Hooray, AMD is Overclockable Again

Since the introduction of the B3 stepping Phenom that solved the TLB bug (along with improved yields), overclocking a Phenom has been a fairly painless process. This is especially true with the Black Edition series and a well designed motherboard based on the 790FX, 790GX, or 780a chipsets. While the Phenom has not offered the same overclocking headroom as the latest Penryn processors that typically offer a 1GHz improvement on the middle to upper range processors with air-cooling, it is not uncommon to see the Phenom BE series offering a 600~800MHz improvement in clock speeds.

AMD has proven in early demonstrations that the Phenom II x4 will offer overclocking headroom similar to the Penryn series. Early production sample processors have clocked anywhere from 3.9GHz on air to 4.4GHz on water and all the way up to 6.3GHz on LN2. We have matched their results on air-cooling and been impressed with the potential headroom offered by the new 45nm manufacturing process on extreme cooling setups. In fact, the latest retail steppings that AMD displayed this past week showed significant improvements in overclocking headroom compared to the press samples we utilized. Our 940 topped out at 3.9GHz, which is not bad, but after reviewing AMD’s results and seeing some early retail numbers on the forums, the expectation level for air-cooling is now set to the 4.1GHz range with the 920 hitting 3.8~3.9GHz on the right motherboard.

We have retail processors arriving shortly for additional overclocking tests (we will push HTT/NB settings); in the meantime, we have some interesting numbers to present with our press samples. In our overclocking tests today we are utilizing the Phenom II X4 940, Phenom 9950 Black Edition 125W, Core 2 Q9550, and the Core i7 920. Besides having a strong processor, a well-engineered motherboard, premium memory, excellent cooling, and proper power supply are all essential elements in obtaining stable and high clock speeds when overclocking.

With that in mind, we are utilizing the DFI LP DK 790FXB-M2RSH (790FX), ASUS Maximus II Formula (P45), and DFI LP UT X58-T3eH8 (X58) motherboards for testing. We also tossed in the Corsair HX1000 power supply along with memory from Corsair and G.Skill featuring their TR3XGG1600C8D 6GB DDR3-1600 and F2-8800CL5D-4GBPI DDR2-1100 4GB kits respectively. The balance of the test system consists of a WD Caviar Black 1TB HD, Blu-ray drives from Sony and LG, Vista 64 Ultimate, and our ABS Canyon 695 case.

In a twist from our normal overclocking results, we decided to utilize the retail air-coolers from Intel and AMD to provide a more realistic out-of-box experience when overclocking. We based today’s test results on how high we could overclock on stock voltages and then by increasing voltages until we ran out of cooling headroom with the retail coolers.

Processor Highest Overclock (Stock Voltage) Highest Overclock (Overvolted) % Increase over stock Overvolted Vcore
AMD Phenom II X4 940 (3.0GHz - 1.32V) 3.2GHz 3.9GHz 30% 1.52V
AMD Phenom 9950 BE (2.6GHz - 1.26V) 3.03GHz 3.38GHz 30% 1.45V
Intel Core i7-920 (2.66GHz - 1.32V) 3.83GHz 4.0GHz 50% 1.35V
Intel Core 2 Quad Q9550 (2.86GHz - 1.22V) 3.48GHz 3.91GHz 38% 1.35V

We disabled the power management features and manually set the voltages to stock values. Leaving the BIOS settings at Auto will generally result in the BIOS auto-leveling voltages to handle the increased clock speeds for the processor, memory, and bus speeds. We did not get very far with our particular 940 sample as it only reached 3.2GHz resulting in a dismal 7% increase in clock speed. With the exception of the PCMark Vantage TV/Movies test suite and our Flight Simulator X benchmark, this 940 processor passed all other tests at 3.45GHz. The Phenom 9950BE had a 17% increase in clock speed while the i7 920 managed a stunning 50% improvement in clock speed. The E0 stepping Q9550 managed a 23% improvement in core speed.

In our second test, we manipulate voltage settings ranging from the normal VCore/VDimm to VTT/IOH/PCIe until we reached the load limits on the retail air-coolers. Higher-end air-coolers improved clock speeds slightly (3~5%) while dropping core temperatures up to 9C in certain cases.

The clocking situation improved greatly with our 940 once VCore rose to a final 1.52V. We actually hit 4GHz but needed 1.58V to do it. This resulted in a few crashes due to temperatures, but we also noticed our particular CPU sample just was not stable at 4GHz+ even with additional voltages and cooling. The results for the two Intel processors are simply superb in this particular test with the 9950BE managing a respectable 30% improvement in clock speeds, matching that of the Phemom II percentage wise.

Phenom vs. Phenom II - Clock for Clock The Test
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  • Walkeer - Thursday, October 15, 2009 - link

    Super, so because MS Vista has a really bad and stupid CPU scheduler, AMD had to disable perfectly legit and smart power saving feature = CnC per core rather than per chip. I really love windows! I expect that CnC per-core caused no problems under linux for example....
  • CuE0083 - Sunday, April 26, 2009 - link

    I have been a reader of this site for a few years (first time commenting) and I just wanted to know how you guys determine that a particular processor is a good overclocker.

    1) Do you guys try overclocking multiple chips?
    2) Do you just walk into the store, pick a random chip, and try overclocking it?
    3) Or does AMD send you a chip?
  • v12v12 - Thursday, July 23, 2009 - link

    All this bickering and nick picking—when to me the solution seems simple.

    All the poor folks clamoring about numbers they COULD NOT EVER POSSIBLY tell the difference if using Intel Vs AMD in a dboule-blind test! None of you can tell the measurable diffs in FPS and temp. It's all little programs with numbers telling you there's a difference. So wtf is all the fus about?

    Phenom-II is for people that already have an old AM2 rig and want to upgrade. But you forget that your old, slow ass mobo chipset and antiquated ram wouldn't even come close of a newer Intel system period.
    A Brand NEW Phenom-II would "compete," but it barely does that. And as prices drop Phenom-II is losing even more ground as someone with an intel 775 can spring for a fast Quad-core, while you're stuck with the SAME OLD MOBO and RAM DERRRRR?
    Stop all the nit-picking and bemoaning over Intel.

    Does it make sense to scrap your current AMD rig for a completely new Intel unit?

    YES = If you're doing video/AV editing and plan on getting an i7/i5 or if you’re not broke!

    NO = If you currently have an AMD and need some extra horse-power.

    But to falsely rationalize your purchase/mindset by suddenly putting the i7 into the "it's SO expensive" BS category; you're BROKE, you have no say about price. Get a real job and stop spending money on other nonsense and SAVE up like smart people do. It's YOUR own fault you cannot afford a damn $1100-1400 computer: that's NOT a lot. Just b/c YOU cannot afford it doesn't mean there's something "wrong" with i7.

    You're comparing a 2yr old Q6600 against AMD's newest unit LOL? That's like a car magazine comparing the newest lambo to a 2 year old Ferrari etc. BUT PRICE OMG... Prices steadily go DOWN, thus folks with 775 can still upgrade to 6700, 6800 and so forth.

    I'm glad AMD is "sort of" showing a rally to CATCH UP... BUT... when you buy into INTEL you're buying into a PROVEN ROADMAP OF PERFORMANCE VS AMD: you're buying into a mystery grab-bag of performance PROMISES.

    Geesh. Just get the Phenom-II if you cannot afford the i7. Nobody with sense is talking about going from a Q6600/9xxx to 2 year behind the pack Phenom. This is just sophomoric nonsense.

    Common-sense would tell you:

    1) GET A BETTER JOB (education/certs etc)

    2) Stop spending money on other hobbies and misc junk

    3) STFU already and improve your financial situation, THEN you have a say. It's YOUR fault you don't have enough for a paltry $1200 machine. WHO doesn't have $1200? If you don't you haven't EARNED the right to complain. Complain b/c it's someone else's fault - I'm betting it's mostly your own lack of saving & discipline that's the problem.

    None of you may like or agree w/me, but guess what? I don't care b/c I HAVE $1200 to spend so Fsck it I'm happy. Stop drinking, doing drugs, going out, blowing money on cable-TV and crap, for a change? Most of you are guilty of 1 or more of these frivolities.

    Honestly THINK about what you’re saying here? You’re complaining about a superior i7 that is too expensive to do WHAT— play some damn video games? So your rationale is to do what? Buy a new or CPU upgrade to do the same? So THUS instead of continually saving to get the best… You BLOW your loads for inferior technology… and so the cycle continues. You’re NOW BROKE AGAIN and behind. Maybe you’ll start saving once again and come out of the wood work 2-3yrs later and STILL be complain once again “OMG it’s TOO EXPENSIVE” “I’ll by the cheap crap instead!”

    LMFAO NOW THAT IS Ludicrous!
  • goofbud - Tuesday, December 6, 2011 - link

    Are you serious dude?

    It ain't the money. I know. I have money. I also have a lambo a porche and an evo. I like testing AMD because they give us "certified" techs something to tinker with and work on. AMD is a brand for builders and true techs like to tinker with a processor and see how far it can go. Even when I was in high school I owned 486's which were the latest and greatest that time. I had an INTEL PC and it sucked dirt once Microsoft came out with windows. Maybe Intel is ahead now but AMD is catching up. They can create the ultimate processor but they don't have to. Not yet.

    BTW, watch how you talk. Be considerate. It ain't the money man. I can afford to buy as many alienware pc's I want. But I don't. Am I a gamer? Yes! I have a powerful system now and am happy I did not spend a lot of money on it. See, this is the thing. If you are smart you just don't want to buy the fastest CPU and fastest RAM that comes out. It's like buying an PS3 for $6,000.00 on ebay just because you want to be the first to play it. That is stupid.

    People buy AMD because they are tweakable. They try to buy the cheapest parts out there, tweak it, and see how far it can go. Makes sense?

    So what if you have the fastest computer in the world. If you don't use it everyday you just wasted money.

    Understand now kid. Now STFU and Go to your room!
  • sandstones - Wednesday, March 25, 2009 - link

    I know that we should look at relative sysmark scores, but I'm still puzzled by the higher scores in this batch of tests, compared to those done in April 2008.

    For example the top performer from April - Core 2 Duo E8400 got a score of 161 on Overall in April 2008, and 191 in Jan 2009. The X4 Phenom 9750 went from 126 to 148. Other CPU's in both tests had similar differences. That's a bigger percentage difference than what gets used to debate whether Intel or AMD is better.

    Anand - any comments on what caused such a large difference?
  • Amitjakhar - Friday, February 20, 2009 - link

    After overclocking it really comes near and sometime it gets better performance them Core i7. Which is good. AMD has done superb job and they are in the right direction. Next black edition will make Intel so worry they have to go to work again.
  • Amitjakhar - Friday, February 20, 2009 - link

    Phenom II is showing power much better then here. To me it seems they have not done the testing properly. You better check out this link and find how its performing genuinely
  • salem80 - Tuesday, January 27, 2009 - link

    The Q9400 are 126W~174W not like what Intel said 95W ?
    even E8600 (124W~157W) while they say 65W ?
    their huge deferent in numbers here .
  • pcuser123 - Saturday, January 24, 2009 - link

    I think the new i7 core sucks compare Phenom II. Just look at the pricing vs performance on those two.
    Here is the benchmarks http://www.overclockersclub.com/reviews/phenomii94...">http://www.overclockersclub.com/reviews/phenomii94...
  • gipper - Monday, January 19, 2009 - link

    You do the overclocks but don't show us the results? Following overclocking, those stock processors have WIDELY different capabilities.

    I'd love to see those video encode charts redone with the overclocked processors. That would tell me the TRUE value of the 64x2BE, C2D, Phenom, PhenomII, and i7 relative to one another.

    Otherwise, your overclock information borders on worthless.

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