The Core 2 Quad Q8400: Intel's $183 Phenom II 940 Competitor
by Anand Lal Shimpi on May 7, 2009 12:00 AM EST- Posted in
- CPUs
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.
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eXistenZ - Thursday, May 7, 2009 - link
Obviously, AMD is no good in Far Cry 2 game. K8, K10, K10.5, al these architectures were always slower than intel's competitors. And it is really crappy game, so i don't see any reason why are you testing right on this one. I think, more fair testing is with Crysis or CPU-eaters = RTS...Goty - Thursday, May 7, 2009 - link
Anand seems to be buying into all the FUD about AMD lately. Sure, AMD's not doing so hot right now, but they're not in much worse a position than they were in the middle of the P4 era (probably about the same position, all told).Anand Lal Shimpi - Friday, May 8, 2009 - link
I'm not sure I would call it FUD. AMD lost $2.36B before taxes in the last four quarters combined. Their chief competitor made $6.13B. Now Intel has always made more than AMD, but the issue now is that AMD is losing a considerable amount every quarter. That can only continue for so long.What I'm more worried about is the impact this is having on the next-generation cores that AMD is developing. While engineering budgets are the last things to go, if you're losing a few hundred million a quarter everyone from marketing to engineering gets hurt.
Ignoring the problem isn't going to make it go away, I felt that it would be important to at least bring some of this stuff to the table so we can at least be thinking about it.
Take care,
Anand
microAmp - Thursday, May 7, 2009 - link
Actually, it's worse, they are running out of cash.ssj4Gogeta - Thursday, May 7, 2009 - link
"It's the beauty of Moore's Law: with fewer transistors crammed into a much smaller area, we're able to see the same performance."Shouldn't it be "MORE transistors crammed into a much smaller area"?
:)
hooflung - Thursday, May 7, 2009 - link
I am another that buys based on the ability of Virtualization via virt functionality. I got a P2 940 because I wanted the ability to have 4 cores to split up to VM's running Hyper-V, Xen and KVM. I just can't do that on new intel chips that fall in the price range right now.My C2D is still rocking a venerable 1ghz OC on a e4300 and P35 chipset. For me to install an OS to do development as the top level is just wasting wattages at my home.
snakeoil - Thursday, May 7, 2009 - link
''Phenom II Earns a Financially Troubled AMD Less per Chip than Core 2 Quad''well you are saying that amd make less money because phenom 2 has a little more area,but in your happy calculations you forgot that bad quad core dies are used to make tricores and soon dual cores phenoms.
harvesting.
what are you doing little annand
crimson117 - Thursday, May 7, 2009 - link
One wafer costs a fixed amount to make; let's say $200.Let's say AMD can get 10 CPUs made from each wafer, while intel can get 20 smaller CPUs from each wafer. They each sell their chips for $180.
AMD puts $200/10 = $20 worth of wafer into each $180 CPU.
Intel only has to put in $200/20 = $10 worth of wafer into each $180 CPU.
So assuming all other things are equal, Intel makes $5 more on each CPU sale than AMD.
crimson117 - Thursday, May 7, 2009 - link
*clicks Edit button*So assuming all other things are equal, Intel makes $10 more on each CPU sale than AMD.
mkruer - Thursday, May 7, 2009 - link
You are also forgetting that AMD and Intel use two different lithphogathy technologies to AMD uses submersion and Intel uses double pattering. The Submersion takes slightly longer then a single pattering, and yeild fewer defects. This meas that AMD should be able to preduce a high volume of chips per platter then Intel. Adding to the confusion, is that neiter intel nor AMD releases what there yeilds are and as such, too comepare based upon die size alone is folly. People can crunch the numbers anyway they want, but in the end it should be a, for more or less, wash.