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
Using a Quad Core System
Intel's first dual core processors, codenamed Smithfield, were actually the first 90nm Intel CPUs we actually recommended. The reason being that the real world performance improvement brought about by having two cores at your fingertips was simply too much to resist, especially if you were a heavy multitasker. A big reason for the improvement in real world performance came about because of inefficiencies in the way Windows XP's scheduler handled juggling multiple threads, especially on a single core CPU. The move to dual core got rid of many of those nasty Not Responding windows when Windows' scheduler would simply never properly allocate CPU cycles to a particular thread.
Inevitably the same thread juggling problems we saw with single core CPUs would eventually apply to dual core CPUs, just with more active threads. Intel once told us that we'd run into the same sort of scheduler/CPU cycle limitations at a bit over a dozen active threads on a dual core CPU, meaning at that point, it's time for four cores.
We performed a quick test to see if we could spot the real world difference in multitasking and system responsiveness between a dual core and a quad core CPU. We took our test bed and ran as many multithreaded benchmarks as we could feasibly start without completely bogging down the system; we ran our 3dsmax, Cinebench, DivX, WME and iTunes tests all at the same time, not to see how fast they'd run, but to see how responsive the rest of the system would be with a dual core CPU vs. a quad core CPU.
On both systems we had no problems launching Explorer windows or navigating the OS while all of those tasks executed, indicating that we were no where near that saturation point where the entire system becomes unresponsive; good news for dual core owners.
We could switch between all of the running applications without running into a window that wouldn't respond, with the exception of iTunes. Regardless of whether we had two or four cores at our disposal, iTunes would only respond when it felt like it. Although the encoding task was continuing, we couldn't interact with the application without waiting a handful of seconds for it to regain consciousness.
The primary difference between two and four cores in our very heavy multitasking scenario was in the work that got done. While the 3dsmax, DivX, WME and iTunes tests all managed to inch along during our test, with a dual core setup the Cinebench test wouldn't even start until after iTunes had completed. On the quad core setup, Cinebench ran alongside iTunes, albeit at a slow pace.
It's a faint difference but it does highlight an important point - even the heaviest of multitaskers aren't likely to see a huge difference in system responsiveness with four cores vs. two. It is in the performance of individual threads, especially when you have a lot that are contending for CPU time, that you'll see a much bigger difference between Kentsfield and Conroe.
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archcommus - Thursday, November 2, 2006 - link
Quote form the conclusion page:"We don't expect dual or quad core to be necessary for gaming anytime in the next 9 months..."
Really? That is surprising to hear. 9 months takes us to next July. I thought Alan Wake would definitely be released before then, and I thought that game REQUIRED two cores and would greatly benefit from four. Are you sure that statement isn't supposed to read "We don't expect QUAD CORE to be necessary for gaming anytime in the next 9 months..."?
JarredWalton - Thursday, November 2, 2006 - link
I thought Alan Wake was looking more like late 2007 (along with Unreal Tournament 2007 and some other games). We'll have an article looking into this area a bit more soon, but right now the games aren't out; they're in development, but the "when it's done" attitude often leads to launch dates that get pushed back.floffe - Thursday, November 2, 2006 - link
One game isn't gaming in general ;)johnsonx - Thursday, November 2, 2006 - link
AT Writers:The first chart on page 1 seems to have a typo. It states the Core 2 Quad has a die size of 162mm^2x2. But it shows the Core 2 die size as 143mm^2. If the Quad is just two Core2 dies, then why are they so much bigger?
The quoted die size of the Pentium D 900 at 162mm^2 suggests the source of the typo.
coldpower27 - Thursday, November 2, 2006 - link
As well if were going to be consistent and and call Core 2 Quad as 2x 143mm2 which is the right figure I might add not 2x 162mm2, then the Pentium D 900's should indeed be 2x81mm2 and not 162mm2 as it is stated right now on the chart.coldpower27 - Thursday, November 2, 2006 - link
Continued.. The reason being as the Pentium D is also 2 die on a single package just like Kentsfield as in this case you had 1 core on each die instead of a 2 core per die arragement.Sunrise089 - Thursday, November 2, 2006 - link
All I really needed to know from this article:1) Responsiveness isn't any better from CoreQuad
2) No mainstream software that I might use will take advantage of 4 cores in the near-future.
4) Quad-core does come at a large price increase (it isn't a free-lunch like the first dual-core chips from Intel were)
5) Quad-core doesn't overclock as well.
Decision - almost everyone who buys this at these prices is making a mistake, by the time the software catches up with this everyone will be ready to upgrade again.
eoniverse - Thursday, November 2, 2006 - link
From a gaming perspective definately. But if you render I like the performance increase. Price does suck. However when AMD 'replies' middle of 07 - the prices will adjust.And I'll be buying 'something'.
rowcroft - Thursday, November 2, 2006 - link
Do you think that with four cores, there are other bottlenecks limiting performance? I would think that moving to a striped disk array would be representative of a system that has a $999 processor.With four cores I would imagine there is some disk access contention happening. Especially since the iTunes test using write/reads pretty heavily doesn't it?
I'm no expert, just my thoughts.
EnzoM3 - Thursday, November 2, 2006 - link
Not a fan of one giant strip array. IMO, if disk contention is a problem, isolate the tasks that are contenting for disk access, then put the data on seperate physical drives. I put iTunes on one drive, page file on another, system files on main drive, videos and edits on another, and finally all iso's on one. Disk contention is never an issue even though rest of my system could use upgrades.