Intel's Core 2 Extreme QX6700: The Multi-core Era Begins
by Anand Lal Shimpi on November 2, 2006 2:14 AM EST- Posted in
- CPUs
Performance per Watt Comparison
3dsmax 7
3dsmax, like many 3D renderers, absolutely loves more cores and here we see Kentsfield maintain a tremendous performance advantage over Conroe. The scores reported are the SPECapc 3dsmax rendering composite in points, higher numbers being better, but the most interesting values are the performance per watt numbers.
Note: we are looking at system power draw rather than trying to isolate just the CPU. In that sense, we are comparing potential of running quad core configurations - i.e. in render farms and the like - instead of more dual core systems. Were we to get just the CPU power usage numbers, we would expect the usage of two identical cores in a single package to basically double power draw.
| CPU | Performance |
Average Power Consumption | Performance per Watt |
| Intel Core 2 Extreme X6800 (2.93GHz) | 4.11 pts | 192.5W | 0.0214 pts/W |
| Intel Core 2 Extreme QX6700 (2.66GHz) | 6.59 pts | 230.5W | 0.0286 pts/W |
| Intel Core 2 Duo E6700 (2.66GHz) | 3.77 pts | 189.2W | 0.0199 pts/W |
| Intel Core 2 Quad Q6600 (2.40GHz) | 5.96 pts | 225.9W | 0.0264 pts/W |
| Intel Core 2 Duo E6600 (2.40GHz) | 3.39 pts | 184.4W | 0.0184 pts/W |
| Intel Core 2 Duo E6300 (1.86GHz) | 2.68 pts | 176.1W | 0.0152 pts/W |
| Intel Core 2 Single Core (2.40GHz) | 1.85 pts | 174.1W | 0.0106 pts/W |
With higher performance and higher power consumption, the two manage to balance out and result in better performance per watt out of the two Kentsfield based parts than any of the dual core CPUs. While Kentsfield does require more power than Conroe, you get an even larger increase in performance thus resulting in a more efficient overall CPU.
Let's see if this is the start of a trend...
Cinebench 9.5
The Cinebench 9.5 test is also a multithreaded 3D rendering benchmark that will take advantage of as many cores as are present in the system. For each core, Cinebench spawns an additional renderer to help speed up the rendering of a static scene. Performance goes up by over 60% when moving from two to four cores, but once again it's the performance per watt that is particularly interesting:
| CPU | Performance |
Average Power Consumption | Performance per Watt |
| Intel Core 2 Extreme X6800 (2.93GHz) | 892 pts | 189W | 4.719 pts/W |
| Intel Core 2 Extreme QX6700 (2.66GHz) | 1337 pts | 225.1W | 5.939 pts/W |
| Intel Core 2 Duo E6700 (2.66GHz) | 816 pts | 186.1W | 4.384 pts/W |
| Intel Core 2 Quad Q6600 (2.40GHz) | 1216 pts | 219.8W | 5.532 pts/W |
| Intel Core 2 Duo E6600 (2.40GHz) | 751 pts | 181.8W | 3.973 pts/W |
| Intel Core 2 Duo E6300 (1.86GHz) | 582 pts | 175.4W | 3.127 pts/W |
| Intel Core 2 Single Core (2.40GHz) | 402 pts | 172.2W | 2.334 pts/W |
None of the dual core CPUs can come close to touching the power efficiency of the quad core Kentsfield based offerings.
DivX 6.1
Media encoding applications were the first to get a performance boost from dual core CPUs, but the impact is not nearly as great when we move to quad core processors. There's a gain of around 38%, which is by no means bad, just simply not as great as what we saw in the previous 3D rendering tests. The end result is that performance per watt is a lot closer between the most efficient dual core CPUs and the new quad core offerings:
| CPU | Performance |
Average Power Consumption | Performance per Watt |
| Intel Core 2 Extreme X6800 (2.93GHz) | 19.4 fps | 189.2W | 0.1027 fps/W |
| Intel Core 2 Extreme QX6700 (2.66GHz) | 24.8 fps | 223.7W | 0.1108 fps/W |
| Intel Core 2 Duo E6700 (2.66GHz) | 18.0 fps | 185.7W | 0.0968 fps/W |
| Intel Core 2 Quad Q6600 (2.40GHz) | 24.0 fps | 220.0W | 0.1089 fps/W |
| Intel Core 2 Duo E6600 (2.40GHz) | 16.3 fps | 183.0W | 0.0864 fps/W |
| Intel Core 2 Duo E6300 (1.86GHz) | 13.8 fps | 176.9W | 0.0745 fps/W |
| Intel Core 2 Single Core (2.40GHz) | 11.2 fps | 170.7W | 0.0658 fps/W |
If we look at performance per watt per transistor, Kentsfield is really not doing well here at all, despite an increase in performance and a continued advantage in performance per watt.
Windows Media Encoder 9
We see a much stronger showing from Kentsfield in the WME9 test, indicating that the DivX test was not representative of all media encoding on quad core.
| CPU | Performance |
Average Power Consumption | Performance per Watt |
| Intel Core 2 Extreme X6800 (2.93GHz) | 61.5 fps | 189.1W | 0.3252 fps/W |
| Intel Core 2 Extreme QX6700 (2.66GHz) | 86.4 fps | 223.2W | 0.3870 fps/W |
| Intel Core 2 Duo E6700 (2.66GHz) | 55.8 fps | 184.5W | 0.3025 fps/W |
| Intel Core 2 Quad Q6600 (2.40GHz) | 78.9 fps | 218.6W | 0.3608 fps/W |
| Intel Core 2 Duo E6600 (2.40GHz) | 50.4 fps | 181.8W | 0.2665 fps/W |
| Intel Core 2 Duo E6300 (1.86GHz) | 39.4 fps | 176.9W | 0.2137 fps/W |
| Intel Core 2 Single Core (2.40GHz) | 31.3 fps | 171.7W | 0.1822 fps/W |
Quicktime (H.264)
Interestingly enough, our Quicktime H.264 test didn't show any performance improvement going from two to four cores, indicating that the encoding process is optimized for two threads. Quicktime thus becomes the posterchild for what's necessary for the multicore revolution to truly bring about greater power efficiency: better threading within applications.
| CPU | Performance |
Average Power Consumption | Performance per Watt |
| Intel Core 2 Extreme X6800 (2.93GHz) | 30.0 fps | 191.2W | 0.1569 fps/W |
| Intel Core 2 Extreme QX6700 (2.66GHz) | 27.5 fps | 210.0W | 0.1309 fps/W |
| Intel Core 2 Duo E6700 (2.66GHz) | 27.5 fps | 188.1W | 0.1461 fps/W |
| Intel Core 2 Quad Q6600 (2.40GHz) | 25.2 fps | 207.0W | 0.1216 fps/W |
| Intel Core 2 Duo E6600 (2.40GHz) | 26.5 fps | 185.1W | 0.1430 fps/W |
| Intel Core 2 Duo E6300 (1.86GHz) | 19.8 fps | 177.7W | 0.1113 fps/W |
| Intel Core 2 Single Core (2.40GHz) | 16.2 fps | 170.6W | 0.0951 fps/W |
Here the dual core offerings are clearly superior when it comes to performance per watt simply because the Kentsfield CPUs aren't able to outperform them, all while using more power. The efficiency wouldn't be a problem if Kentsfield was able to power down unused cores independently of one another.
iTunes MP3
Our final test is yet another benchmark that only spawns two encoding threads, and we get another example of how power efficiency falls off if the software is not threaded enough to match the CPU's resources.
| CPU | Performance |
Average Power Consumption | Performance per Watt |
| Intel Core 2 Extreme X6800 (2.93GHz) | 11.7 MB/s | 193.4W | 0.0605 MBps/W |
| Intel Core 2 Extreme QX6700 (2.66GHz) | 10.9 MB/s | 213.1W | 0.0509 MBps/W |
| Intel Core 2 Duo E6700 (2.66GHz) | 10.5 MB/s | 188.3W | 0.0557 MBps/W |
| Intel Core 2 Quad Q6600 (2.40GHz) | 9.8 MB/s | 206.8W | 0.0474 MBps/W |
| Intel Core 2 Duo E6600 (2.40GHz) | 9.8 MB/s | 185.4W | 0.0529 MBps/W |
| Intel Core 2 Duo E6300 (1.86GHz) | 7.6 MB/s | 177.0W | 0.0429 MBps/W |
| Intel Core 2 Single Core (2.40GHz) | 6.1 MB/s | 168.4W | 0.0361 MBps/W |
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JJWV - Tuesday, January 23, 2007 - link
I bought a QX6700 for crunching at numbers. The reasoning was simple twice the power, only one MB, disk, PSU, case...The result is disappointing, the maximum throughput I get is not twice an E6700, it is just a little more than one an half : 1,6 to be precise. The bottleneck is definitely the memory. The Northbridge cannot communicate fast enough with the memory. 5I came to this conclusion by varying multiplier, FSB...) Perhaps it would be worthwhile with the faster memory available 9200, but I am afraid even that kind of memory is to slow. The Quadcore is where Intel went over the edge with their memory architecture.
Kougar - Tuesday, November 14, 2006 - link
Any ideas on the Apache benchmarks I am seeing with a QX6700? They are appalling at best, with a QX6700 performing on par to a E6400!! A little of the same problem seems to have shown up in Office Productivity benchmarks. Any thoughts on this?in1405 - Monday, November 6, 2006 - link
<<<No article looking at a new processor release would be complete without benchmarks. However, let us preface the benchmark section by stating that the benchmarks don't tell the whole story. There are numerous benchmarks and tasks that you can run that will actually show quad core processors in a better light. A lot of people will never use the applications related to these benchmarks, so in one sense we could say that most people should already know whether or not they need quad core processing.>>>Some interesting comments here on the relevance of Benchmarks .. This looks interesting as this point of view never came up while the AMD CPUs were being glorified a few months back in this same site!! Wonder where the sudden wisdom comes from.
LTC8K6 - Sunday, November 5, 2006 - link
Why not compare dual to quad by trying to run things in the background while you do something in the foreground? Encode something and play Oblivion, for example. Would we finally be able to do anything like that with quad cores? Are we able to get good framerates in such a situation yet?Webgod - Thursday, November 2, 2006 - link
How about running http://www.driverheaven.net/photoshop/">DriverHeaven.Net's Photoshop CS2 benchmark? I think one of your standard magazine benchmarks has Photoshop 7, but the DH benchmark is newer and it's somewhat popular. Anybody can download a demo from Adobe, and run the benchmark on their own PC.coldpower27 - Thursday, November 2, 2006 - link
Check Intel's current price list here:http://www.intel.com/intel/finance/pricelist/proce...">http://www.intel.com/intel/finance/pricelist/proce...
JarredWalton - Thursday, November 2, 2006 - link
Actually just the 820 and 914 - 805 didn't get a price cut this month. But I fixed the other two, thanks. :)coldpower27 - Thursday, November 2, 2006 - link
oh yeah my bad, didn't mean to add the 805 in there.by the way, check your email please.
OddTSi - Thursday, November 2, 2006 - link
On page 7 you say "Apple's OS X and its applications have also been well threaded for quite some time..." yet the only two Apple apps in the test (Quicktime and iTunes) didn't scale AT ALL from 2 to 4 cores. I'm not trying to bash Apple here I'm just trying to point out that the facts don't seem to support your assertion. If Apple's media rendering apps - which are some of the easiest to multithread - don't scale well I doubt that the rest of their apps do.mino - Thursday, November 2, 2006 - link
Maybe cause there is a catch?You see, WinXP is not very OSX like, not to mention its apps ;)