Memory Bandwidth and Scaling
Everyone should already know that memory bandwidth improves with increases in memory speed and reductions in memory timings. To better understand the behavior of AM2 and Core 2 Duo memory bandwidth we used SiSoft Sandra 2007 Professional to provide a closer look at memory bandwidth scaling.
The most widely reported Sandra score is the Standard or Buffered memory score. This benchmark takes into account the buffering schemes like MMX, SSE, SSE2, SSE3, and other buffering tools that are used to improve memory performance. As you can clearly see in the Buffered result the AM2 on-chip memory controller holds a huge lead in bandwidth over Core 2 Duo. At DDR2-800 the AM2 lead in memory bandwidth is over 40%.
As we have been saying for years, however, the Buffered benchmark does not correlate well with real performance in games on the same computer. For that reason, our memory bandwidth tests have always included an UNBuffered Sandra memory score. The UNBuffered result turns off the buffering schemes, and we have found the results correlate well with real-world performance.
The Intel Core 2 Duo and AMD AM2 behave quite differently in UNBuferred tests. In these results AM2 and Core2 Duo are very close in memory bandwidth - much closer than in Standard tests. Core 2 Duo shows wider bandwidth below DDR2-800, but this will likely change when the AM2 controller matures and supports values below 3 in memory timings as the Core 2 Duo currently supports.
The Sandra memory score is really made up of both read and write operations. By taking a closer look at the Read and Write components we can get a clearer picture of how the two memory controllers operate. Everest from Lavalys provides benchmarking tools that can individually measure Read and Write operations.
The READ results are particularly interesting, since you can see that the READ component of Core 2 Duo performance is much larger than the WRITE results on Core 2 Duo. This is the result of the intelligent read-aheads in memory which Intel has used to lower the apparent latency of memory on the Core 2 Duo platform. Actual READ performance on Core 2 Duo now looks almost the same as AM2 to DDR2-533. AM2 starts pulling away in READ at DDR2-677 and has a slightly steeper increase slope as memory speed increases. The increases in READ speed in Core 2 Duo are a result of the intelligent read-aheads in memory. Performance without this feature would show Core 2 Duo much slower in READ operations than AM2.
This is most clearly illustrated by looking at Everest Write scores. Memory read-ahead does not help when you are writing memory, so core 2 Duo exhibits much lower WRITE performance than AM2 as we would expect. This means if all else were equal (and it isn't) the AM2 would perform much better in Memory Write tasks. Surprisingly the WRITE component of Core 2 Duo appears a straight line just below 5000 MB/s. AM2 starts at 5900 at DDR2-400 and WRITE rises to around 8000MB/s at DDR2-667. Write then appears to level off, with higher memory speeds having little to no impact on AM2 WRITE performance.
Everyone should already know that memory bandwidth improves with increases in memory speed and reductions in memory timings. To better understand the behavior of AM2 and Core 2 Duo memory bandwidth we used SiSoft Sandra 2007 Professional to provide a closer look at memory bandwidth scaling.
The most widely reported Sandra score is the Standard or Buffered memory score. This benchmark takes into account the buffering schemes like MMX, SSE, SSE2, SSE3, and other buffering tools that are used to improve memory performance. As you can clearly see in the Buffered result the AM2 on-chip memory controller holds a huge lead in bandwidth over Core 2 Duo. At DDR2-800 the AM2 lead in memory bandwidth is over 40%.
As we have been saying for years, however, the Buffered benchmark does not correlate well with real performance in games on the same computer. For that reason, our memory bandwidth tests have always included an UNBuffered Sandra memory score. The UNBuffered result turns off the buffering schemes, and we have found the results correlate well with real-world performance.
The Intel Core 2 Duo and AMD AM2 behave quite differently in UNBuferred tests. In these results AM2 and Core2 Duo are very close in memory bandwidth - much closer than in Standard tests. Core 2 Duo shows wider bandwidth below DDR2-800, but this will likely change when the AM2 controller matures and supports values below 3 in memory timings as the Core 2 Duo currently supports.
The Sandra memory score is really made up of both read and write operations. By taking a closer look at the Read and Write components we can get a clearer picture of how the two memory controllers operate. Everest from Lavalys provides benchmarking tools that can individually measure Read and Write operations.
The READ results are particularly interesting, since you can see that the READ component of Core 2 Duo performance is much larger than the WRITE results on Core 2 Duo. This is the result of the intelligent read-aheads in memory which Intel has used to lower the apparent latency of memory on the Core 2 Duo platform. Actual READ performance on Core 2 Duo now looks almost the same as AM2 to DDR2-533. AM2 starts pulling away in READ at DDR2-677 and has a slightly steeper increase slope as memory speed increases. The increases in READ speed in Core 2 Duo are a result of the intelligent read-aheads in memory. Performance without this feature would show Core 2 Duo much slower in READ operations than AM2.
This is most clearly illustrated by looking at Everest Write scores. Memory read-ahead does not help when you are writing memory, so core 2 Duo exhibits much lower WRITE performance than AM2 as we would expect. This means if all else were equal (and it isn't) the AM2 would perform much better in Memory Write tasks. Surprisingly the WRITE component of Core 2 Duo appears a straight line just below 5000 MB/s. AM2 starts at 5900 at DDR2-400 and WRITE rises to around 8000MB/s at DDR2-667. Write then appears to level off, with higher memory speeds having little to no impact on AM2 WRITE performance.
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drebo - Tuesday, July 25, 2006 - link
Excuse me, but the E6400 wasn't even IN the benchmarks Anandtech ran, but by extrapolation(considering the E6700 did not beat out the 5000+ by a large margin), it cannot perform better than the 5000+.And, in the majority of benchmarks, such as the ones http://www.anandtech.com/cpuchipsets/showdoc.aspx?...">here, which are benchmarks that have traditionally favored Intel processors in the past, the AMD chips do not fall as you paint them. They fall as I have painted them. The 4200+ outperforms the E6300 in ALL of them...and costs LESS. The 5000+ matches performance in 2/3 of them with the E6600. And costs LESS.
Sorry, but this isn't about which company is better or provides a better product. This is about which company provides a better product at a better price. We all know the X6800 is the best desktop processor available. NO ONE is disputing that. The dispute is that review sites are proclaiming that the Core 2 Duos are god's gift to Intel and that Athlon64s are completely worthless now, which is NOT the case.
In the $1k processor range, sure, Core 2 Duo is the king...but AMD doesn't have a processor in that range anymore. There is no competition to the X6800 anymore. At every other price point, however, the Athlon64 X2 processors are extremely competative.
coldpower27 - Tuesday, July 25, 2006 - link
Take a look at these benchmarks show the E6400 in them, and for the most part it beats out the 4600+http://xbitlabs.com/articles/cpu/display/core2duo-...">http://xbitlabs.com/articles/cpu/display/core2duo-...
coldpower27 - Tuesday, July 25, 2006 - link
Oh please, you looked at 1 page of benchmark to make your conclusion??Did you just look at 3D Rendering to draq your conclusions?
What about the encoding and gaming performance? Did you look at those?
IntelUser2000 - Wednesday, July 26, 2006 - link
It is obvious you haven't seen both of my posts fully. Please do. Core 2 Duo outperforms.
This is type of performance increase people would have been crazy about, but somehow its different. Maybe its conspiracy to kill Intel??
coldpower27 - Wednesday, July 26, 2006 - link
IntelUser2000.Chill. I am reply to drebo in this reply not you. Anandtech comment posting system is just strange.
IntelUser2000 - Tuesday, July 25, 2006 - link
Please stop being an idiot. If you see Anandtech's benchmarks you can clearly see that E6600 is FASTER overall than FX-62. That's why the saying of $316 FX-62 came about.
For those that are in denial about the FACT that E6600 with $316 price beats FX-62
Application Performance using SYSMark 2004 SE
Average performance: 18.6% in favor of E6600
Application Performance using PC WorldBench 5
1.4% advantage of Core 2 Duo E6600
Application Performance using Winstone 2004
2.9% advantage of FX-62, E6600 equal or faster than 5000+
3D Rendering Performance using 3dsmax 7 & CineBench 9.5
2.7% advantage of FX-62, E6600 faster than 5000+
Encoding Performance using DivX 6.1, WME9, Quicktime (H.264) & iTunes
6.0% advantage of E6600
Overall Gaming Performance
11.6% advantage of E6600
Total Performance increase of E6600 over Athlon FX-62
Core 2 Duo E6600 is 9.9% faster overall than Athlon FX-62!!
IntelUser2000 - Tuesday, July 25, 2006 - link
Normally, the kind of performance advantage E6600 gives over the FX-62 would have meant people would have flocked over to E6600 even if it was previous high-end mainstream price for Intel processors, which is $637.Stop spreading false info people(anti-intel, and i am saying lightly), cause not only your beloved Athlon 64 X2 5000+ slower than E6600, so is AMD's top end offering, the FX-62!!!
I remember people saying Core Duo was worth it(yes the Yonah). Based on the logic people are spreading for Core 2 Duo argument, Core Duo wasn't worth it at all. $637 for the top end Core Duo(Yonah), and being barely faster per clock than FX-62 when clocked outrageously high(30% over stock, while FX-62 is at stock), plus expensive motherboards that are hard to find.
If Core Duo was worth it at all, well... Core 2 Duo is like a dream.
Accord99 - Tuesday, July 25, 2006 - link
And the E6300 does better in other tests, such as the Sysmark, video encoding and games. And the E6600 doesn't compete with the 5000+, it competes with the FX-64.drebo - Tuesday, July 25, 2006 - link
I don't know what benchmarks you're looking at, but they sure as hell aren't posted on any review site I've ever seen.I never expected my opinion that AMD is not dead and Intel is not master of all to be popular, but I atleast expected some constructive responses. Yes, Intel has the best performing processor. We know this. No one cares. I'm sure AMD could spin a 3.2ghz FX-70 or something and sell it for $2000. But why bother, for 2% of the population to use? The vast majority of computer users are looking for performance-per-dollar, and there is no difference between Athlon64 X2 processors and Core 2 Duo processors in that ratio...except, of course, motherboard...which tends to cost near to twice as much on the Core 2 Duo side.
Yes, Intel released a competative platform. We're all very happy with them, and once they're available, it'll be great...but they're hardly a nail in the coffin for AMD. AMD still holds the superior chips for single-core, and performance-per-dollar is just as good as Core 2 Duo, and I can tell you from personal experience, that's what matters.
Go go objectivity!
Accord99 - Tuesday, July 25, 2006 - link
I'm just looking at all the Anandtech benchmarks. It's quite clear the E6300 is faster than the 4200+ overall, while the E6600 is faster than the FX-62 overall.So performance/dollar is higher for Conroe, the current motherboards are more expensive but that can be made up from purchasing less high-end memory. And Conroe uses less power.