Core i5-3570K, -3550, -3550S, And -3570T: Ivy Bridge Efficiency

Four Ivy Bridge-Based Core i5 CPUs, Compared

Intel made low-power processors really interesting a few years back by launching a couple of 65 W Core 2 Quads that offered the same performance as its 95 W models. Sure, you had to pay quite a bit more for the privilege of owning one. But the idea of slipping an extra-cool chip into a diminutive desktop or home theater machine made the premium a worthwhile consideration.

Once the company introduced its Nehalem architecture, it was able to more easily exploit available thermal headroom using Turbo Boost. By increasing clock rate according to workload, Intel didn’t leave as much performance on the table. A 3 GHz CPU, for example, could be made to run at 3.4 or 3.5 GHz when only one of its cores was active, operating faster (and hotter) with the ultimate goal of dropping back to idle sooner.

It then debuted power-optimized versions of its CPUs based on the Lynnfield design. But instead of dropping TDP and maintaining performance, the company was forced to cut its base clocks and scale back Turbo Boosted frequencies in an effort to keep power down. Even as Intel gave you less performance, it continued charging more for those S-family models in a double-blow to value. We quickly called the company out in Intel Core i5-750S: Since When Does The S Mean Slow?

The company countered our criticism by claiming the “power-optimized” models were conceptualized as complements to the dual-core Clarkdale-based CPUs. Core i5-750S was supposed to be the first quad-core Nehalem-based model able to fit within an 82 W TDP. That didn’t justify charging more for it, we answered back.

And apparently, Intel heard us. Its new Ivy Bridge-based desktop line-up consists of 14 models. Seven of those are low-power SKUs, and none of them cost more than the standard versions. Instead, Intel charges the same price, asking only that you choose between more speed and lower power.

That’s a decision we can live with because, for most of us, the vanilla 77 W models already represent a significant savings over last generation’s 95 W Sandy Bridge flagships. Choosing higher-performing third-gen Core chips becomes almost universal.

What if you’re a system builder and you need a guarantee that your Ivy Bridge-based processor won’t exceed 65 or even 45 W, though? That’s an entirely legitimate concern, particularly as the all-in-one form factor picks up steam. In that case, you simply have to give up a little speed and go with the –S- or –T-class parts.

We got our hands on a number of Core i5s to complement our coverage of Ivy Bridge in Intel Core i7-3770K Review: A Small Step Up For Ivy Bridge, including two 77 W samples, one 65 W Core i5-3550S and a 45 W Core i5-3570T. The plan is to run all four i5s through our benchmark suite to gauge the impact of scaling down power on performance, and then to determine if the slower “optimized” chips are any more efficient.

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.
  • zyzz
    Good article. I think I will get the 3570K over 2500K.
    Reply
  • erraticfocus
    nice work in sorting out the facts and reminding us about the history and change from the lower power offerings in the intel stable..

    Reply
  • amdfangirl
    Does Intel allow underclocking and undervolting on H-series boards? If so, S and T series are pretty redundant.
    Reply
  • Onikage
    2700K looks a clear Winner to me ! got one last week from Microcenter at an ironic but sensational price 270$ !!!! hey 3770K try and beat that !
    Reply
  • Outlander_04
    In the real world gaming section you got a great big graph for the 3770k by adding a discreet graphics card . Why didn't you try a Llano system with an identical graphics card? Afraid the second tier AMD product would kick sand in intels face?
    Reply
  • cangelini
    Outlander_04In the real world gaming section you got a great big graph for the 3770k by adding a discreet graphics card . Why didn't you try a Llano system with an identical graphics card? Afraid the second tier AMD product would kick sand in intels face?Because this is a story about the Intel chips. To the contrary, though, the AMD-based platform is more likely to bottleneck a discrete graphics card than the Intel one. AMD's strength is in the integrated graphics right now.
    Reply
  • Outlander_04
    The performance of a Llano chip is included in the article to compare its performance so it not just about intel cpu's . The intels were not as good in gaming in the integrated graphics so a graphics card was added so they'd look better there too . Its an unfair comparison and shows intel bias IMO
    Reply
  • jimmysmitty
    Outlander_04The performance of a Llano chip is included in the article to compare its performance so it not just about intel cpu's . The intels were not as good in gaming in the integrated graphics so a graphics card was added so they'd look better there too . Its an unfair comparison and shows intel bias IMO
    Actually a lot of sites have shown just what Chris is talking about. Even a dual core Pentium with a HD6670 beats the top end Llano piece (a quad core) even with CFX of the IGP with a HD6570. Llano is great for some things but overall in DT its only a low end entry level product and is much weaker per core and per clock than Intels CPUs.

    What Chris did was pulled the same charts from his first IB review and added in the HD2500 (the new low end Intel IGP) for comparison.

    If someone cannot take this information and realize that its just for comparison and that its not to show anything better, then thats their problem. If this was a Llano article, or the Trinity article when it comes out, you better believe Chris will do everything to check ever performance aspect. But its not. Its an article to see if the T and S models are worth it.

    Overll, llano is overrate in my book. We have barley sold any at my work place. Just doesn't have the pulling power like a CPU and discrete GPU does.
    Reply
  • GhosT94
    should have compared the Core i5-3570K vs the Core i5-2500K
    Reply
  • Outlander_04
    If you are going to show the performance of an intel cpu with a graphics card then any reasonable comparison would also show the AMD cpu with the same graphics card .
    Reply