpress 1100 is about twice as fast as GMA950, plus it has full DX9 support (though not SM3.0). Problem is, it's pathetically slow still. I mean, what can you want that the Xpress 1100 can provide but the GMA950 can't? 20 FPS at minimum quality in HL2? If you want 3D performance, I'd say the 7700 in the A8JS is a good starting point. X1400 and GeForce 7400 are both substantially faster than Xpress 1100, buth still pretty sluggish for actual 3D work. X1400 is still okay for video playback and older games (as is 7400), but you can get 7600/7700 for about the same cost I think. Reply
  • JarredWalton - Monday, October 16, 2006 - link

    MSI today, ASUS later this week. It's probably already clear which one we preferred, but there's more to say about the ASUS and putting out a 14000 word article seemed like overload. Reply
  • piesquared - Monday, October 16, 2006 - link

    Yes, i know, and sorry for the sarcastic question. I guess i'm just wondering why so much content on the Asus solution, when as you say there will be a seperate review later this week. My overall picture of that article was that AMD's solution was a steaming pile of mess not really suitable for anyone. At least that's the impression i(and probably most visitors that read or will read it, so i guess it was successful that way) got, regardless of any conlusion throwing it a bone here and there. What i can't understand is why MSI would even offer up such an abomination for review!! ;)

    BTW, i did think it was a very good article, aside from the above mentioned slant that seem to ooze from it..

    Reply
  • JarredWalton - Monday, October 16, 2006 - link

    It's basically a case of getting an okay system, but we would say there are better options out there. If the MSI is cheaper, faster, has more battery life, or some other benefit than other competing laptops, great. It's basically at best equal to other ultraportable options.

    The ASUS W5F with Core Duo is about as fast (with "slower" integrated graphics, though it doesn't matter much), but it costs more, so there you could say the S271 is "better". Unfortunately, there aren't many faster Turion X2 notebooks around, other than the MSI MS-171772 mentioned in the conclusion.

    If all you're after is ultraportables, the MS-1058/S271 is about all I see for Turion X2. It does tend to be about $100-$200 cheaper than any Core 2 equipped ultraportables, or about the same cost as Core Duo equipped ultraportables. In that market, it has a place. I'm not a huge fan of ultraportables, but some people are. I'd personally rather carry an extra 2 pounds and get a 14" (or larger) display.
    Reply
  • aidanjm - Monday, October 16, 2006 - link

    you rip apart a closed system not designed to be opened up by the consumer, fiddle around inside, then complain when things don't work? even the complaints on memeory compatability seem lame. Reply

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