Intel's Core 2 Extreme & Core 2 Duo: The Empire Strikes Back
by Anand Lal Shimpi on July 14, 2006 12:00 AM EST- Posted in
- CPUs
FSB Bottlenecks: Is 1333MHz Necessary?
Although all desktop Core 2 processors currently feature a 1066MHz FSB, Intel's first Woodcrest processors (the server version of Conroe) offer 1333MHz FSB support. Intel doesn't currently have a desktop chipset with support for the 1333MHz FSB, but the question we wanted answered was whether or not the faster FSB made a difference.
We took our unlocked Core 2 Extreme X6800 and ran it at 2.66GHz using two different settings: 266MHz x 10 and 333MHz x 8; the former corresponds to a 1066MHz FSB and is the same setting that the E6700 runs at, while the latter uses a 1333MHz FSB. The 1333MHz setting used a slightly faster memory bus (DDR2-811 vs. DDR2-800) but given that the processor is not memory bandwidth limited even at DDR2-667 the difference between memory speeds is negligible.
With Intel pulling in the embargo date of all Core 2 benchmarks we had to cut our investigation a bit short, so we're not able to bring you the full suite of benchmarks here to investigate the impact of FSB frequency. That being said, we chose those that would be most representative of the rest.
Why does this 1333MHz vs. 1066MHz debate even matter? For starters, Core 2 Extreme owners will have the option of choosing since they can always just drop their multiplier and run at a higher FSB without overclocking their CPUs (if they so desire). There's also rumor that Apple's first Core 2 based desktops may end up using Woodcrest and not Conroe, which would mean that the 1333MHz FSB would see the light of day on some desktops sooner rather than later.
The final reason this comparison matters is because in reality, Intel's Core architecture is more data hungry than any previous Intel desktop architecture and thus should, in theory, be dependent on a nice and fast FSB. At the same time, thanks to a well engineered shared L2 cache, FSB traffic has been reduced on Core 2 processors. So which wins the battle: the data hungry 4-issue core or the efficient shared L2 cache? Let's find out.
On average at 2.66GHz, the 1333MHz FSB increases performance by 2.4%, but some applications can see an even larger increase in performance. Under DivX, the performance boost was almost as high as going from a 2MB L2 to a 4MB L2. Also remember that as clock speed goes up, the dependence on a faster FSB will also go up.
Thanks to the shared L2 cache, core to core traffic is no longer benefitted by a faster FSB so the improvements we're seeing here are simply due to how data hungry the new architecture is. With its wider front end and more aggressive pre-fetchers, it's no surprise that the Core 2 processors benefit from the 1333MHz FSB. The benefit will increase even more as the first quad core desktop CPUs are introduced. The only question that remains is how long before we see CPUs and motherboards with official 1333MHz FSB support?
If Apple does indeed use a 1333MHz Woodcrest for its new line of Intel based Macs, running Windows it may be the first time that an Apple system will be faster out of the box than an equivalently configured, non-overclocked PC. There's an interesting marketing angle.
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ianwhthse - Friday, July 14, 2006 - link
Hmm... some more investigating.Firefox leaves space for the images, so I right-clicked and sure enough, I've got a link. "View Image" to look at a single .png, and I get a white blank screen (properties of this particular image says 446px by 654px, 0.04kb in size).
JarredWalton - Friday, July 14, 2006 - link
I'm using Firefox without trouble. Possibly some firewall setting is getting in the way? We had a few brief issues earlier tonight, but that only lasted a few minutes (and we're not sure what happened). If IE and FF both lack images, it sounds like something outside of browser. One note is that I think our image server (images.anandtech.com) blocks access to images if you don't allow the referring URL to be passed along. Meaning, if you were to get the URL of an image and paste that directly into a browser, the image would show up as a 1x1 blank file. Not sure if that affects the graphs as well or not.ianwhthse - Friday, July 14, 2006 - link
It was the referer info being blocked that was doing it, kinda annoying. Thanks a million.JarredWalton - Friday, July 14, 2006 - link
Norton is the devil, I swear. They were great when Peter Norton was actually involved, but now it's just a name, and every release gets worse IMO. Norton Internet Security 2002 (2001?) was good; 2003 became a bit worse. 2005 was garbage and I never tried it again. I don't even run software firewall/anti-virus anymore. I've got a hardware firewall, surf with Firefox, password protect my PCs, and don't open stupid email messages. That only works because I'm the only one on the network/PCs, of course. :)ianwhthse - Friday, July 14, 2006 - link
Yeah, I run an old corporate edition from maybe 2001-2002 because I can't stand the fat of the newer releases. And it's just worked well for me otherwise, I've got a newer edition sitting around in some pile of disks in some closet, but I tried it, hated it, went back.I've got a hardware firewall, software firewall, AV, surf w/Firefox, anti-Spyware, AND try not to do anything stupid -- I got'cha beat =P
ianwhthse - Friday, July 14, 2006 - link
Hmm...I see all the ads on the page (newegg, zipzoomfly, thermaltake, crucial, etc.) that seem to be flash. I also see the images for the header of the page (the Anandtech logo at the top of the page), but it's just the images in the review that are invisible.
Hmm... I told the firewall (Norton) to lower my protection, and nothing [either browser]. I'll give it a stab disabled.
*sign* Okay, charts worked w/o Norton running... (even on minimum protection, they wouldn't come up). I guess I'm off to delve into what setting is going to be doing that.
Gary Key - Friday, July 14, 2006 - link
If you are using Opera 9 or 8, did you turn on "refferer" logging under tools - quick preferences or the advanced - network option?xFlankerx - Friday, July 14, 2006 - link
Excellent article, by far the most detailed released yet. Yea, the E6400 was a rather important part since it's supposed to be equal to AMD's flagship FX-62, but its easy enough to figure out how it would perform from the other processors' performance.As for Conroe availability; 25% of Intel's total output should be more than enough. 20% of Intel's manufacturing capacity equals 100% of AMD's. If there is no shortage of AMD processors, 25% of Intel's total output should be more than enough to supply the market with enough processors?
DigiTimes also reported that Intel will be charging everyone roughly the same price for the processors. Dell might not get the processors for half-off after all.
That said, these processors are amazing. By far the greatest thing since the Athlon 64 almost 5 years ago. Fun stuff.
mikaela - Tuesday, March 16, 2010 - link
yes, well-written. i also love the images provided here. thanks i can use the info here to write my essay college essay requirementsSuraj - Friday, October 20, 2006 - link
Great article. How did they overclock the e6600? Did they use the same parts listed in "The test" ?