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
More Cores - The Ticket to Power Efficiency?
When Intel started on its quest for greater power efficiency we heard much about how the ticket would be more cores and multi-threaded applications. Instead of focusing on increasing clock speed Intel turned to the world and admitted that its gigahertz race was foolish, and that the next decade of performance improvements would come from increasing the number of cores per processor, not clock speed.
Back in 2005 Intel displayed the following chart, plotting a new curve for performance made possible mostly by the move to multi-core processors:
But at the same time, just as Intel had learned from the Pentium 4 family, an endless pursuit of performance (whether in the form of higher clock speed or more cores) will simply run us into another power wall. So as we were hearing about the performance improvements the multi-core era would bring us, we were also being told that Intel would not only improve the performance vector, but performance-per-watt as well. In fact, Apple cited Intel's focus on performance-per-watt as the driving factor in its adoption of Intel CPUs:
The introduction of Intel's Core microarchitecture proved one very important point: individual core improvements, as well as simply adding more cores, will both be necessary to drive better performance per watt in future microprocessors.
Looking at Intel's own numbers, the move from one to two cores improved performance per watt on the mobile side by around 50% while the move from NetBurst to Core on the desktop side increased performance per watt by a magnitude of 5x.
But is Kentsfield nothing more than a cleverly masked return to an older Intel? An Intel that used its manufacturing abilities to out-market AMD but left us with much higher power consumption than we wanted (and needed) to have? With Kentsfield we have two Conroes on a single chip, with no tweaks to the cores and very inefficient power management between the two die. Is this really no different than when Intel simply pushed out CPUs with higher clock frequencies, without addressing efficiency, to really turn up the heat on AMD?
Intel has said that it is committed to improving performance and performance per watt, but it was time to test that commitment with Kentsfield.
To put Intel's marketing and IDF presentations to the test we took six of our multithreaded benchmarks and ran them on a handful of configurations. Instead of just measuring performance, we also looked at average power usage during the benchmark and obviously, performance per watt. While all six benchmarks benefit from dual core CPUs, only four of them show a gain when using a quad core CPU, which should be useful in illustrating a very important correlation between number of threads and performance per watt.
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JarredWalton - Thursday, November 2, 2006 - link
I am quite sure that 4x4 is for 1207 and not AM2. Sorry. I am also quite sure that 1207 will get quad core support, so long-term a 4x4 (dual dual core) can become... 4x8? (dual quad core). Anyway, in that sense it's just like Core 2 Duo and Quad.The questions I don't have answers to: will the 4x4 begin with a K8L chip, or just a tweaked K8? Will K8L be more competitive with Core 2? When will it finally come out? How much will it cost? Actually, I can sort of guess on the last point that 4x4 will cost a lot more than a Core 2 Quad config as you will need a more expensive mobo, RAM, and two CPU packages.
I *think* Anand plans to have an article delving into 4x4 and AMD's plans more in the future. Maybe he's still gathering data from AMD? (Sort of like squeezing water from a dry spongue at times, unfortunately....)
johnsonx - Thursday, November 2, 2006 - link
I don't think you're right on that one; 4x4 CPU's will use the same RAM as AM2 CPU's do. The "more expensive RAM" requirement is only for Opterons, which of course use registered ECC memory. In fact, if your chosen mainboard has memory banks for both CPU's, then you could even save a little since 4 smaller DIMMs tends to cost a little less right now than 2 bigger DIMMs.
JarredWalton - Thursday, November 2, 2006 - link
Except that like socket 940 vs. 939, I expect all 1207 boards to require registered DIMMs. I don't know of any dual socket board that doesn't.Griswold - Thursday, November 2, 2006 - link
The whole "catch" of 4x4 was that there are no ECC/Registered DIMMS required - at least that was the synopsis all the time. It should have very little to do with the socket itself, rather a matter of IMC, no?Anand Lal Shimpi - Thursday, November 2, 2006 - link
You're correct, 4x4 will use Socket-1207 CPUs but without Registered memory.Take care,
Anand
JarredWalton - Thursday, November 2, 2006 - link
I stand corrected, though I have to say I'm still not at all interested in getting a dual socket motherboard. LOL I guess 1207 CPUs will have to support both registered and unbuffered DIMMs? I can't imagine AMD trying to get people to make sure they get the right type of CPU for the RAM they're using.Second thought: could they have mobos and CPUs that will support both registered and unbuffered DIMMs? I think they have the same keying, so it's possible, right?
smilingcrow - Thursday, November 2, 2006 - link
Two dual-core 90nm 120W CPUs = No thank you.Two quad-core 65nm xW CPUs = interesting!
Jedi2155 - Thursday, November 2, 2006 - link
I'm personally a extremely heavy multi-tasker and I can't wait for quad to a hit a more managable price range. At the moment, they're just beyond my reach for a CPU alone. Once it hits around 300-500 then I would definitely buy one, but these right now are still for the rich and video encoders.AlabamaMan - Thursday, November 2, 2006 - link
I am still amazed by the fact that a $300 E6600 consistantly beats the $700 FX62Aikouka - Thursday, November 2, 2006 - link
That fact, my friend, is why I'm purchasing an E6600 in this upcoming week :). Simply the best performance without overclocking for the buck.