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    Asynchronous RAM in my 6920G

    Discussion in 'Acer' started by Big_Rich_UK, Sep 22, 2009.

  1. Big_Rich_UK

    Big_Rich_UK Notebook Enthusiast

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    My T9300 800MT/s 6920G has 4Gb of PC-5300 DDR2 RAM @ 5-5-5-15 @ 667mhz.

    CPUID reports this as being 3:5 Asynchronous with my FSB, which I know makes me take a big performance hit.

    If I got hold of 4Gb of PC-6400 DDR2 RAM with similar cas/ras timings, will I benefit from a performance increase? I read somewhere that having DDR2 RAM running at double (1:2) your FSB is the best for performance, especially on C2D chips.

    As there is no way of setting up RAM speeds and timings in the BIOS, would it autodetect the change from PC-5300 to PC-6400 and switch from 3:5 to 1:2 automatically?

    Why have Acer crippled an 800MT/s system with PC-5300 RAM in the first place?
     
    Big_Rich_UK, Sep 22, 2009
    #1
  2. moral hazard

    moral hazard Notebook Nobel Laureate

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    what chipset do you have?

    If it's an older one like PM965 then you cant run memory any higher than 667mhz.

    BTW to change timmings and other things you can flash your ram with SPDtool and thaiphoon burner.
    But if you flash bad timmings then it's not really easy to save the ram.
     
    moral hazard, Sep 22, 2009
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  3. DarkSilver

    DarkSilver MSI Afterburner

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    But the motherboard PM-965 can't read more than @ 5-5-5-15 @ 667mhz.
    If you buy a RAM with higher speed or OC your RAM, the PM-965 will auto downlock it to @ 5-5-5-15 @ 667mhz.
    So, I think it is pointless to OC the RAM.
     
    DarkSilver, Sep 22, 2009
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  4. Big_Rich_UK

    Big_Rich_UK Notebook Enthusiast

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    Ah right :(

    Yeah, it's the PM965 chipset.

    I didn't realise it couldn't do more than 5-5-5-15 @ 667Mhz.

    It's already running 5-5-5-15 @ 667Mhz so I take it my RAM is totally maxed out?
     
    Big_Rich_UK, Sep 22, 2009
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  5. DarkSilver

    DarkSilver MSI Afterburner

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    The RAM can be OCed but it is pointless because the motherboard only can use the maximal speed of 5-5-5-15 @ 667Mhz. You can try to buy a faster RAM card and put into your PM965. You will see the RAM you inserted will downclock itself to 5-5-5-15 @ 667Mhz.
    If you change your motherboard to a stronger 1, you can OC the RAM without the motherboard downclock it again.
     
    DarkSilver, Sep 22, 2009
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  6. sgogeta4

    sgogeta4 Notebook Nobel Laureate

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    Even if you could change it, the performance difference wouldn't be noticeable.
     
    sgogeta4, Sep 22, 2009
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  7. mistermojo

    mistermojo Notebook Enthusiast

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    so your saying a cas4 4-4-4-12 667 stick doesnt work at full speed and clocks down to cas5 5-5-5-15 timmings? havent seen anyone reportin this problem before.

    im looking to fit 4gb cas4. from http://www.cclonline.com/product-info.asp?product_id=24444&tid=frooct

    seems like the max performance return you would ever get is like 1%-2%.

    but if you want the 6920g pimped to the max, its a option..
     
    mistermojo, Oct 30, 2009
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  8. TehSuigi

    TehSuigi Notebook Virtuoso

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    DarkSilver, you can get DDR2-667 RAM modules with stock timings of 4-4-4-12. Unless you have evidence to the contrary, they should work just fine.
    Then again, we're talking performance boosts of less then 3%. Don't bother.

    Big Rich, the performance hit by asynchronous FSB :DRAM frequencies is not exactly material. Modern systems can accomodate asynch RAM just fine.
     
    TehSuigi, Oct 30, 2009
    #8