Professional Help: Getting The Best Overclock From AMD's A8-3870K

Test System And Benchmarks

In an effort to best demonstrate multiple configurations, we first tested our system at stock frequencies using 800 MHz memory at 8-8-8-24-2T timings. Those are the same settings used in February's Llano-based overclocking story. Then, we overclocked Corsair's Vengeance kit to 933 MHz (the architecture's highest official data rate) using 9-9-9-24-29-1T timings, but kept stock CPU and GPU speeds.

We're also including a standard overclock using the same 933 MHz memory setting, changing only the CPU and GPU multipliers, but not the reference clock. This gives us 3.6 GHz processing cores and a 960 MHz GPU.

Finally, we include the highest memory overclock, a 117 MHz reference clock, 3627 MHz CPU cores, a 936 MHz GPU, and 1092 MHz (2184 MT/s DDR3) memory at 10-10-10-27-35-2T.

We're ultimately interested in how our all-out overclock compares to a discrete Radeon HD 6670 DDR3. So, we installed it in the overclocked system and disengaged its on-die GPU.

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InterfaceSocket FM1
CPU/APUAMD A8-3870K (Llano), Stock: 3.0 GHz, Overclocked To 3.627 GHz @ 1.5 V
MotherboardAsus F1A75-V Pro, Socket FM1, Chipset: AMD A75
Integrated GraphicsIntegrated Radeon HD 6550D, Stock: 600 MHz, Overclocked To 960 MHz @ 1.3 V
Discrete GraphicsRadeon HD 6670 DDR3800 MHz GPU, 900 MHz (1800 MT/s DDR3) memory
NetworkingOn-board Gigabit LAN controller
MemoryCorsair Vengeance CMZ4GX3M2A2000C102 x 2 GB, Max rating: 2000 MT/s, CL 10-10-10-27-2T,Max overclock: 2184 MT/s @ CL 10-10-10-27-2T
Hard DriveWestern Digital Caviar Black 750 GB, 7200 RPM, 32 MB Cache, SATA 3Gb/s
PowerePower EP-1200E10-T2 1200 W, ATX12V, EPS12V
Software and Drivers
Operating SystemMicrosoft Windows 7 x64
DirectXDirectX 11
Graphics DriversCatalyst 12.7 Beta
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Benchmark Configuration
3D Games
Battlefield 3Version, Operation Swordbreaker, Fraps Runs
Elder Scrolls V: SkyrimVersion, Fraps Runs
DiRT 3Version, Built-In Benchmark
StarCraft IIVersion:, Tom's Hardware Guide Benchmark
Synthetic Benchmarks
3DMark 11Version:, Benchmark Only
SiSoftware Sandra 2011Version 2011.1.17.15, CPU Test = CPU Arithmetic / MultiMedia, Memory Test = Bandwidth Benchmark
  • buzznut
    This is pretty cool, this addresses most of the questions I would have about gaming with a LLano part. But it seems Trinity is right around the corner so I would still have reservations about recommending it. Except for the fact I just saw one of these quads for $90 at the egg, which does make a compelling case for folks on a tight budget.
  • EzioAs
    Interesting read. Can't wait to see how much of an improvement the desktop Trinity APU brings seeing Llano is better than what I imagine it would be
  • esrever
    Don is the best!
  • peroludiarom
    Hi Don, you have wrote great article!
    I have just one question - do you try to overclock the memory controller as well, because its not mentioned in the article? Thanks in advance
  • mayankleoboy1
    Llano is great, but i am waiting for the die-shrink to reduce power and heat.
  • Wife's pentium intel g620 and amd 7750 on budget board and 8 gb budget ram .....only pulls 150 watts max !!!!!!!!lcost less and performs much better. Apu is a epic idea, alas still useless maybe trinity will save the day. Until then the hype and misleading performance promises will still make them money.
  • Fokissed
    On page 2 there is a reference to, which seemingly doesn't exist anymore.

    Thanks for catching that, fixed to!
  • freggo
    FokissedOn page 2 there is a reference to, which seemingly doesn't exist anymore.
    Makes you wonder how old the article is that a dead domain link made it into the text :)
  • csbeer
    "So, we installed it (6670) in the overclocked system and disengaged its on-die GPU."

    I don't get why all these major sites don't test the dual graphics nature of the asymetrical xfire that Llano supports? Marry that APU with a 6570 or 6670 for maximum performance, that's the whole point of the Llano experience imo! I have a Llano notebook and am so hungry for info on other's experiments and results with the APU+DGPU.
  • biggerbooger
    Excuse the noob question, but if you had say 2 x 4gb sticks rather than 2 x 2 and you put on a corsair H40 contained water cooler for example could you get much better OC performance? This is looking like a viable option.