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

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67 Comments

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.

Interface
Socket FM1
CPU/APU
AMD A8-3870K (Llano), Stock: 3.0 GHz,
Overclocked To 3.627 GHz @ 1.5 V
Motherboard
Asus 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 DDR3
800 MHz GPU, 900 MHz (1800 MT/s DDR3) memory
Networking
On-board Gigabit LAN controller
Memory
Corsair Vengeance CMZ4GX3M2A2000C10
2 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 Drive
Western Digital Caviar Black 750 GB, 7200 RPM, 32 MB Cache, SATA 3Gb/s
Power
ePower EP-1200E10-T2 1200 W, ATX12V, EPS12V
Software and Drivers
Operating System
Microsoft Windows 7 x64
DirectX
DirectX 11
Graphics Drivers
Catalyst 12.7 Beta
Benchmark Configuration
3D Games
Battlefield 3
Version 1.0.0.0, Operation Swordbreaker, Fraps Runs
Elder Scrolls V: Skyrim
Version 1.4.21.04, Fraps Runs
DiRT 3
Version 1.2.0.0, Built-In Benchmark
StarCraft II
Version: 1.4.2.20141, Tom's Hardware Guide Benchmark
Synthetic Benchmarks
3DMark 11Version: 1.0.1.0, Benchmark Only
SiSoftware Sandra 2011Version 2011.1.17.15, CPU Test = CPU Arithmetic / MultiMedia, Memory Test = Bandwidth Benchmark
Previous Next
Summary
  1. Sami Mäkinen Weighs In On Llano Overclocking
  2. Dialing In Our Overclock Using The Right Components
  3. Test System And Benchmarks
  4. Benchmark Results: Synthetics
  5. Benchmark Results: The Elder Scrolls V: Skyrim
  6. Benchmark Results: Battlefield 3
  7. Benchmark Results: DiRT 3
  8. Benchmark Results: StarCraft II
  9. Power And Temperature
  10. AMD A8-3870K: Coming Close To Radeon HD 6670
About the author
Don Woligroski
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  • 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
    • Other Comments
  • 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.
  • Anonymous
    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 hwbot.com, which seemingly doesn't exist anymore.

    [EDIT BY CLEEVE] Thanks for catching that, fixed to hwbot.org! [/EDIT]
  • freggo
    FokissedOn page 2 there is a reference to hwbot.com, 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.
  • serendipiti
    Good article, a bit late (and excuse my paranoia, but having AMD stopped trinity just to end selling A8s in stock makes me think this article comes as an ad...)

    Snow85Wife'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.


    I don't think it is fair to compare. OK, both are products on the market, but it's not fair. g620 is in fact a marketing item, is a modern intel processor capped down... I would better compare Phenom II + 6670, but comparing AMD and Intel it is not a fair comparison for the APU concept. I don't mean your buying decision should take into account g620...

    Moore's law takes us there: it makes no sense a 32 core cpu on a desktop PC by now, but it makes a lot of sense having a SoC, and getting the desktop PC fit your palm...

    The first APU attempts show lot of binding to memory performance... so 3 / 4 channel architectures should improve a lot the result, the problem is that 2 more channels mean lots of pins on the socket, which rise costs...

    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.


    I think the first benchmarks tested that combination...
  • vitornob
    serendipitiGood article, a bit late (and excuse my paranoia, but having AMD stopped trinity just to end selling A8s in stock makes me think this article comes as an ad...)I don't think it is fair to compare. OK, both are products on the market, but it's not fair. g620 is in fact a marketing item, is a modern intel processor capped down... I would better compare Phenom II + 6670, but comparing AMD and Intel it is not a fair comparison for the APU concept. I don't mean your buying decision should take into account g620...Moore's law takes us there: it makes no sense a 32 core cpu on a desktop PC by now, but it makes a lot of sense having a SoC, and getting the desktop PC fit your palm... The first APU attempts show lot of binding to memory performance... so 3 / 4 channel architectures should improve a lot the result, the problem is that 2 more channels mean lots of pins on the socket, which rise costs... I think the first benchmarks tested that combination...


    Don't see how this is an unfair comparative. (A8-3870k vs G620 + HD7750)
    Both will serve as CPU, both will serve as GPU, both are in the market. In the PC components market we should look for 3 mainly caracteristics:
    1- Performance on the softwares you use (this include reability and warranty)
    2- Cost of the parts
    3- And a few years to now, energy usage

    If Snow85 is right in his statements, we have the combo g620 + HD7750 being, cheaper, faster and using less energy.
    So.. where's the unfair here? Doesn't both in the same market, being sold for the same people that looks for components?
  • A Bad Day
    *Looks at AMD Trinity*

    *Notices that the laptop has a 1066 MHz memory with 9-9-9-x timing*

    Hey manufacturer, why not get a cheaper Trinity and spend a little more on a 1600 or 1866 MHz memory? Oh wait, marketing.
  • Lutfij
    good read.
  • Onus
    Interesting exercise, especially for those who like to play with their hardware. For those wanting to play on their hardware, there are better choices. I used to be in the first group, but now I'm in the second, although some of the tips here are certainly useful.
    I also thought it was funny how the pic of the CM cooler showed it with the Intel pushpins, not the AMD FM1 mounting bracket.
  • gondor
    mayankleoboy1Llano is great, but i am waiting for the die-shrink to reduce power and heat.


    LOL !? Llano *is* a die shrink of K10.5 CPU architecture (formerly at 45 nm) and VLIW5 GPU architecture formerly at 40 nm) down to 32 nm. There aren't going to be any more K10.5 die shrinks, it's a dead architecture for the time being.
  • tului
    Snow85Wife'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.

    In a laptop, where you can't pop in discrete graphics, it is another story. You can easily get a $500 system that can game nearly as well as some $1000 systems(especially the ones with crap Intel HD 3000/4000 crap). If I'm paying $1000+ for a laptop, it'd better have a discrete GPU. At $500 and below, the APU is a great price in that form factor.

    You are right on the desktop though, where you can get much higher per core and per watt performance for x86 out of Intel and just slap in a $80 GPU if or when you need to take graphics up a notch.
  • beavermml
    this APU is very good on the laptop.. but can we OCed on laptop?
  • serendipiti
    vitornobDon't see how this is an unfair comparative. (A8-3870k vs G620 + HD7750)Both will serve as CPU, both will serve as GPU, both are in the market. In the PC components market we should look for 3 mainly caracteristics: 1- Performance on the softwares you use (this include reability and warranty)2- Cost of the parts3- And a few years to now, energy usageIf Snow85 is right in his statements, we have the combo g620 + HD7750 being, cheaper, faster and using less energy.So.. where's the unfair here? Doesn't both in the same market, being sold for the same people that looks for components?


    It's unfair if you want to test about the APU concept. it's about asking if it makes sense to integrate the GPU with the CPU to get an APU...
    My point of view it is not about to compare products to perform a purchase decision. Making a purchase decision has to do with the concrete situation you are dealing with (and here, every case may be a different one, with different things to look at. Anyway, comparing the energy usage on such a heavily overclocked-overvolted chip is useless, without OC, the A8 is hard to beat on energy usage...)
    My point of view is about trends and comparing technology... For this reason I talked about a 32 core CPU vs SoC and their uses in the current days.
  • vitornob
    serendipitiIt's unfair if you want to test about the APU concept. it's about asking if it makes sense to integrate the GPU with the CPU to get an APU... My point of view it is not about to compare products to perform a purchase decision. Making a purchase decision has to do with the concrete situation you are dealing with (and here, every case may be a different one, with different things to look at. Anyway, comparing the energy usage on such a heavily overclocked-overvolted chip is useless, without OC, the A8 is hard to beat on energy usage...)My point of view is about trends and comparing technology... For this reason I talked about a 32 core CPU vs SoC and their uses in the current days.


    Now sir I agree 100%.. trend by trend, AMD APUs are unique
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