AMD Phenom II X4 940 & 920: A True Return to Competition
by Anand Lal Shimpi on January 8, 2009 12:00 AM EST- Posted in
- CPUs
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.
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Beno - Monday, January 12, 2009 - link
fanboys help keep them alive.if more ppl started looking at AMD again, then Intel will be scared, so us the consumers will be happy because of prices.
intel has been greedy and overpriced their c2 because there was no competetion at that time.
garydale - Friday, January 9, 2009 - link
I generally buy AMD processors for two reasons. The first is that I am not a gamer so I'm looking for cost-effective business application solutions. I'd rather double the memory than increase the processor speed, so AMD works well at the price points I build to.Secondly, I believe in the need for competition. With the power PC processor virtually absent from the consumer market and there being little else to choose from for the desktop market, AMD is Intel's only real competitor. So long as AMD has chips that are good enough to compete with Intel's on price/performance, I prefer to buy them.
If Via got their Cyrix processors up to a decent speed, I might be tempted to switch to them, but let's face it, they don't really compete in this market. So in a two-way race, we need to put our money behind the underdog to prevent a monopoly.
I've been buying ATI cards too for similar reasons. Nice to see that AMD's making advances in both areas.
To be clear, I've got nothing against Intel, at least not since the Pentium fiasco, but I think everyone will agree that having multiple firms competing is better for consumers than having one company dominate (Windows 95, 98, Millenium Edition, Vista come to mind). :)
aeternitas - Friday, January 9, 2009 - link
Much of your post should go next to the Webster definition of "AMDfanboi"If you want true competition, buy the better product. I got my sweet A64. I will now consider P2 over a C2D, but because of price/performance/watt alone.
Certified partner - Friday, January 9, 2009 - link
"Blender is one of the few tests that doesn't strongly favor the Core i7, in fact it does not favor them at all. Here the Core 2 Quad Q9650 is the fastest processor, followed by the Phenom II X4 940 and the Phenom II X4 920."http://www.techspot.com/review/137-amd-phenom2-x4-...">http://www.techspot.com/review/137-amd-phenom2-x4-...
"Blender shows Phenom II less competitive than the other 3D rendering tests we've seen thus far."
http://www.anandtech.com/cpuchipsets/showdoc.aspx?...">http://www.anandtech.com/cpuchipsets/showdoc.aspx?...
Both can't be true. Explanations would be highly appreciated. I suggest, that anandtech ask techspot about the test settings. Blender is capable of using several threads but I'm not sure wether the optimization is automated. Please, play with the settings. For example, 8*8 (render) tiles can benefit from 8 threads while 1*1 can't.
Max1 - Friday, January 9, 2009 - link
How much money has paid Intel to you for this "testing"? You have tested productivity of processors only on two games. In both games productivity of Core 2 is above. In one of them much more above, but it happens seldom. Other tests show, that productivity of Core 2 Quad in part of games is above. In part of games productivity Phenom II of same frequency is above. Why there is so a lot of coding and synthetic tests where Intel is faster, and as always there are no other applications? Why you continue to say lies, as earlier liars for money of Intel that Northwood is ostensibly faster, than Barton.strikeback03 - Friday, January 9, 2009 - link
I'm surprised how long it took the fanbois to start commenting on this article. Didn't really get rolling until several pages into the comments.JimmiG - Friday, January 9, 2009 - link
Bit disappointing that it's still slower than Core2 clock for clock. But given the performance of the original Phenom, I think the CPU performs as expected. A big leap for AMD. Unfortunately for them, Intel made an even bigger leap when they switched from Netbust to Core2.Also a bit concerned about this supposed "backwards compatibility". Many of the original 790FX boards, my M3A32-MVP Deluxe in particular, will not work with AM3 CPUs because Asus does not plan on releasing a BIOS update. Of course that's the fault of second-rate mobo companies like Asus, and not the fault of AMD. I'll probably end up getting a DDR2 PII-940 to replace my X4 9650, but I'll wait until the prices have dropped some.
anandtech02148 - Friday, January 9, 2009 - link
Just wait till Am3 socket comes out, Intel will have to make a slight cheaper version of x58chipset. Is that sweat i see on their forehead?Amd buy Via's Nano and give them a 2 prong attack.
RogueAdmin - Friday, January 9, 2009 - link
AMD has gone a long way to improving the performance of its processors, and everyone should go out and buy them. They need our support, and without it we will have to put up with whatever Intel decide to give us. And everyone here I think remembers the P4 days, let them not come again!The AM2 /2+ /3 platform is by far the easiest upgrade option. No need to worry if your NB chipset supports the latest FSB or RAM, because its all integrated into the CPU. A feature than Intel has copied in its new i7. Along with the monlithic quad core design, and level 3 cache. Also do not forget that AMD released the first x86-64 CPU, and intel basically complied to its x86-64 code to be compatible with the software developed for it.
i7 is fast, very fast. But do you need that kind of performance in your everyday life? i7 is designed for workstation's hence the benchmarks of video encoding and 3D applications. Gamers would be better off getting a top of the line GPU. Is your CPU 100% utilized 24/7?
I saw a comment about the 2 year old Core 2 Quad being faster, only in Far Cry 2, that one test. And I would rather play Crysis anyday.
Since its release Intel has tweaked the performance of these with new cores no end.
Sorry I digest.... lol
Keep things competitive, buy AMD. Fanboy or no, let the price wars rage on.
aeternitas - Friday, January 9, 2009 - link
1. Most people use their everyday system to *work* too.2. Dont compare i7 to P2. Youll just look like youre really reaching and a fanboy.
3. You dont -Need- anything better than a A64 for everyday tasks. Depending on how long you wanna wait though, you will go to a better system. That point about not -needing- better hardware has always been ridiculous and only applies to grandmas and people that use the computer for browsing and music. Those people dont care about this area in computer so its moot!
P2 is great, but be realistic. Its competing against C2 right now. Comparing technicalities and -who was firsts- doesnt provide more FPs in anything. It just makes for flame fodder. The numbers speak for themselves and I think this article did a good job in putting the P2 in its place. As a great alternative for people looking to upgrade from older than C2 hardware.