Mobile Overclocking

Anyone familiar with overclocking desktop systems probably has certain preconceived notions about how overclocking will affect a laptop. We certainly had our fair share, but the requirements of the platform as well as Dell's take on mobile overclocking make things a bit more complex, at least in terms of the performance offered. With a desktop system, there are all sorts of BIOS options that can be tweaked in order to maximize your system overclock and improve performance. Overclocking of the M1710 is also accomplished via the BIOS, and there's only a single setting to change. This is simplicity in overclocking at its finest, but the results may not be what you expect.

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There's no need to worry about voltages, memory speeds or timings, or anything else. Basically, you just set the appropriate CPU speed within the BIOS, reboot, and you're off and running. There are six overclock settings available, with clock speeds ranging from the default 2.33 GHz up to the maximum 3.16 GHz in 166 MHz increments. We will refer to these overclock settings as Bin-0 through Bin-5. Amazingly, system stability was absolutely never a problem in well over a month of strenuous testing. Regardless of what setting we chose, we didn't have a single crash or lockup of the XPS M1710. Considering we were setting the CPU to run at as high as 37% over factory default (the maximum 19X CPU multiplier the BIOS allows) and were dealing with a CPU running in the cramped confines of a notebook, we were more than just a little pleased with how easy it was to improve system performance via overclocking. However, as we mentioned, the end results are a little bit more complex than simply choosing a setting and forgetting about anything else.

Unlike on desktop systems, where you can basically force the CPU to always run at a specific speed, laptops usually enable power saving features that allow the processor to run at slower speeds. Core 2 Duo mobile processors can run at 1.0 GHz in their low-power state, and this doesn't change with overclocking on the M1710. When the system is idle, regardless of what Core 2 Duo processor you're using, the M1710 will run at 1.0 GHz. That's not really a problem, since if the system is idle it doesn't need to run any faster. Once you start doing some work that requires more processing power, Intel's SpeedStep will increase processor speed to deal with the demands of whatever applications are running. If you disable SpeedStep within the BIOS on the XPS M1710, the CPU will always run at 1.0 GHz.

Once a load is placed on the processor and the CPU speed begins running at the maximum clock speed you've selected within the BIOS, temperature comes into play. If the processor becomes too hot, clock speeds can be temporarily reduced to a lower value, and once temperatures have dropped back to acceptable levels the clock speed will increase again. Being a dual core processor, we found that the CPU throttling only occurred when both cores had a significant load, and even then throttling only occurred at the two highest overclock settings during our testing. However, the test environment will certainly play a role in how hot the system gets, and if you're actually daring enough to run CPU intensive applications with the notebook sitting in your lap with your legs potentially restricting airflow into the bottom vents, throttling may occur more frequently.

It's difficult to say exactly how often the CPU will throttle back, but we did some basic testing of performance using the Windows SMP version of Folding@Home. This allowed us to look at performance with the CPU under load for long periods of time, and what we found is that performance increases tapered off beyond the Bin-3 setting. At the stock Bin-0 setting, Folding Project 2610 averaged around 16:30 (minutes:seconds) per segment while at Bin-3 folding times dropped to around 14:25. Bin-4 and Bin-5 were both about the same as Bin-3, but there was greater variance in segment times. It could be as low as 13:50 and as high as 14:30 per segment with the average being roughly 14:15 and the theoretically slower Bin-4 usually averaged fractionally (i.e. a few seconds faster per segment) better times than Bin-5. We loaded up CPU-Z while Folding@Home was running and found that Bin-0 through Bin-3 never experienced any CPU throttling; at Bin-4, CPU-Z would show a clock speed of 3.0 GHz for about 15 seconds followed by a clock speed of 2.67 GHz for seven or eight seconds; and at Bin-5 the CPU throttling was much more rapid, usually running at 3.16 GHz for a few seconds followed by 2.67 GHz for a few seconds, and sometimes even 2.33 GHz for brief periods of time.

After discovering this behavior, we determined we needed to investigate the performance situation further to establish the optimal overclock setting, if such a thing existed. We ended up running all of our benchmarks at every overclock setting, with somewhat interesting results. In some applications, the higher overclock settings were always faster; in others, the CPU wasn't the bottleneck and all of the scores were nearly equal; in still others, performance was actually lower at the top two overclock settings. Performance variations were also quite a bit larger, particularly at the maximum Bin-5 setting, most likely due to variations in how much CPU throttling occurred during the benchmark run.

System Features Overclocking Performance - General Applications
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  • Tommyguns - Friday, May 11, 2007 - link

    $4000 for a laptop to play games on?!
    Not trying to bash the artical, but whats the point of testing products if the actual market niche for such products is sooooo freaking small!?

    $2000, on a laptop is a lot of money. adding in the fact it needs to play games, do that many people really spend past 3k on one? let alone 4k+?

    If 10-20total fps in DX9 games is worth $2000, then someone let me know...

    Dell inspiron E1705 with a C2D T7200, 7900GS vid card, gig of ram, 9cell + 6cell battery, DVDRW, vista home pre., 17 inch UltraSharp Wide Screen UXGA Display, wireless N card,and a few other odds and ends can be had for $1875. Toss in one of the coupons available online, like the $500 off and its just shy of $1400 for a decently effective gaming laptop. is it the best buy? idont know, but the best well rounded one. also, the XPS 17inch laptop on dells site, with the same parts, retails for around $ yes, no coupon...but still.... I like dell, yet dislike them equaly as much.

    Thus, review a 7900gs dell offering so us poor people can see what an additional $1200+, really can do...Thanks... I would buy tommorow if i knew what all these machines did in terms of gpu power
  • JarredWalton - Friday, May 11, 2007 - link

    Part of the point of the article was to show that the added CPU speed did little to nothing for gaming, so if you're interested in a gaming laptop I'd recommend getting something like the XPS M1710 but sticking with a T7200 and just maxing out the GPU. You can do that for under $3000. Also remember that the configuration as tested has a $500 Blu-ray drive thrown in that many won't care about. So, cut down the CPU ($700) and the BRD ($500) and it's a lot more reasonable.
  • ziddey - Wednesday, May 9, 2007 - link

    Hi, this is definitely an interesting article, but I was a little disappointed in how it was presented and the testing done on it. I hope to not offend, but if you still have the ability to retest further, here's some ideas.

    So we're talking about throttling. If that's the case, how hot is it getting? You can track coretemps of meroms. The popular rmclock can also show any form of throttling in log form as well, and also shows it in graphical format as well. It also features ability to manipulate some finer features of it, although of course, at your own risk.

    Further, I'm assuming this is only possible on upwards unlocked cpu's. In that event, could you just use something like crystal cpuid to change the multiplier?

    Most significantly, how about this: If temperatures are still in line (and based on the track record of conroes, I see no reason they shouldn't, as long as vcore is as low as merom's are), can you set to maximum overclock in bios, and then use rmclock to force maximum multiplier while on AC
  • Deusfaux - Wednesday, May 9, 2007 - link

    either you're homeless or you have an excessive amount of money and a butler or i dont know what

    but for all the reasons that make a laptop advantageous over a desktop, you strip them all away by attempting to make it one of the gaming variety.

    ridiculous cost
    battery life
    hardly upgradeable

    I feel bad for the continual string of people who are convinced they can get all the benefits of a powerful desktop in a portable package (and not end up being inferior in every aspect)

    Get a laptop that has good portability, get a powerful desktop for gaming. dont try to do both in one.
  • araczynski - Tuesday, May 8, 2007 - link

    sounds like its a nice laptop for 1280x800 gaming. curious what the screen looks like at that resolution, in comparison to the native resolution 'sharpness'. Does it scale very well or look as crappy as you'd expect the desktop to look at that resolution?
  • suryad - Thursday, May 10, 2007 - link

    More like 1920 x 1200 gaming all except for Stalker which I dont care for much anyway. I am getting this bad boy tomorrow or next week Monday. Can't wait. Worst part is the wait to receive it in your hands...hope i can last the weekend. Also the 3dmark scores area bit low...ntoebooforums people are reporting slightly higher scores...but anywho...super speed here I come!
  • kalrith - Tuesday, May 8, 2007 - link

    The spec page on page 2 shows *q* every place that quotation marks should be.
  • Gary Key - Tuesday, May 8, 2007 - link

    Fixed, sorry about that, we are on a new engine now, bugs still seem to pop up. ;)
  • JarredWalton - Tuesday, May 8, 2007 - link

    Heh... Gary's being nice to me. I screwed up my own table by reusing parts of an old article and forgetting to properly "convert" the generated HTML file into a clean format. That's what sleep deprivation will get you.
  • redfirebird15 - Tuesday, May 8, 2007 - link

    Is it really possible to get thousands of FPS on Supreme Commander? I've never actually played it, but that looks like a typo. If that is correct, what is the difference between getting 500 FPS and 1000 FPS? I thought it was and RTS anyway.

    It must be a typo.

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