Intel P965: DDR2-667 Memory Performance

by Gary Key on 10/26/2006 9:00 PM EST
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  • markolsen - Sunday, October 29, 2006 - link

    Ok I'm new to this, so forgive me if it's a silly question, but why haven't you included Geil DDR2-667 memory in the comparison? Reply
  • KHysiek - Saturday, October 28, 2006 - link

    There is no such memory on ADATA www page, there is just different numbering scheme. So whay memory is this? Reply
  • Afrd2shtstrngerS - Friday, October 27, 2006 - link

    Hi Gary,
    Good article! I have been trying to solve the mystery of dividers/strapping after amd64's but not succeeded yet. I can run my e6400 @ 3.8ghz 1:1 (small fft's for 12.5 hrs) with the ocz 6400 platinum rev2 (hope you will include this ram for your next article) at 1.6vcore (http://img95.imageshack.us/img95/5111/38088x476160...">http://img95.imageshack.us/img95/5111/38088x476160... but it is not stable in blend run (8x476 1:1). I was wondering what did you change in ds3 bios to get 5:4 divider (changed system multiplier to 2.5?). Thanks...
    Reply
  • Afrd2shtstrngerS - Friday, October 27, 2006 - link

    I think you need to copy-paste the image link to open in a browser - still couldnt learn how to supply correct links! Reply
  • jackalsmith - Friday, October 27, 2006 - link

    Nice work on the article. However, if you really want some great memory for the price there is some ram from crucial that uses D9 ic and it's only $229 for 2gb! This is just binned lower but can run at ddr800 speeds at cas 3 as long as you have the voltage to push it. http://www.newegg.com/Product/Product.asp?Item=N82...">http://www.newegg.com/Product/Product.asp?Item=N82...
    I can get mine to run ddr1000 4-4-4- and ddr1200 5-5-5-.
    Reply
  • Gary Key - Friday, October 27, 2006 - link

    We just received that memory for testing. I have already recommended it to a few readers on the forums. In our next memory short story I will include the Crucial along with some SuperTalent and OCZ DDR2-667 that we received yesterday. I also have some revised A-DATA DDR2-533 that hit DDR2-970. ;-) Reply
  • SocrPlyr - Friday, October 27, 2006 - link

    I wish they could have reviewed a single stick of RAM that met the DDR2 spec.

    Josh
    Reply
  • SocrPlyr - Friday, October 27, 2006 - link

    I stated that wrong... I am too tired and my posting privileges should be revoked. Reply
  • deathwalker - Friday, October 27, 2006 - link

    I sure hope there are some MicroATX boards in you upcoming reviews. :) Reply
  • VooDooAddict - Friday, October 27, 2006 - link

    Agreed Reply
  • Gary Key - Friday, October 27, 2006 - link

    I can already tell you that our mATX board roundup will include a lot more AM2 boards than Intel at this time. We finally have some good BIOS releases on a couple of our Core 2 Duo capable mATX boards that are worth testing now. Still do not know when NV will release an updated NF61S board for C2D. Reply
  • kmmatney - Friday, October 27, 2006 - link

    So, what gives the best bang for buck for overclocking?

    Option 1) Slower E6300 cpu with more expensive memory that overclocks better

    Option 2) A more expensive E6400 with a higher multipler, and slower, cheaper memory?

    It sounds like your better off getting a more expensive cpu with a higher multiplier, instead of more expensive RAM.
    Reply
  • JarredWalton - Friday, October 27, 2006 - link

    I would typically go with the E6400 over the E6300 as it offers more flexibility overall. Hmmm... maybe that's why I bought one? :) 8X vs. 7X helps a lot. 3.6 GHz requires DDR2-900 and 450 FSB with the E6400, which is pretty reasonable. The same CPU speed with E6300 would require RAM that can run at over DDR2-1000 (DDR2-1028 to be exact). *MUCH* more expensive for that sort of RAM. Reply
  • xsilver - Friday, October 27, 2006 - link

    what about the option of using ratio's on a e6300 and using the cheaper ram?
    what kind of performance hit is to be expected?
    Reply
  • kmmatney - Friday, October 27, 2006 - link

    Thanks. Makes sense to me. Reply
  • yyrkoon - Friday, October 27, 2006 - link

    Heya Jarred, according to a buddie of mine, even multipliers on CPUs is prefferable. He claims that odd CPU multipliers is in efficient, and actualy underperforms even numbered multipliers . . . I've NEVER heard of this before, but this doesnt mean its not true, and I've never done any testing here myself.

    Also, I was curious , when does memory timings make a real world difference ? Memory SPEED (ie running 1:1 vs any other ratio ) I would think would be the biggy. Here, I've done some testing, and to be honest, outside of 'benchmarking for a living' I honestly havent noticed much, if any difference.
    Reply
  • Aikouka - Friday, October 27, 2006 - link

    Timings tend to make a difference in almost any memory hungry application. However, the one thing to keep in mind is that not all memory timings will have a great effect or any effect at all. The two main values that are best taken into consideration are CAS latency and Command Time (not usually shown when buying memory). CAS latency is always taken into consideration, regardless of what memory address you're accessing. Command Time can generally speed up your system as it defines how long a command should be sent to the memory module for. If it's lower, then another command can be sent sooner.

    Most of the other timings deal with rows and how long it takes to switch from getting a row into the buffer to finding the column (tRCD), how long for a row to be brought into the buffer (tRP) and how short can the duration be of a row sitting in memory (tRAS).
    Reply
  • JarredWalton - Friday, October 27, 2006 - link

    Regarding even vs. odd multipliers, it's not more or less efficient, but merely an impact on memory speed... but not with Intel or Core 2 Duo. AMD's socket AM2 (and 939 and 754) derive memory speed from the CPU speed, so a 3000+ AM2/939 chip has a 9X multiplier and a 200 MHz base HyperTransport bus speed, giving 1800 MHz. Back in the DDR world, you also had PC-3200 RAM running at a 200 MHz bus, so multipliers didn't matter. With AM2, things change a bit.

    The same 3000+ has a 9X multiplier, but where a CPU/9 divider would give DDR2-400, that's now slow memory. If you want DDR2-533, how do you divide 1800 by a whole number to get a 266 MHz base bus speed? Answer: you can't. So you come close: 1800/7 = 257, so if you have a 3000+ and you set the RAM for DDR2-533, you really get DDR2-514. It's doubtful that you would notice the loss of 19MHz of RAM bandwidth, but it's still there. For DDR2-667, you also can't evenly divide 1800 to get 333, so you end up with CPU/6 = 300, or DDR2-600. In that case you lose 67MHz of RAM bandwidth. Finally, DDR2-800 ends up using CPU/5 = 360 = DDR2-720, a loss of 80MHz of potential bandwidth.

    Now, here's why even multipliers are "better". You can always get DDR2-800 memory speed with an even multiplier, as you simply divide the CPU speed by half the CPU multiplier. 2000 MHz (X2 3800+ or 64 3200+) uses a 10X multiplier, so CPU/5 = 400. 2000 also happens to work well with DDR2-667 as CPU/6 = 333, so you end up with exactly DDR2-667. For DDR2-533 you get CPU/8 = 250 or DDR2-500.

    Not all even multipliers work exactly with DDR2-667, but they all will give you DDR2-800. The 2400MHz chips also give DDR2-533 exactly via CPU/9. In general, I think even multipliers have a better chance of coming close to the rated memory speeds, but it's really not a huge issue as AMD isn't typically bandwidth constrained.

    As for Intel, they derive memory speed from the bus speed using ratios rather than going from CPU speed, so with a 266MHz base FSB you always have 1:1 giving DDR2-533, 4:5 gives DDR2-667, and 2:3 gives DDR2-800. You can also go 1:2 for DDR2-1066 if the motherboard supports it.

    If the memory timings are equal, in almost all cases higher bandwidth will be equal or better. Core 2 does make one small change, however, as if you overclock past a 500 MHz base bus speed (I think that's right) the chipset bootstrap changes. Normally, the chipset runs at the FSB speed, so overclocking improves chipset performance as well. At 500MHz the chipset reduces speed assuming you're using 1333FSB instead of 1066FSB. Something like that - Gary could explain it better. Basically, there's a point at which the chipset speed is reduced and so even if the bus is 20 MHz faster you might actually get slower performance. Without extreme overclocking, this is rarely a concern.
    Reply
  • imaheadcase - Friday, October 27, 2006 - link

    From looks of prices of it..you might of found something more expensive than ram for a "budget" system :P Reply
  • Madellga - Friday, October 27, 2006 - link

    Hi Gary, nice article as usual.

    The irony is that prices started to drop in Europe. They surged 50% and more between August and end of September, but there was a substantial price drop in the last 10 days: from 15 to 30%, depending on the brand and speed.

    Take care.
    Reply
  • anandtech02148 - Friday, October 27, 2006 - link

    All of a sudden this type of memory disappeared from reviews. Unfortunately i found the best bargain out of this before the memory crisis, i bought 2gig pqi for $127.00.
    if you search hard enough you can find this type of mem for 45buxs 512mb. Unlike the stuff you see review on anandtech, the price are outrageous compare this type, my question is
    Am i stuck with 4gig worth of junks?
    Reply
  • stmok - Thursday, October 26, 2006 - link

    I was wondering about DDR2 667 RAM, but thanks for confirming with your test.

    I think I'll go for something like E6400 and overclock to 3.2Ghz (8x 400)...
    Reply
  • falc0ne - Saturday, October 28, 2006 - link

    yeah I was thinking about the same thing. First I will try to see how far can I go and then I will come back to a safer setting, a decent OC Reply
  • Sunrise089 - Thursday, October 26, 2006 - link

    "On our P965 motherboards we generally see that DDR2-667 timings are perfectly acceptable with the best overall performance being at DDR2-800 when not overclocking the system."

    -Does this only refer to memory timings having a larger impact at OC'd cloclspeeds, or will a Core 2 Duo system not be able to overclock as well with DDR2-667? How much less performance can we expect when overclocking? I assume the ammount (or hopefully lack-there-of) of OC limitation would be the determining factor as to whether or not this memory really is a substitute to DDR2-800.
    Reply
  • Gary Key - Thursday, October 26, 2006 - link

    I corrected the wording in this section. It should make sense now. ;-)

    We have not seen any affordable DDR2-667 reach DDR2-1000 or better speeds. We have some Corsair PC6400C3, GEIL Ultra, and OCZ memory that will do it but the prices are about $550 for 2GB currently. The majority of DDR2-800 we have tested has made it to DDR2-1000 or better which allows you some headroom for lower timings in the DDR2-900~1000 (450FSB~500FSB) range. These lower timings at the higher FSB rates will improve performance in certain situations by a couple of percent or better. You need this capability when overclocking a E6300 above 500FSB at a 1:1 ratio. However, the differences require benchmarks to notice. Unless you plan on benchmarking for a living then any real performance differences between 4-4-4-12 or 5-5-5-15 at 7x500FSB are really minimal. You can expect several DDR2-667 modules to reach DDR2-900 or better as we have shown. However, we were at the bleeding edge in several cases so we suggest good DDR2-800 when overclocking the Core 2 Duo family past 450FSB on the P965 chipset.
    Reply
  • ShizNet - Thursday, October 26, 2006 - link

    GREAT JOB!
    what a write up.. everyOne is just SHOKED by your article.. trust me i'm one of them - what an eye-opener

    thx for your tip on Opera 9.x - i found short-cut [F12] for same solution

    cheers!
    Reply

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