2.93GHz with DDR2-1067 Performance Comparison
It is clear enough that despite the poorer memory bandwidth, Core 2 Duo is the performance leader by a substantial margin at stock speeds. You have seen that in all of the results posted in this article. This conclusion will not satisfy all our readers, however. Many have theorized every incarnation of performance imaginable with AM2 having higher clock speed, higher bandwidth, or higher speed memory than it currently does.
To best answer these questions we put together the fairest comparison we could think of to directly compare Core 2 Duo and AMD AM2. This consists of running both processors at the exact same speed - 2.93GHz - achieved at the same ratios - 11x266. This involves overclocking the AM2 FX62 to 2.93GHz and raising the "bus" speed to 266. That allows an 11x266 ratio to match Core 2 Duo. The desirable side effect is that while AM2 does not really support DDR2-1067, by setting the memory to DDR2-800 we reach DDR2-1067 speed at the 266 speed setting. While this slightly stacks the deck in AMD's favor, it is as close as it is possible to get at running the two systems at the same speed, same memory timings, same memory voltages, same memory, and same video card. We are comparing two identically configured systems with AM2 powering one system and Core 2 Duo powering the other system.
Results are particularly interesting in that the fastest current AM2 processor, the FX62, is overclocked about 5% in CPU speed and 33% in "bus" speed over a stock AM2 system.
Frankly the gap that remains in Super Pi results when comparing AM2 and Core 2 Duo at the same speed was something of a shock. Clock for clock, with all other variables the same, Core 2 Duo is still almost 60% faster than AM2. There is nothing complex about calculating the value of Pi to 2 million places, but it does show the true power of Conroe in computation-intensive tasks.
Despite the improvements Intel has made in intelligent read-ahead for memory, AM2 still has a huge lead in buffered memory bandwidth. This is a result of the superior on-processor memory controller used on AM2. The results become much closer in Unbuffered memory results, which is normally more revealing of performance in real-world applications, but AM2 still has a wider memory bandwidth. The unfortunate reality is AM2 is not starved for memory bandwidth and cannot really make effective use of this advantage. AMD clearly knows how to deliver memory bandwidth, so the task now becomes to modify their core logic to make better use of this advantage.
We can now say with authority that Core 2 Duo is the faster performer clock-for-clock across the board. At the same 2.93GHz Far Cry is 27.7% faster, Half-Life 2: Lost Coast is 12.4% faster, and Quake 4 is 22.2% faster on Core 2 Duo. Of course AMD does not currently have a 2.93GHz CPU, so we tested by overclocking FX62. This suggests that FX64, or whatever it will be called, will not help much at 3.0GHz with a 200 clock speed.
It is clear enough that despite the poorer memory bandwidth, Core 2 Duo is the performance leader by a substantial margin at stock speeds. You have seen that in all of the results posted in this article. This conclusion will not satisfy all our readers, however. Many have theorized every incarnation of performance imaginable with AM2 having higher clock speed, higher bandwidth, or higher speed memory than it currently does.
To best answer these questions we put together the fairest comparison we could think of to directly compare Core 2 Duo and AMD AM2. This consists of running both processors at the exact same speed - 2.93GHz - achieved at the same ratios - 11x266. This involves overclocking the AM2 FX62 to 2.93GHz and raising the "bus" speed to 266. That allows an 11x266 ratio to match Core 2 Duo. The desirable side effect is that while AM2 does not really support DDR2-1067, by setting the memory to DDR2-800 we reach DDR2-1067 speed at the 266 speed setting. While this slightly stacks the deck in AMD's favor, it is as close as it is possible to get at running the two systems at the same speed, same memory timings, same memory voltages, same memory, and same video card. We are comparing two identically configured systems with AM2 powering one system and Core 2 Duo powering the other system.
Results are particularly interesting in that the fastest current AM2 processor, the FX62, is overclocked about 5% in CPU speed and 33% in "bus" speed over a stock AM2 system.
Frankly the gap that remains in Super Pi results when comparing AM2 and Core 2 Duo at the same speed was something of a shock. Clock for clock, with all other variables the same, Core 2 Duo is still almost 60% faster than AM2. There is nothing complex about calculating the value of Pi to 2 million places, but it does show the true power of Conroe in computation-intensive tasks.
Despite the improvements Intel has made in intelligent read-ahead for memory, AM2 still has a huge lead in buffered memory bandwidth. This is a result of the superior on-processor memory controller used on AM2. The results become much closer in Unbuffered memory results, which is normally more revealing of performance in real-world applications, but AM2 still has a wider memory bandwidth. The unfortunate reality is AM2 is not starved for memory bandwidth and cannot really make effective use of this advantage. AMD clearly knows how to deliver memory bandwidth, so the task now becomes to modify their core logic to make better use of this advantage.
We can now say with authority that Core 2 Duo is the faster performer clock-for-clock across the board. At the same 2.93GHz Far Cry is 27.7% faster, Half-Life 2: Lost Coast is 12.4% faster, and Quake 4 is 22.2% faster on Core 2 Duo. Of course AMD does not currently have a 2.93GHz CPU, so we tested by overclocking FX62. This suggests that FX64, or whatever it will be called, will not help much at 3.0GHz with a 200 clock speed.
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Zebo - Tuesday, July 25, 2006 - link
Nice one Wes and it makes sense no matter what to have memory testing done on the top dog platform, Conroe.Mclendo06 - Tuesday, July 25, 2006 - link
Is there any reason that either company, Intel or AMD, couldn't design a future processor both with an intelligent pre-fetching algorithm such as is seen in the Core 2 Duo and an on-die memory controller like on the AM2 processors? Seems like the apparent memory latencies could be dropped very significantly by combining these features.Calin - Tuesday, July 25, 2006 - link
We are hoping in the next big update to AMD processor (the K8L) to have some kind of intelligent prefetching (it is entirely possible, but it costs a number of transistors). Possibly that "intelligent prefetching" means reordering loads from memory, and this happens before the memory controllerIngas - Tuesday, July 25, 2006 - link
How can Core 2 Duo do prefetch before memory controller?
I miss some point, do I?
Calin - Wednesday, July 26, 2006 - link
I wasn't clear enough. The memory controller gets requests for memory, and returns that memory. Nothing more, nothing less.All the logic for preordering is housed in the proper microprocessor, and not in the memory controller - as such, it has no relation with the integrated/discrete implementation of the memory controller.
vailr - Tuesday, July 25, 2006 - link
Has anyone run: a Core2 Duo CPU comparison of DDR vs. DDR2, running on the ASrock 775Dual-VSTA? To determine how much slowdown would occur, by using the older DDR memory?Ingas - Tuesday, July 25, 2006 - link
Interesting point!Maybe Core intelligent look-ahead so intelligent, that it even performs equaly on DDR!
Hm.
Very interesting!
Gary Key - Tuesday, July 25, 2006 - link
We will show this in our review. ASRock just released bios 1.4 that addressed a few issues we noticed in our preview of the board.photoguy99 - Tuesday, July 25, 2006 - link
...that AMD is thoroughly owned.It's amazing the arguments have still persisted up until now about excuses for Core2 doing so well.
It was mentioned that AMD survived before at the lower end of the market - but remember how much trouble they had? There were losing money all the time back then. Now they have taken *all* of their 2.5B cash reserve and spent it on ATI. Nice.
It hurt AMD's credibility even more when Dirk Diggler recently said 4x4 was going to be an answer to Core2. Right. After 30 years of dual socket systems being a niche they are finally going to take off and save you - good luck with that.
duploxxx - Tuesday, July 25, 2006 - link
because you have no idea what is going behind the scene and only looking at performance of a desktop cpu and think this is the real world.almost no review site is proud enough to get up against the hyping marketing machine from intel. well then believe the marketing hype and own a cpu that has a crapy design when it comes to real multithread and 64bit. way to go to the future knowing vista is comming your way.
multicore/multisocket is the future, even intel knows it.
amd is in a much stronger position know and by the end of this year the make procs with a price tag 50% lower than intel intel can only counter this by going to 45nm end of 2007. knowing the cost of all the intel crew, fabs and size of the processors.