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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bob661 - Friday, July 14, 2006 - link
Sorry but the Netburst stuff is STILL garbage. Core 2 is head and shoulders better than anything they've made since the P3. Although, I thought the power consumption would be better.aznskickass - Friday, July 14, 2006 - link
Man, some AMD fanboys just can't take defeat with dignity.Really expensive? Top of the line, sure, but funny you fail to mention the E6300 and E6600, which both offer far better value than the equivalent priced A64.
Finally match (or even exceed by a few points)?
OK, here is where I suggest you get your eyes checked out, or go back to school and learn to read graphs. C2D *spanked* A64, not 'match it or exceed it by a little'.
I think you are just upset that AMDs days as performance crown are over. Tough life being a fanboy eh. You gotta take the ups with the downs son. ;)
epsilonparadox - Friday, July 14, 2006 - link
how is a $999 C2E hundreds of dollars more than a $999 FX-62? How is a 55% increase in performance "match (or even exceed by a few points)"? Perhap a slow reading of the article is need.Genx87 - Friday, July 14, 2006 - link
Intel has a hot chip on their hands here. Problem is, when will it have SLI available?And when will we finally see a review using an Nvidia chipset on the AMD side of this equation?
Bozo Galora - Friday, July 14, 2006 - link
newegg has started the conroe game by getting a $460 premium on extreme CD2http://www.newegg.com/Product/Product.asp?Item=N82...">http://www.newegg.com/Product/Product.asp?Item=N82...
Bozo Galora - Friday, July 14, 2006 - link
errr......thats a rape of $360, not $460 - my bad (duh)
bob661 - Friday, July 14, 2006 - link
It's not on the website anymore. I can't find any Conroe's up their at all. Non-existant. Also, and I know some of you read this but didn't AT say that the supply Conroe would be tight and would drive prices up until the end of the year? So why the bitching about higher prices? If Dell and others are buying up and making supply tight then prices go up. That's the way stuff is.Also, who has a Conroe other than the EE that we can buy today? Also, if these CPU's aren't available and today is the launch day then wouldn't this be considered a paper launch? And one more thing, where are the motherboards for this thing?
yacoub - Friday, July 14, 2006 - link
technically a paper launch means there were none available at all on launch date. my understsanding is that there were some of these available, they have just been bought up. a limited supply is still better than a true paper launch, imho, even if the end result is the same for most of us - no product available to buy.JarredWalton - Friday, July 14, 2006 - link
This is a paper launch, and there's a variety of political reasons for it. Among the reasons:1 -- AMD is cutting their processor prices in a couple weeks, right after Core 2 Duo was supposed to launch. Intel wanted to launch first.
2 -- People have been previewing Conroe performance for a while, because they got processors without going through Intel. Some were upset that they couldn't do articles because they didn't want to put in the time or effort trying to get a chip through other sources. By moving up the NDA lift date, Intel now allows all of the web sites to talk about Core 2 Duo in the open.
Anyway, it's all a marketing war right now, and both AMD and Intel are guilty. Where are the Energy Efficient AMD processors? In about the same place as current Core 2 Duo chips. Basically, though, Intel is building up supply before the official availability launch as opposed to the NDA launch. We might actually be pleasant surprised by availability at the end of the month.
Shintai - Saturday, July 15, 2006 - link
How can it be a paperlaunch if they haven´t launched yet? Launch is still july 27th.Having sites test an upcoming product is a whole other matter.
And just because some can buy B2 stepping retail Core 2 Duos from sites already shipping them means nothing.
Here is a pic of a retail X6800 btw ;)
http://80.167.217.210/pics/e6800.jpg">http://80.167.217.210/pics/e6800.jpg