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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  • vaystrem - Tuesday, May 15, 2007 - link

    Thank you for your response :)
  • cool - Tuesday, May 15, 2007 - link

    What am I missing? How can you have DDR2 800 results for the DDR3 Bearlake mobo?
    Look at the 3rd row, 4 column of the Sandra benchmarks results on page 5.
  • TA152H - Tuesday, May 15, 2007 - link

    Their chart is a little bit off. It is how they did their best to speed normalize DDR2 and DDR3, so for the DDR2 column for the Bearlake it is DDR2 memory they tested, for the DDR3 version, it is DDR3 memory.

    It's probably the most useful thing in there, in my opinion. It shows you get extra speed even at the exact same timings, with memory using lower voltage. It's pretty impressive.
  • cmdrdredd - Tuesday, May 15, 2007 - link

    not very impressive to me considering the prices you'll be paying. That's $300 difference between a good DDR2 kit and a DDR3 kit (probably not even high bin or binned at all).
  • TA152H - Tuesday, May 15, 2007 - link

    Well, agreed, currently you're not getting much bang for the buck, but that's always the case when new memory comes out. Look at the price of RDRAM, it never got better :P.

    But, obviously, the prices today mean essentially nothing for the future of the technology, it's just representative of it being a very new technology right now. I'd expect it should be a tiny bit more expensive everything else being equal because some of the additions to it, but it should be insignificant. It's a much cleaner design, and you get some performance on top of it, so I think it's a good technology. I agree, for now, it's difficult to validate the price of it. It's not even like you could say that you're better off getting a DDR3 based design now so you can reuse the RAM. The latencies are so poor on the current stuff you'd probably be aghast at using it a year from now, and you'd probably be able to buy 1 GB of DDR2 today, and 1 GB of DDR3 in a year for less than 1 GB today. So, right now, I don't think it makes much sense to anyone.

    Good thing for Intel pushing it though. Anyone that dislikes them needs to recognize how important they are for moving technology forward even at their own cost. Sometimes they've failed though, such as with RDRAM and, so far, EPIC.
  • Wesley Fink - Tuesday, May 15, 2007 - link

    DDR3 will run at DDR3-800 6-6-6-15 timings. We will add this to the DDR-800 5/6-6-6- line to clarify. The point was to run all 3 boards and the two memories at the exact same speed and timings. 800 was the only speed that allowed this.
  • cool - Tuesday, May 15, 2007 - link

    Thanks for the explanation, Wesley.
    I was confused thinking the P5K3 was maybe one of those motherboards that can take 2 types of different RAM, namely DDR2 and DDR3. But that is not the case.
  • TA152H - Tuesday, May 15, 2007 - link

    I see timings of 5/6-6-6-15 and such. What does 5/6 mean? The P965 is running at five and the others at six?
  • Wesley Fink - Tuesday, May 15, 2007 - link

    We added this clarification to Page 4 - Memory Test Configuration:

    "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."
  • TA152H - Tuesday, May 15, 2007 - link

    That's clear, I think that will remove any questions relating to the charts.

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