Experiment: Does Intel’s Turbo Boost Trump Overclocking?

Benchmark Results: Productivity

Our Adobe Photoshop CS4 benchmark consists of several threaded filters applied to a .tif image. It’s little surprise, then, that Turbo Boost has a minimal effect here. Hyper-Threading doesn’t seem to do much either.

What really does help boost performance in Photoshop CS4 is clock rate. The Core i7-860 at 2.8 GHz does a bit better than the Core i5-750 at 2.66 GHz, while Turbo Boost enabled adds 133 MHz to both chips. Then, at 4 GHz, they both turn in comparable numbers, which are significantly quicker than the non-overclocked scores.

We’ve been perplexed by the behavior of AVG 9, which hasn’t scaled well at all since we upgraded from AVG 8.5. However, simply running the task manager as this test executes tells the tale. As the scanner runs, it’s only consuming, at most, 10% of the processor’s resources. We tested across dual-core chips and Atom-based platforms—performance does slow down as you take execution cores away and drop clock rate. However, the Core i5-750 and Core i7-860 are similar enough that their performances in AVG 9 are virtually identical.

3ds Max 2010 enjoys a benefit from both Hyper-Threading and Turbo Boost technology. Overclocking remains the best way to maximize your experience in this title though. The Core i5-750 even enjoys a slight advantage at 4 GHz via its 200 MHz BCLK, which is 10 MHz higher than the i7-860’s 190 MHz setting.

Known to be threaded (but clearly not optimized for Hyper-Threading), WinRAR gets a minimal speed-up from Turbo Boost technology since all four of its cores are active. Turning Turbo Boost off completely backs the speed of each CPU down by 133 MHz when they’re fully utilized, which is why Turbo Boost appears to help somewhat.

When both chips are dialed in to 4 GHz, though, performance is comparable (and significantly faster than stock settings).

Another test we’ve added based on popular demand, 7zip is also freely available and well-optimized for today’s processor architectures.

As we can see, the compression speed (in KB/s) scales not only to clock rate, but also available cores. In fact, the Core i5-750 at 4 GHz isn’t even able to match the Core i7-860 at 2.8 GHz with Turbo Boost disabled.

Because this title is well-threaded, Turbo adds very little to the bottom-line. Hyper-Threading adds quite a bit of performance, and overclocking once again shows a serious win.

Chris Angelini
Chris Angelini is an Editor Emeritus at Tom's Hardware US. He edits hardware reviews and covers high-profile CPU and GPU launches.
  • phantomtrooper
    No one needs a Core i7 for gaming. I'm still using a e8400 with a gtx275 and I run everything fine at 1080p, even Crysis.
  • apache_lives
    i play GTAIV online alot - your e8400 gets left in the dust there sorry PhantomTrooper, and theres no adverse effects having spare cores for future use with newer games etc
  • dtemple
    I second that, PhantomTrooper. I'm on a slightly lower end spec PC than you're using (Athlon 7750 with Radeon HD4830) and with it hooked up to my 1366x768 TV through VGA, everything I play maxes without lag. Mind you, I don't play any titles that are extremely demanding, but I'm playing 2008 and 2009 titles maxed out, on a $60 CPU and an $80 video card.
  • curnel_D
    Great article. On another note, the useless Mass Effect 2 ad blaring it's stupid music in my ears at every new page is really starting to piss me off.
  • cangelini
    Yeah, you guys are going to get a kick out of the upcoming Clarksdale story. It's amazing how badly a Core 2 Duo E8500 gets killed by a Phenom II X4 or Core 2 Quad in some of these more optimized titles.

    Curnel--sorry about the ad. I also find it pretty annoying to play automatically every time I open a page for proofing. I'll ask about it.
  • jj463rd
    Nice article.I agree about the annoying video ads that Curnel_D mentioned earlier.
  • HansVonOhain
    Curnel_DGreat article. On another note, the useless Mass Effect 2 ad blaring it's stupid music in my ears at every new page is really starting to piss me off.
    Thanks Chris for your courtesy.
  • descendency
    Curnel_DGreat article. On another note, the useless Mass Effect 2 ad blaring it's stupid music in my ears at every new page is really starting to piss me off.I know it's not a viable solution for all, but I never have my sound on... so I didn't even notice the advert (other than seeing it.)
  • gilbertfh
    I have been building computers for myself family and friends for years and I remember some of the different ways utilized to speed up your computer (including the turbo button on your computer). This method seems like a viable way to speed up computers of those of us that don't really want to overclock.

    On a side note: Woot!!! I just saw the Mass Effect 2 ad has been removed. It did have the option to mute it but it was removed fast enough I didn't have a chance to check to ensure it saved to all pages. Thanks Tom's.
  • gilbertfh
    Nope I was wrong I guess it was random and just didn't come up for a while and the mute does not save :(.