The Core 2 Quad Q8400: Intel's $183 Phenom II 940 Competitor

Name: The Core 2 Quad Q8400: Intel's $183 Phenom II 940 Competitor
Item: The Core 2 Quad Q8400: Intel's $183 Phenom II 940 Competitor
Author: Anand Lal Shimpi

by Anand Lal Shimpi on May 7, 2009 12:00 AM EST

Posted in
CPUs

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60 Comments

Overclocking with a 10% Increase in Core Voltage

While there's something nice about not having to do anything to overclock your CPU other than adjusting a single parameter, tweaking your core voltage has the potential to significantly increase your overclocking potential.

Let's start with the Phenom II X4 940. Using the stock AMD cooler and pushing a max 10% increase in core voltage we ended up with 3.6GHz and a 2.2GHz NB frequency at 1.475V:

I was able to get the chip up to 3.9GHz but not stable enough to complete all of my tests over a significant period of time. Still, a 20% overclock with a moderate increase in core voltage isn't bad at all.

The Core 2 Quad Q8400 saw a 15% increase in clock speed without touching the core voltage. Bumping the core voltage up to 1.45V bought us another 11% taking the chip up to 3.36GHz:

At 3.6GHz vs. 3.36GHz, AMD's clock speed advantage grows to ~7%. Not as big as the 12.7% clock speed advantage at stock frequencies but bigger than the 4% difference in our stock voltage OC attempt.

Processor	Adobe Photoshop CS4	x264 HD - 2nd pass	POV-Ray	Far Cry 2	Idle Power	Load Power
AMD Phenom II X4 940 @ 3.6GHz	20.3s	21.3 fps	2839	51.5 fps	120.8W	256W
Intel Core 2 Quad Q8400 @ 3.36GHz	18.0s	22.3 fps	2771	59.5 fps	139.9W	213W

At max overclock something interesting happens. Obviously the Q8400 holds on to the lead in Photoshop and Far Cry 2, but POV-Ray goes back to AMD. The x264 encode ends up being a mild victory by the Q8400. Far Cry 2 is bizzare as the Phenom II saw no performance improvement from 3.2GHz up to 3.6GHz, regardless of how many times I ran the test I could never get a higher frame rate out of the system - even with CnQ disabled.There must be some other bottleneck operating here, but it's not a GPU one since the Q8400 was able to scale all the way up to 59.5 fps with the same graphics card.

The situation seems to boil down to this - at max frequency the Phenom II will probably retain its performance lead in 3D rendering and ray-tracing applications, while the video encoding lead goes to Intel. Power consumption also favors the Q8400 significantly.

Overclocking at Stock Voltages Final Words

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enu73 - Monday, August 24, 2009 - link
Oh God so confusing, Please help me, i am planning a gaming PC, what should I choose Intel 9400 or AMD 940,,
Please please help me
ashr7870 - Wednesday, April 13, 2016 - link
I do hope you chose the X4-940~
realpower3288 - Thursday, July 16, 2009 - link
Hi,

I was trying to see the benefit of moving to quad core performace on my P35 chipset which is a budget build.. so i went and behold, got a Q8400 for just USD 150.. after some bargaining... threw my OC dual core to the store room..

when i first power up my PC, i was like hmmm it seems slower during loading boot up... loading of certain apps. Some apps seem faster.

So i decided to try doing everything at once...installing world in conflict.. stream youtube..chat and work. had 24 inch wide LCd... so multitask is not that painful. Not bad, I could never do this on a dual core, there was no lag in switching apps and its fast..

To cut the story short, it was slower in loading certain apps and games (modern FPS, strategy). So i decided to OC ... ho ho i easily reach 3.5 Mhz with my recycled artic cooler at 60C max load. I have not even gone to max coverclock speed yet.

My view on this chip, in its default settings it is just a low speed quad core.. but when you overclock this chip it seems to be nuclear powered... (loaded 2 games and switched side by side to play)....
Wait is this another chip in disguise???
v12v12 - Saturday, May 16, 2009 - link
I don't really care about a few pittance dollars vs Intel. I'm not an intel-zealot. But I can clearly see who actually has a CONSISTENT performance road map Vs a couple 1-hit-wonders and a crappy album with filler chips.

Intel has proven their roadmap is viable; if all you AMD fanboys want to get socket-locked into a highly ambiguous hardware platform. then be my guest. I'll stick with Intel and wait for the price drop (they have a pattern, proving this) and know for certain that my current hardware will be on an upgradeable path to i7-Core, when their price drops... THEN what answer will AMD provide? It can barely "compete" (see 1-2 chips barely making PAR is NOT "competitive") with the antiquated Core2Duo... Nehalem is at min 20-30% faster and growing with every *tick* & *tock* release.

Unfortunately I understand the AMD'ers passion and pull for them; I AM pulling for them, as it's better for prices when competition is high. I'm on my old XP-A right now, but I refuse to drink the coolaid. AMD did great to catch up to C2D, but a little late don't you think? Go AMD... but please shop with sense.

Your AMD box that "competes" now, will soon be a hard to sell item, once it falls even further behind, when Intel decides at a whim to drop prices. Competing on price is a very fickle and unreliable method of securing sales. Compete with superior products and they will sell themselves.
Hatisherrif - Sunday, May 10, 2009 - link
Well, if people were smarter then we'd not only have AMD to talk about, but it would be a question if Intel could stay on it's legs. As AnandTech recently mentioned in their Crossfire Phenom II review, the gaming performance on AMD chips is much smoother and fluid. But when "gamers" see a benchmark with Intel above 120 and AMD at 90 they want to go Intel for sure. That is why everyone should read from trusted sources that give personal opinion and experience in games. It is my personal experience also. I have 9800GT with 4GB RAM and Intel E4600, while my friend has 2GB, 9600GT and AMD Athlon 5000+. Every single game lags due to low fps on my rig, while on his, with twice less RAM, goes as fluid as hell. It doesn't even lag on explosions or anything. Besides that, his system is much more stable and fast. But noooooooooooo, ME'Z GONNA BUYZ INTELZ BEKAZ INTELZ MONOPOLZ IZ GUUUD. AND INTELZ HAZ HIGHER FPS!
Lolimaster - Saturday, May 9, 2009 - link
You want to see a true review with real numbers results?

How about this?
Q9650 vs PII 940 (Both at 3Ghz)

video compressión/edition
audio compresión/edition
3d render
image edition
etc

http://foro.noticias3d.com/vbulletin/showthread.ph...">http://foro.noticias3d.com/vbulletin/showthread.ph...

The results?
On average the Q9650 is 4-5% faster than the 940. Obviously you not find this in "inteltech, your source for hardware-bias analisys and news".

Now the 940 is way cheaper than the Q9550, that's a deal. Intel need to drop prices, but they don't want to, you think a slowy Q8400 has a good price? You're part of the problem.
mhahnheuser - Friday, May 8, 2009 - link
I have used alternative cpu's for years because although not always up to speed they competed well feature for feature and were simply more price/performance competitive. AMD has spent most of its life performing lower in BM's to Intel. Why this is the biggest news since bread came sliced to the Intel community all of a sudden is a mystery to me. (It's not really, they are hanging on by their fingernails, and clinging to any fact no matter how pathetic).

Now that there is something that won't run on these cheap flogger Intel cpu's, that won their fine reputations on the refined and outrageously expensive cousins, and.......

suddenly it's "Houston we have a problem," and we(Anandtech) defend the indefensible, with a bucket load of excuses, or was it that we now have to defend the fact that we relentlessy flogged that technology to consumers without asking enough questions? Now, suddenly, virtulisation doesn't matter. Thank god it wasn't AMD who left it off.

This is a sad sad article as I think it is deeply misleading. Not only does the article clearly show that the P2 940 is superior in performance, offers the independant core technology found only in Intel's latest processors the i7 & the as yet phantom i5, and offers platform upgrade path to DDR3 memory and has virtulisation included and that, somehow, is concluded that the 8400 is a viable alternative. Get real Anantech! time wake up in the real world.

The real news in this article was that, to my vast ammusement I might add, the fabeled and much vaunted Q6600 starting to fall behind the X2 in some of the benchmarks. Is this a result of the forward thinking of AMD to go independant core? I wonder.
skasucks478 - Monday, June 1, 2009 - link
DDR2 v DDR3 is no real deal breaker for building a system of now. DDR3 is new (and more expensive for the little performance difference) and very far from being what DDR2 is now to DDR. The joy of new RAM type is that it will be at least 6mo until DDR3 is the "OH HELL YEAH!" RAM.

Oh, don't look now, but a lot of 775 boards now offer DDR3!
FalcomPSX - Friday, May 8, 2009 - link
Maybe i just got lucky, but my phenom II 940 overclocks extremely well. On stock cooling, without bumping the voltage one bit i'm able to hit 3.5ghz, 100% stable while gaming, or stressing the cpu. a bump of 0.05v to 1.40 was all i needed to get 3.6ghz stable, but at that point temps started to get too high for the stock cooler between the increased speed and voltage bump. It ran fine for hours, but i just prefer lower cpu temps(at this point i was seeing 60 C at 100% load) I have no doubt in my mind i could easily get to ~3.8ghz with a aftermarket cooler and a bit more voltage. Unlocked multipliers make it ridiculously easy to overclock these things, and once i hit a wall, i can tune individual cores. Intel can't compete with these features unless you go to their extreme edition $1000+ cpu's.
lef - Monday, May 11, 2009 - link
You are not lucky. Mine also overclocks to 3.4Ghz on stock voltage/cooling at 17x and these guys can only do 3.2ghz ... i haven't even tried 3.5 but since you are able to hit it i will try it