Overclocked Performance: Win Some, Lose Some

Like the M11x and ASUS' UL series of CULV laptops, the M11x R2 allows you to try overclocking the CPU via the BIOS. Whereas we could simply set the bus speed to 166MHz (from the default 133) with the other laptops we've tested, this is our first Arrandale ULV processor and it didn't quite make it to a 166 bus. At 166, the system would reboot twice and revert to 133. A 164MHz bus on the other hand would boot Windows most of the time, but various games and applications would crash. Eventually we settled on 160MHz and achieved full stability.

Note that the stock multiplier for the i7-640UM is 9x, but with Turbo Boost it can go as high as 17x. You can disable Turbo Boost in the BIOS, but even at a 166 bus speed you would then be stuck with a constant CPU clock of only 1500MHz. At 160MHz we still saw multipliers as high as 17x, but not as often as when we were on the stock 133MHz bus. What's more, in heavily threaded benchmarks the multipliers were much lower on average, with the system often running at the "minimum" 9x. (SpeedStep can still drop down to a 5x multiplier, but under load we always stayed above 9x.)

So, what does overclocking get you? In certain situations we got much better performance, but overall it wasn't worth the effort in our opinion. Here's a table of our results.

M11x R2 Overclocking Gains - Applications
160MHz Base Bus
Application Stock 160 Bus Percentage
3DMark03 15421 16096 104%
3DMark05 11015 12124 110%
3DMark06 6973 6990 100%
3DMark Vantage (Entry) 14441 14484 100%
PCMark05 4597  4822 105%
PCMark Vantage 5329 5339 100%
Peacekeeper 2916 3247 111%
Cinebench 1CPU 2940 3429 117%
Cinebench xCPU 5713 5241 92%
x264 Pass 1 29.72 29.23 98%
x264 Pass 2 7.68 7.23 94%

The workloads that are primarily single-threaded in nature showed the biggest improvements. 3DMark03/05 both increased, with Peacekeeper and the single-threaded Cinebench result showing the greatest benefit. Most of the remaining tests showed no benefit, and in the case of heavily threaded tasks the bus overclock actually reduced performance. So from a general application standpoint, we can't see a reason to bother with the overclock; let Intel's Turbo Boost do its thing and be happy. But then, this is a gaming laptop and games are sometimes more single-threaded in nature. Can any games benefit from overclocking?

M11x R2 Overclocking Gains - Gaming
160MHz Base Bus
Game Title Stock 160 Bus Percentage
Batman: Arkham Asylum (Very High) 63 62 98%
Battlefield: Bad Company 2 (Medium) 31.6 32.1 102%
Crysis: Warhead (Mainstream) 32.5 36 111%
DiRT 2 (Medium) 34.8 36.1 104%
Empire: Total War (Medium) 51 51.4 101%
Far Cry 2 (Medium DX9) 38 40.7 107%
Left 4 Dead 2 (Very High) 43.2 43.4 100%
Mass Effect 2 (Max) 37.2 38.6 104%
STALKER: Call of Pripyat (Med. + Full Dyn.) 57.5 61.6 107%

In general, the answer is no, though we do see minor improvements of 4-7% in several titles. The biggest increase was Crysis: Warhead at 11%, but even there the difference will be difficult to notice without benchmarks.

Overall, overclocking turned out to be of little use, but we do have one final disclaimer. We're using the i7-640UM processor, which runs at 1.20GHz to a maximum Turbo speed of 2.27GHz. It's possible that the i5-520UM with its lower speed range of 1.07GHz to 1.87GHz might benefit more, but without testing we can't say for sure. We do know that on an ASUS Core i7-720QM notebook our results were similar—overclocking caused Turbo Modes to kick in less, resulting in generally lower performance—so while you can get some impressive overclocks out of i5/i7 desktop processors, in a notebook you're likely best off just going with the stock speed and Turbo Boost.

Application Performance: Arrandale ULV beats OCed CULV Battery Life Takes a Hit
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  • adonn78 - Sunday, July 11, 2010 - link

    Same crappy video card. Just a slightly faster and more expensive CPU added. Its still not enough for today's games even at the low resolution of the monitor on this notebook. They need to shrink the die on the mobile video card to get a good heat and electricity level. That way it won;t sue up too much power and will be of decent speed.
  • Jamezrp - Sunday, July 11, 2010 - link

    I've been running my own benchmarks on the M11x R2, and besides having a hell of a time with a number of the games, Optimus just doesn't seem to be ready thus yet. My scores are similar to the ones posted (close enough to make them seem right), but Optimus just doesn't seem to activate the GPU at the right times.

    For instance, it'll play for a Youtube video at 360p. I don't need that, I don't need to waste battery life there when my netbook can handle 720p without a GPU at all. Then, of course, it'll run at 1080p, but not show that it's running for the new 4K videos available on Youtube.

    I'm not impressed enough with the R2 to say it's worth a purchase, but if anything it's because of the software still being in beta, and games not supporting Optimus yet. Does this determination sound right?
  • jfmeister - Monday, July 12, 2010 - link

    The most interresting part comes at end, where you mentioned the goodies we should have had. The 2 most well awaited upgrades from v1, the LCD monitor & DX11 GPU. I was really disapointed. Would having an Radeon would have killed the battery life that much vs GT335M?

    Now the part about the 13inch model sounds tasty. It would make more sense of getting all we need in there i.e.: better LCD & GPU. Dell/Alienware, it's time to redeem yourself and jumpover the 13inch bandwagon before competition grabs the market before you. I am pretty sure they are looking around taking notes on the M11x from users & reviews to finaly create the overall "suits you best machine".

    Good point on cutting off the choices to drop down prices. On a large scale, it'll benefit the Dell & the customers.
  • buzznut - Tuesday, July 13, 2010 - link

    Hey, thanks for the great article. This addresses all my questions about my upcoming purchase. My choice is clear, I can see no reason to pay an extra $150 for optimus. Battery life is worse, and considering the CPU is faster, similar gaming performance is disappointing.

    I think I'll take my chances with the driver updates. perhaps I will invest in the return program they provide. At any rate, I'll save my 150 bucks and go with the original.
  • jaeyang9 - Sunday, July 25, 2010 - link

    i decided to splurge and got the i7, 8gb, 256gb SSD... still waiting for it to arrive... but i came across this from tutorial video from dell/alienware regarding how to *properly* use optimus for gaming or gpu intensive applications

    http://www.youtube.com/watch?v=U874jC2blJQ

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