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
Memory Latency: No Integrated Memory Controller Necessary
One thing we pointed out in our earlier preview coverage of Intel's Core 2 Extreme is that the new processors have extremely low latency memory access, despite relying on the same memory controller as the previous generation of Intel CPUs.
Without an on-die memory controller Intel's Core 2 processor must use the memory controller in its chipset, which currently means the 128-bit DDR2 memory controller in either Intel's 965 or 975X chipset. The confusing thing is that although the Core 2 processors use the same memory controller as the old NetBurst processors, memory latency has been improved tremendously:
Intel's Core 2 processors now offer even quicker memory access than AMD's Athlon 64 X2, without resorting to an on-die memory controller. While Intel will eventually add one, the fact of the matter is that it's simply not necessary for competitive memory performance today thanks to Intel's revamped architecture. Update:As many astute readers have pointed out, Core 2's prefetchers are able to work their magic with ScienceMark 2.0, which results in the significant memory latency advantage over AMD's Athlon 64 FX-62. This advantage will not always exist; where it doesn't, AMD will continue to have lower latency memory access and where it does, Intel can gain performance advantages similar to what ScienceMark 2.0 shows.
| CPU | Everest |
CPU-Z 1.35 (8192KB, 128-byte stride) | CPU-Z 1.35 (8192KB, 64-byte stride) |
| AMD Athlon 64 FX-62 (2.8GHz) | 45.9 ns | 43.2 ns | 19.3 ns |
| Intel Core 2 Extreme X6800 (2.93GHz) | 59.8 ns | 52.8 ns | 10.9 ns |
Because of the Core 2's intelligent prefetchers doing too good of a job with ScienceMark memory latency test, we wanted to also showcase situations where Core 2 would feature slower memory accesses than the AMD platform with its integrated memory controller. Everest's results are more in line with what we'd expect to see, with the FX-62 offering over 23% faster memory accesses than the X6800. CPU-Z's latency tool also reported somewhat similar findings, with an 18% performance advantage due to AMD's integrated memory controller. CPU-Z also provided us with numbers that showcase how well Core 2 can perform if its prefetchers are able to "guess" correctly; at lower strides the Core 2 Extreme manages faster memory access than the FX-62. The 128-byte stride numbers are indicative of what will happen if the pre-fetchers are not able to get the Core 2 the data it needs, when it needs it, while the 64-byte numbers show you what can happen when things go well.
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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" ?