AMD Phenom II X4 940 Black Edition (BE)
Although there are multiple AMD Phenom II choices, we used the Phenom II X4 940 for several reasons. We did not want to use the first-generation Phenom, as it is still based on AMD’s 65 nm manufacturing technology, which cannot compete with the more advanced 45 nm Phenom II when it comes to performance and the best efficiency.
The Phenom II X4 940 Black Edition running at 3 GHz is the fastest model with an unlocked multiplier, which facilitates multiplier adjustments both upward and downward. This allowed us to simulate the Phenom II X4 920 that runs at 2.8 GHz. We will provide the same type of testing with an Intel Core i7 920 system in the days to come. In that case, we chose the entry-level i7 920 in an effort stay away from the faster models that are significantly more expensive. In the case of AMD, even the Phenom II X4 940 isn’t really pricey, so that wasn't as much of a concern.
Phenom II Models
The Phenom II X4 is a modern, high-end desktop processor that is largely a result of AMD switching from 65 nm to 45 nm manufacturing. It increases the shared L3 cache capacity from 2 MB on Phenom CPUs to 4 MB (Socket AM3 models) or even 6 MB (socket AM2+ models).
The die size of all Phenom II models is 285 mm², although the effective cache configuration may vary to increase production yields. In a simple example, a quad-core die with a faulty core can still be modified and sold as a triple-core model. The following table lists all available Phenom II X4 quad-core processors:
| Phenom II X4 Model | Platform | Clock Speed | Cores | L2 Cache | L3 Cache | TDP |
|---|---|---|---|---|---|---|
| 940 | Socket AM2+ (DDR2) | 3.0 GHz | 4 | 512 KB per Core (2 MB total) | 6 MB shared | 125 W |
| 920 | Socket AM2+ (DDR2) | 2.8 GHz | 4 | 512 KB per Core (2 MB total) | 6 MB shared | 125 W |
| 910 | Socket AM3 (DDR3) | 2.6 GHz | 4 | 512 KB per Core (2 MB total) | 6 MB shared | 95 W |
| 810 | Socket AM3 (DDR3) | 2.6 GHz | 4 | 512 KB per Core (2 MB total) | 4 MB shared | 95 W |
| 805 | Socket AM3 (DDR3) | 2.5 GHz | 4 | 512 KB per Core (2 MB total) | 4 MB shared | 95 W |
The following table lists available triple-core Phenom II X3 CPUs:
| Phenom II X3 Model | Platform | Clock Speed | Cores | L2 Cache | L3 Cache | TDP |
|---|---|---|---|---|---|---|
| 720 | Socket AM3 (DDR3) | 2.8 GHz | 3 | 512 KB per Core (1.5 MB total) | 6 MB Shared | 95 W |
| 710 | Socket AM3 (DDR3) | 2.6 GHz | 3 | 512 KB per Core (1.5 MB total) | 6 MB Shared | 95 W |
Processor Flexibility
AMD processors still employ Hyper Transport to link to the system chipset, and they still include a dual-channel memory controller. AMD decided to offer 45 nm Phenom II processors supporting DDR2 and DDR3 memory, and those CPUs are technically based on the same technology.
Socket AM2+ is the latest interface for AMD’s DDR2-based processors. Hence, all AM2+ motherboards will support processors that were designed for this 940-pin socket as long as the motherboard offers BIOS support for the particular model.
The new processors with DDR3 memory controllers build-in require socket AM3, which is a modified version of the same, physical 940-pin socket designed to support DDR3 memory. The neat part of this strategy is that it is possible to purchase a Socket AM3-based Phenom II processor and run it on a socket AM2+ system with DDR2 memory. At the same time, it is not possible to “upgrade” an AM2+-based Phenom II processor to run on a Socket AM3, as the socket utilizes only 938 instead of 940 pins.
Power And Overclocking
All Phenom II processors are fully modern when it comes to power consumption. Some of the available chipsets from AMD and Nvidia (AMD's 780G, 790GX, 790FX, and Nvidia's nForce 750i, 780, i790i SLI) require less power than fully-featured Intel chipsets--usually because the memory controller is part of the processor, benefitting system idle power. Peak power doesn’t differ much from Intel’s offerings, though.
We were able to overclock several AM2+-based Phenom II X4 processors to almost 4 GHz, but all processors we got running at 3.8 GHz or slightly above would switch off the Cool’n’Quiet feature. This function reduces the processor speed and voltage when the CPU is idle, so it runs cooler and requires less power. This was an issue during our efficiency testing, as it would prevent the 3.8 GHz results to be compareble to the slower settings, which worked fine with Cool’n’Quiet. According to AMD, this is expected behavior resulting from manually keying in higher multiplier settings.
Related Stories :
- Optimizing Your Phenom II Overclock For Efficiency
- We Overclock Phenom II to 4.9GHz
- AMD Phenom II X6 1090T 'Black Ops' Overclocking
- AMD Phenom II X4 955 Overclocked to 7.1 GHz
- Phenom II On Ice: AM3 Overclocked With LN2
- Overclocking: Core i7 Vs. Phenom II
- Report: AMD Stops Shipping Phenom II and Athlon II CPUs
- AMD Phenom II X6 1100T Review: The New Six-Core Flagship
- Six New Phenom II And Athlon II CPUs From AMD
- Six-Core Analysis: AMD’s Phenom II X6 Gets Scaled Down
Great article! As always, Tom's showing another point of view for handling your hardware. And, yeah, Fusion works Bigtime! Better performance guaranteed.
Good article, I have always been curious about how effective certain clock increases would actually be; especially for locked AMD cpus as you have to retard the ram frequency to get the core clock up higher which may result in a bottleneck.
Useful article.
About the higher-than-spec voltage applied - however, it is not recommand to set higher that safety limit (recommanded by AMD) voltage AND CnQ enabled together - the CPU could become much less overclockable after a short period, due to damage by switching voltage up and down from unsafe voltage.
Useful article for amd users. We are waiting like this article for core i7 cpus too.
Well I'm already running my Phenom II 940 at 3.6, but I'm doing this with a mix of lower multiplier than 18 and slightly higher HTT clock, I'm running at 17.5x206=3605, ofcourse @ 1.4v.. I think it's a good idea to try the same overclocking speed but with the higher HTT clock, as this will increase the performance a little ( RAM will be overclocked too ).. it will be harder I know but it may worth the try...
ehh "But how far should you go? Efficiency has become almost equally important to performance," efficiency is more like the opposite of performance with overclockers really!
It's pointles to even consider efficiency as an overclocker! It's a bit like trying to tune a H2 for economy instead of torque or high rev horsepower .... you shouldn't have picked a H2 in the first place if efficiency is a concern.
Power saving features for when systems aren't doing anything are welcome, but anything else is imo irrelevant.
Indeed a Nice article after a Much time on Tomshardware, Straight and Up to the point in describing about the benefits of Overclocking..
Indeed a nice article. What i don't really "get" is why a Jetway mainboard was used? I can't even find a retailer in europe that has it on sale...
Hey Chris, thanks for getting the site's metadata updated. The charts became visible while I was reading this article.
Neiroatopelcc has a point, but Fusion should address that. Striving for performance does not mean striving for waste, it means ignoring it. Well, I don't think anyone would argue that ignorance is a good thing. People will be able to OC to the teeth when they need it, but still be efficient when they don't.
Great Overclocking article, but how about an underclocking article for the HTPC crowd? I'm kinda curious how much power different Phenom IIs use between 800 mhz & 2 ghz.
i still cant understand why does the i7 965 is 4x expensive than 940 ?
i still cant understand why does the i7 965 is 4x expensive than 940 ?
Because bragging rights are important to people with small genitalia, and they don't mind paying for that privilege.
Because bragging rights are important to people with small genitalia, and they don't mind paying for that privilege.
Not everyone likes to oc? although i don't get why you would go 965 over 920 unless that kind of money meant little difference to you.
what is fun about all this coments is that despite all things you say
im from argentina and this OC does not exist here jajaja
and in addition we have the devaluation of our money and it cost to us almost 4 times what costs you anything
example here a core 2 duo e8400 costs 800 pesos ... that is 220 dolars + -
and i presume that even that in where you live isnt the real cost... instead much lower
great page toms hardware by the way... the only thing is that everything is so expensive that i can only see the things but dont have it jajaja
yeah, ariel is right.. im from Argentina too.. as a computer technician i've seen a lot of monsters (super mega cooled I7's super mega overclocked Phenom's) but is not normal. i was thinkin on buying a system like this one (i cant afford a 1100 Watts PSU so i will go for something like 600 to 750W) and with that money me and my girlfriend live 3 months(including taxes). jejeje (no display included in the prize 'coz i already have a monitor).. I can't find anything that sounds similar to "Jetway" here.. so maybe i'll go for a MSI mother.. But i still have doubts as for the cooling.. What cooling solution was used in this article? stock cooler? the on ei see in the picture looks like a zalman or something like that.. can anyone answer that for me?..
Thanks in advance
Tom
I agree, this seems to be an usefull article. But as was said in the above, could it be possible to see an article where that "sweet point" 3.6 Ghz would be achieved using different HTT clock? Is it really worth of it? How it affects the power consumption? Maybe a very little, but it would be nice to see!
You all ready have proven that 3.6 GHz is the sweet point with normal HTT clocks, can the situation be different with different HTT settings? Or is it too much relative to the individual CPU you hapens to have?
All is all this was interesting article to read! Keep it up!
Very nice article
I was considering buying something a little more fancy than my OCZ Vanquisher so that i could go above 1.4v, but apparently there's no point, so thank you for saving me ~$100CDN.
There are still some unresolved questions here. Why a Jetway mobo with a 790GX chipset? Something with a 790FX would have made more sense. Why would you leave CNQ on during overclocking? The first thing every OC guide will tell you is to TURN CNQ OFF. Also, how much does power consumption/temperature increase as NB frequency goes up? i.e. if you increase the reference clock, rather than the multi, the NB freq. goes up. How does that impact stability/power consumption/temperature?
Still some mysteries here, but a nice article nonetheless.
To Chris or someone,
I dont know if the other users are experiencing this but every few pages I click through on this site, especially during the articles, I get a message from my antivirus alerting me of a virus from a file when im loading a new page. I click "Deny" each time and all seems well.
Virus: HEUR:Trojan.Script.Iframer
File: http://ad.trafficmp.com/a/js?plid=10637
Im using Firefox, Windows 7 build 7000, and Kaspersky for AV
Coop--let me report this and see what happens. The malware issue we saw before was solved. I sincerely hope this isn't something new. Thanks for the heads-up!