What memory to choose for a 2.4C (Costa Rica, SL6Z3), IC7 Max3 and Thermalright SP-94???

Discussion in 'Abit' started by Brian Madsen, Oct 31, 2003.

  1. Brian Madsen

    Brian Madsen Guest


    I have recently bought these components for my new rig. But I'm still
    missing the memory - I can't decide what to buy!

    At first I was planning a 3.6 GHz overclock with the 5:4 DRAM ratio. That
    would give a memory speed of 240 MHz. I concluded that the OCZ EL DDR PC3700
    Dual Channel Gold would be the memory to get. I think it is reasonable to
    expect a 7 MHz overclock at default 2-3-3-7 timings. Have heard of other
    people running a SL6Z3 at 3.6 GHz with a SP-94.

    But now I'm having second thoughts. I know that a memory ratio of 1:1 is to
    be preferred due to synchronous speeds. But with which memory can I expect a
    decent OC, @+3.2 GHz? Should I look at OCZ PC4000 Dual Channel Gold or OCZ
    PC4200 Premier Dual Channel?

    I have read the article at
    http://www.tomshardware.com/motherboard/20030812/index.html and the forums
    at Abit's website and at Overclockers.com. I'll be a bit disappointed if I
    end up with some PC4200 memory, which can't go significantly faster than 267

    Any advice/comments/suggestions.


    Brian Madsen
    Brian Madsen, Oct 31, 2003
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  2. Brian Madsen

    Skid Guest

    I understand your problem, but you're going to have a hard time finding any
    ram that will reliably overclock a 2.4 to 3.2+ at 1:1. If you did, the
    higher latency would kill most of the gain you'd get by running synchronous,
    and you still wouldn't be pushing the cpu to the max.

    Check the Abit forums at http://forum.abit-usa.com/ and you'll see most
    people overclocking 2.4s opt for the lowest latency ram they can run at 5:4
    and push the fsb until the cpu squeals.

    On my IC7, I'm running Buffalo Tech PC3700 (same Winbond BH-5 modules as
    Mushkin PC3500 Level II Black, but lots cheaper.)

    Running 5:4, 275/220. CPU is 3.3 ghz, memory at 2,3,2,6. 100% stable and
    fast enough for any sane person. Me, I'd like a little more ;>)
    Skid, Oct 31, 2003
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  3. Brian Madsen

    Brian Madsen Guest

    Quote Toms Hardware

    "A mere 3 MHz of extra FSB speed is enough to outperform the optimized
    system with run-of-the-mill timings, bla bla bla...."

    As I understand this statement, a higher fsb is to be preferred rather than
    tighter rimings.

    The question narrows down to which of these two setups is the fastest (in
    every day use):
    A 2.4c overclocked to 3.6 GHz with a DRAM ratio of 5:4 with DDR at 240 MHz
    with timings of 2-2-2-5 or a 2.4c overclocked to 3.36 GHz with a DRAM ratio
    of 1:1 with DDR at 280 MHz with timings of 3-3-4-7.

    Brian Madsen
    Brian Madsen, Nov 3, 2003
  4. Brian Madsen

    Skid Guest

    The Tom's Hardware review is all but irrelevant to this discussion, as he
    only used two test setups -- a stock 3.2g 1:1 at 200 fsb and an overclocked
    2.6 running 1:1 at 250 fsb. It doesn't take a rocket scientist to figure out
    which will come out ahead in that race, as the second system has a small
    edge in cpu speed and a huge advantage in memory bandwidth.

    I can tell you that my system running 5:4, 275/220, at 3.3 ghz, 2,3,2,6,
    turns in
    better scores across the board than either of the systems in that test.

    Most of the standard reviews of mobos and memory fail to compare using
    different cpu/ram ratios. But if you'll check the forums at
    Tom's, or www.anandtech.com, or www.overclockers.com or www.hardocp.com or
    www.forums.abit-usa.com you'll find a lot of individual benchmarks and a
    general consensus.

    All things being equal, 1:1 offers better performance than 5:4. But the ram
    is the limiting factor, especially when you're working with a 2.4 or 2.6
    with a low multiplier.

    In my experience, if you can get the fsb just 6-7 mhz higher using 5:4,
    you'll get better overall performance than at 1:1.

    Not only that, but if the ram you need to run 1:1 at 250 or above is CAS 2.5
    or 3, you can often get higher memory benchmarks running 5:4 at CAS 2.

    All these reasons -- plus the high cost of PC4000-4200 -- help explain why a
    lot of experienced overclockers go for memory that will run tight timings at
    210-240 mhz and push the cpu to its limits at 5:4.

    Here is a graphic from a review that shows one factor in the equation:


    The top two bars show Sandra memory benchmarks for a 3.2g P4 running 1:1 at
    200 vs. a 3.0 running at 5:4. Both are using the same PC 3200 running the
    stock 200 mhz with the same timings.

    Guess which is higher? Also note how much benefit the 3.0 gets over the same
    cpu at stock 1:1 because of the faster cpu bus, without bumping the memory
    speed at all.

    The key to answering the hypothetical you pose is the phrase "in everyday
    use." Most games and benchmarks depend most on cpu speed, and if you can get
    the cpu higher at 5:4 it's going to score higher in almost everything but
    memory benchmarks.
    Skid, Nov 3, 2003
  5. Brian Madsen

    Brian Madsen Guest

    The Tom's Hardware review is all but irrelevant to this discussion, as he
    Oohh, I've missed that fact.

    Thanks a lot for this explanation. It answers most of my questions.

    But what memory do You recommend, Skid? It must be able to run at 240 MHz
    with the tightest possible timings. I live in Europe, so the accessibility
    isn't the best.

    Brian Madsen, Nov 4, 2003
  6. Brian Madsen

    Skid Guest

    That's a very tall order. I suggest you read the memory reviews at
    www.amdboard.com (ignore the AMD part, they compile reviews from all over on
    both platforms) and check the forums at www.forums.abit-usa.com to see what
    others are using on the same board.

    I really like my Buffalo Tech PC3700, but with the 2.8v limit on my IC7 I
    can't get it much past 220 at CAS 2, or 225 at CAS 2.5 without occasional
    errors. That is fine for me, because my 2.4 also gets squirrely at much
    above 3.3ghz.

    At 275/220 everything is 100% rock solid.

    Maybe the extra voltage headroom on the MAX would help, or maybe there's ram
    out there with more headroom. I can't recommend what I haven't tried.

    Happy hunting.
    Skid, Nov 4, 2003
  7. Brian Madsen

    Brian Madsen Guest

    Found some Mushkin PC-3500 Level II Dual Pack with SPD timings of 2-3-2-6
    for Intel chipsets (875 or 865) and 2-2-2-6 for nForce2. I have read of some
    people running it at 2-2-2-5 at 240 MHz - are they just really lucky, or
    could I also expect this. I believe these modules utilize the Winbond BH-5
    chips, which should perform really well in Intel rigs.

    Just to sum up:

    Buffalo PC3700, CAS Latency of 3.
    Corsairs XMS 3700 has timings of 3-4-4-8.
    Geil PC-3700 has timings of 2.5-3-3-7.
    Kingston HyperX 3700 has timings of 3-4-4-8.
    Kingston HyperX 3500 has timings of 2-3-3-7. The reviews I have read aren't
    that impressive, though.
    OCZ EL DDR PC-3700 Dual Channel Gold has timings of 2-3-3-7.

    At the moment Mushkin PC-3500 Level II or OCZ PC-3700 Gold are the best

    Brian Madsen, Nov 6, 2003
  8. Brian Madsen

    Skid Guest

    You can't always judge by the manufacturer's recommended timings, some are
    very conservative to guarantee stability, others are artificially loose to
    allow higher speed ratings. Some bait and switch, with one set of timings
    built into the SPD for compatibility, and another "recommended" set for
    those who want better performance.

    The result, which adds still another layer of complexity to ram shopping, is
    that many sticks can run tighter timings at lower speeds, others can't.

    Two cheap examples:

    Crucial adheres faithfully to the JEDEC spec for PC3200 and recommends CAS
    3, but can almost always run 2.5 and clocks as high as some PC3500.

    Buffalo Tech PC3700 has the same Winbond BH-5 as Mushkin PC3500, and on my
    IC7 runs the same 2,3,2,6 at 220+ mhz. It needs 2.5 or 3 to get to 230+, and
    I don't really know how high it can go because my board can't feed it more
    than 2.8v and my cpu is maxed out using the 5:4 ratio.

    Mushkin is really good stuff, though expensive. Even so, I have a hard time
    believing 2,2,2,5 at 240, heat spreaders or not.

    Meanwhile most of the so-called PC4000 sticks flat won't run below CAS 3.

    It's interesting, but not surprising, that both the top two choices on your
    list use memory modules originally certified for 200 mhz. OCZ cherry picks
    Samsung chips and grinds off the top layer to improve heat transfer. Mushkin
    bought out what was left of the discontinued BH-5 and bumped it up the same
    way overclockers had been doing when it was commonly sold as PC3200.

    Like the old carney says, "You pays your money, and you takes your chance."
    Skid, Nov 6, 2003
  9. Brian Madsen

    Brian Madsen Guest

    I think I'm going for the OCZ EL DDR PC-3500 Dual Channel Platinum Limited
    Edition. Anandtech managed to OC it to 466 MHz DDR with CLs 2-2-3-8. At 433
    MHz DDR it was at 2-2-2-5.

    Brian Madsen, Nov 6, 2003
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