DDR3 vs. DDR2

by Wesley Fink on May 15, 2007 2:40 PM EST
Memory Test Configuration

The comparison of DDR3 and DDR2 used exactly the same components in the same test bed wherever possible. For the fairest comparison to the P35, both the P5K and P5K3 motherboards were powered by an Intel E6420 processor running at a 1333 FSB (333 quad pumped). All that was required to do this was increase the base CPU bus to 333, leaving the default multiplier at 8. We did not even need to increase the CPU voltage and left it at the default setting. This simple setup allowed us to run the 2133MHz (8x266) Core 2 Duo E6420 at a new speed of 2666MHz. This is equivalent to an E6700 Core 2 Duo in speed. Due to issues with memory ratios on the P965 we were forced to use an E6700 for comparison. This CPU also runs at 2666MHz using a 10x266 configuration.

Memory Performance Test Configuration
Processor Intel Core 2 Duo E6420
(x2, 2.66GHz, 8x333, 4MB Unified Cache)
Intel Core 2 Duo E6700
(x2, 2.66GHz, 10x266, 4MB Unified Cache)
Intel Core 2 Quad Q6600
(x4; 2.4GHz, 9x266; 3.0GHz, 9x333; 2.66GHz, 8x333; 8MB Unified Cache)
RAM Corsair CM3X1024-1066C7
(2GB Kit - 2x1GB)
Wintec AmpX PC3-8500
(2GB Kit - 2x1GB)
Corsair Dominator CM2X1024-8888C4
(2GB Kit - 2x1GB)
Hard Drive Samsung 250GB SATA3.0Gbps (8MB Buffer)
System Platform Drivers Intel - 8.3.0.1013
Video Card Leadtek WinFast 7950GT 256MB
Video Drivers NVIDIA 93.71
CPU Cooling Intel Retail HSF
Power Supply Corsair HX620W
Motherboards ASUS P5K3 Deluxe (Intel P35 DDR3)
ASUS P5K Deluxe (Intel P35 DDR2)
ASUS P5B Deluxe (Intel P965 DDR2)
Operating System Windows XP Professional SP2
Bench Software SiSoft Sandra XI SP2
CPU-Z 1.39.4
CPU-Z 1.40
Everest 4.0
SuperPi 1.5
Far Cry - HOC River Demo

While memory timings were matched to the same memory speed wherever possible, there were a few settings where the chipsets did not allow a direct comparison. DDR3-800 runs at 6-6-6-15 timings. The P965 has options to set 6-6-6-15 timings but the board would not boot under any settings or voltage we fed it at 6-6-6 timings. The closest timings that would work on the P965 at 800 speed were 5-6-6-15. The P5K DDR2 board, based on the P35 chipset, would allow setiing and running 6-6-6-15 timings. This is reflected in our charts with the line ID of 5/6-6-6- for timings. We also tested DDR2 at the fastest timings it could achieve with complete stability on both the P5B Deluxe and P5K Deluxe. This was 3-3-3-9 at DDR2-800 and 4-4-3-11 at DDR2-1066.

It is a noteworthy advantage with the P35 chipset motherboards that every Core 2 Duo and Core 2 Quad processor we tested on the P35 boards ran at 1333 FSB speeds at the stock multiplier without the need to increase voltage. This is a significant, free, and pain-free overclock provided courtesy of the new 1333 bus speed option. The only exception to this was our top-line X6800 which did require a mild voltage boost to run at 333x11 (3.67GHz).

All of the CPUs listed above in our table are 1066 FSB processors, but all ran fine at 1333 FSB at default multiplier and default voltage. Of course this is the FSB frequency Intel will be introducing on their soon-to-be-announced processors. This little side effect will make the P35 with DDR2 a favorite overclockers' board with current Intel Core 2 Duo and Core 2 Quad processors. A $189 E6420 can perform even better than an E6700 just by selecting a 1333 bus on P35 and leaving everything else at default. Likewise, a $500 Q6600 will outperform the ~$1000 QX6700 with just a bus speed change.

This little side effect will certainly be noticed by Intel. We have to wonder how fast the 1066 processors may start disappearing with this kind of free, painless overclocking available with the new P35 boards.

DDR3 Memory and P35 motherboards Bandwidth and Memory Scaling
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  • Final Hamlet - Tuesday, May 15, 2007 - link

    Oh look! It's Bicycle repair man!
  • just4U - Wednesday, May 16, 2007 - link

    I don't really know what to think with ddr3 .. or even ddr2.

    When I jumped from PC 2700 memory (cas 3 i think) up to PC3200 memory cas 2 I noticed a increase in the overall speed of my computer.

    When I jumped to DDR2 PC5300 I noticed no speed increase. When I jumped to PC6400 I noticed no speed increase. When I overclock my memory I notice no...

    You get the picture.

    I have a question. DDR3 with tight timings, Will we accualy notice it over ddr2? Or will it be one of those things where only a benchmark tends to notice anything.
  • Starglider - Friday, May 18, 2007 - link

    Depends on what applications you're running. But based on your recent experience, probably not.
  • defter - Tuesday, May 15, 2007 - link

    The article says that P965 board was running at 1066MHz FSB and then writer is suprised when P35 + DDR2 running at 1333MHz FSB is slightly faster??? Then in the conclusion it's said that the reason for an increased performance is the chipset instead of a higher FSB???

    If you want to make P965 vs P35+DDR2 comparision, why not use the same FSB.....
  • Wesley Fink - Tuesday, May 15, 2007 - link

    The P965 was running at 10x266 or 2.66GHz. The P35 boards ran at 8x333 or 2.66GHz. 1333 is not a natural CPU ratio on the P965 so when you choose 1333 there is no way to also choose DDR2-800. At 1333 the closest you can get (at a different strap) is 833. We believe the way we tested was as close to apples to apples as we could design. Remember we are looking at MEMORY PERFOMNACE, and the FSB should not matter as long as memory speed and timings are set the same on all test boards, which we definitley insured.

    Despite that, we know that Sandra XI results can be influenced a small amount by CPU speed and possibly FSB. To make sure our results were still as close to apples to apples as possible we did run 10x266 on all boards and compared results to our test setup. The MEMORY PERFORMANCE results were virtually the same as we have reported.

    We do agree that were we testing CPU performance the differing bus speeds at the same resulatant CPU speed could make some difference.
  • IntelUser2000 - Wednesday, May 16, 2007 - link

    quote:

    Despite that, we know that Sandra XI results can be influenced a small amount by CPU speed and possibly FSB. To make sure our results were still as close to apples to apples as possible we did run 10x266 on all boards and compared results to our test setup. The MEMORY PERFORMANCE results were virtually the same as we have reported.


    Defter is right. You guys were just testing performance increase by using a 1333FSB instead of 1066FSB. Memory bandwidth tests like Sandra will show HUGE differences. Remember, the CPU will not benefit from faster memory when FSB isn't faster. It's different from AMD where Hypertransport is only used for northbridge to southbridge communications(which yields into 0% improvement ) for PC.
  • Wesley Fink - Wednesday, May 16, 2007 - link

    P35 is a combination of an increase in bus speed to 1333 and an improved memory controller. We are working on a followup article to appear in a few days that shows the breakdown of the bus speed contribution and the memory controller contribution.

    That does not change the fact that memory bandwidth for P35 is improved 16% to 18% over P965, but we have run additional tests to show the individual impact of the bus speed increase and the memory controller improvements.

    In approaching testing it is not possible to run 1333 FSB on the P965/975x and also run memory speeds like 800 and 1066 as we would like. On P35 if 1066 FSB is selected then 1333 is not available as a memory option. We can, however, run 1066 FSB on P35 to roughly determine Memory Controller contribution compared to P965, and then compare those results to 1333 equivalents (8X333 instead of 10x266) to see the additional impact of the 1333 bus on memory performance. Those results will be reported as soon as testing is complete.
  • defter - Wednesday, May 16, 2007 - link

    quote:

    1333 is not a natural CPU ratio on the P965 so when you choose 1333 there is no way to also choose DDR2-800


    Why not report results at 1066MHz FSB then?


    quote:

    Remember we are looking at MEMORY PERFOMNACE, and the FSB should not matter as long as memory speed and timings are set the same on all test boards, which we definitley insured.


    Intel's CPUs are FSB limited since memory traffic goes through FSB. For example, 1066MHz FSB can transfer 8.5GB/s while dual channel DDR2-800 can provide 12.8GB/s. Thus, increasing the FSB also affects memory performance.
  • vaystrem - Tuesday, May 15, 2007 - link

    I'm curious:
    A) Why did you chose Farcry?
    B) Why you didn't include more game tests?

    I think it would be particularly interesting to see how a game like Supreme Commander or Company of Heroes performs. In strategy games you have the stress from the graphical component and a heavy AI load which may take better advantage of all that bandwidth than a simple FPS.
  • Wesley Fink - Tuesday, May 15, 2007 - link

    This was a comparison of DDR3 and DDR2, not a launch review for P35. You will see that when the performance embargo lifts on May 21st. Far Cry is part of our standard memory test suite and we are very familiar with how it behaves with variations in memory bandwith and timings. That is why it was chosen.

    You will see test results with many more games when we review the chipset on May 21st and the new P35 motherboards on June 4th.

    Consider this a preview, and all the advance info we could give you at this point. The NDA for DDR3 memory has lifted, but the performance NDA for P35 is in place until the 21st.

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