Can you mix PC133 & PC100 RAM together?

Archived from groups: alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

I looked up the info for my motherboard, a SOYO SY-V6BE+ and it says it
only takes PC100 RAM (even the online manual says this). Does this mean it
won't run PC133 RAM, and can I mix 133 & 100 RAM on this board?

Who has experience doing this on their boards?
15 answers Last reply
More about pc133 pc100 together
  1. Archived from groups: alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

    "Ablang" said in news:mpfr80ls4bjfnqhn1dhvpa7sg71lf7rrn7@4ax.com:
    > I looked up the info for my motherboard, a SOYO SY-V6BE+ and it says
    > it only takes PC100 RAM (even the online manual says this). Does
    > this mean it won't run PC133 RAM, and can I mix 133 & 100 RAM on this
    > board?
    >
    > Who has experience doing this on their boards?

    The PC-133 memory just means it *could* run using a faster clock. You
    do NOT have to run it at 133MHz. It will run at 100MHz so you can mix
    PC-100 and PC-133 but it all will only run at 100MHz, the speed for the
    PC-100 memory (unless you overclock and hope the PC-100 will operate at
    the 133MHz clock rate).

    --
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  2. Archived from groups: alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

    On Mon, 26 Apr 2004 21:31:54 -0500, "*Vanguard*"
    <no-email@post-reply-in-newsgroup.invalid> wrote:

    >"Ablang" said in news:mpfr80ls4bjfnqhn1dhvpa7sg71lf7rrn7@4ax.com:
    >> I looked up the info for my motherboard, a SOYO SY-V6BE+ and it says
    >> it only takes PC100 RAM (even the online manual says this). Does
    >> this mean it won't run PC133 RAM, and can I mix 133 & 100 RAM on this
    >> board?
    >>
    >> Who has experience doing this on their boards?
    >
    >The PC-133 memory just means it *could* run using a faster clock. You
    >do NOT have to run it at 133MHz. It will run at 100MHz so you can mix
    >PC-100 and PC-133 but it all will only run at 100MHz, the speed for the
    >PC-100 memory (unless you overclock and hope the PC-100 will operate at
    >the 133MHz clock rate).

    Works fine for me.

    Regards,


    --
    Stephen Howard - Woodwind repairs & period restorations
    www.shwoodwind.co.uk
    Emails to: showard{whoisat}shwoodwind{dot}co{dot}uk
  3. Archived from groups: alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

    *Vanguard* wrote:
    > "Ablang" said in news:mpfr80ls4bjfnqhn1dhvpa7sg71lf7rrn7@4ax.com:
    >
    >>I looked up the info for my motherboard, a SOYO SY-V6BE+ and it says
    >>it only takes PC100 RAM (even the online manual says this). Does
    >>this mean it won't run PC133 RAM, and can I mix 133 & 100 RAM on this
    >>board?
    >>
    >>Who has experience doing this on their boards?
    >
    >
    > The PC-133 memory just means it *could* run using a faster clock. You
    > do NOT have to run it at 133MHz. It will run at 100MHz so you can mix
    > PC-100 and PC-133 but it all will only run at 100MHz, the speed for the
    > PC-100 memory (unless you overclock and hope the PC-100 will operate at
    > the 133MHz clock rate).
    >

    The only thing I would add to the above is the fact that much PC133
    memory is high density, and most PC100 is not. What this means is
    although the faster speed may work in your computer, your computer may
    not recognize the total size of the PC133 stick.
  4. Archived from groups: alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

    "user@domain.invalid" said in
    news:3Qrjc.51663$um3.1007845@bgtnsc04-news.ops.worldnet.att.net:
    > *Vanguard* wrote:
    >> "Ablang" said in news:mpfr80ls4bjfnqhn1dhvpa7sg71lf7rrn7@4ax.com:
    >>
    >>> I looked up the info for my motherboard, a SOYO SY-V6BE+ and it says
    >>> it only takes PC100 RAM (even the online manual says this). Does
    >>> this mean it won't run PC133 RAM, and can I mix 133 & 100 RAM on
    >>> this board?
    >>>
    >>> Who has experience doing this on their boards?
    >>
    >>
    >> The PC-133 memory just means it *could* run using a faster clock.
    >> You do NOT have to run it at 133MHz. It will run at 100MHz so you
    >> can mix PC-100 and PC-133 but it all will only run at 100MHz, the
    >> speed for the PC-100 memory (unless you overclock and hope the
    >> PC-100 will operate at the 133MHz clock rate).
    >>
    >
    > The only thing I would add to the above is the fact that much PC133
    > memory is high density, and most PC100 is not. What this means is
    > although the faster speed may work in your computer, your computer may
    > not recognize the total size of the PC133 stick.

    Higher density? What do you mean by that? The PC-100 and PC-133 that
    I've gotten in the past were both DIMMs (chips on both sides of the
    PCB). They usually look like http://snipurl.com/5znr with the 8 chips
    on the frontside (9 for ECC) and the controller chips on the backside.
    The "density" (http://snipurl.com/5zo3) remains the same for, say, a
    256MB memory stick whether it is PC-100 or PC-133.

    The chip count remains the same (8) so going higher density means going
    to a larger size memory stick, like a 128MB stick is higher density than
    a 64MB chip. Most motherboards (except really old ones) can handle
    different density modules in each slot. Some older ones required that
    you use the same density within a bank (i.e., within a pair of slots).
    You have to check what the maximum module size that the motherboard can
    handle in a slot. If it can handle modules up to 512MB and you put in a
    1GB module then you only get 512MB total and have wasted half of the
    module and your money. Also, for old motherboards, the density within a
    bank might be required to be the same for both sticks; i.e., if a bank
    is composed of 2 slots then the motherboard might require that the
    density be the same for both modules in those paired slots. It depends
    if a one or two slots comprise a bank. If a bank consisting of a slot
    pair requires the same density then just match the stick size; i.e., if
    slot 1 has a 128MB stick then put another 128MB stick in slot 2
    regardless of which was PC-100 or PC-133. Best is to read the manual
    for your motherboard to figure out what the manufacturer states are the
    limits or restrictions for memory.

    While density doesn't apply here when discussing PC-100 and PC-133, I
    have seen some modules that have a different architecture; i.e., the
    arrangement of chips is different so the distribution of them
    contributing to the bit width differs than the standard 8-chip module.
    You had to make sure within a bank to use the same architecture for both
    modules. However, I haven't personally seen this for PC-100/133 DIMMs
    (see http://snipurl.com/5zoi for pictures of standard memory module
    types) but I have seen it with SIMMs. Density goes up (for each chip on
    the PCB) as the total capacity of the memory stick goes up because the
    architecture remains the same (8 chips, 9 for ECC).

    Crucial notes that some systems won't run with a mix of PC-100 and
    PC-133 sticks (http://snipurl.com/5zoc). The most likely reason is
    probably due to SPD (serial presence detect) which reports to the
    motherboard the stick's specs. Some motherboard will detect the specs
    from the stick in the first slot and use those for all slots. So if you
    were to put the PC-133 in the first slot then the motherboard might set
    the clock rate to fast for the PC-100 in the other slot(s). Same goes
    for CAS delay: if the first stick had a CAS delay of 2 (even if it was
    PC-100) and the other slots had sticks with CAS 3 (even if PC-133) then
    the motherboard would use a CAS of 2 nanoseconds reported by the first
    stick which might be too fast for the other slower sticks. I'm not
    quite sure how the new motherboards handle a mix of specs for multiple
    sticks so I play it safe by putting the stick with the longest CAS and
    slowest speed in the first used slot to ensure using the least common
    denominator for specs (but I usually make sure all the sticks are
    matched in specs so I don't have to worry about which stick goes in
    which slot). Could be the newer motherboards now use the least common
    denominator of the SPDs across all memory sticks; i.e., if there is a
    mix of CAS-3 and CAS-2 then CAS-3 gets used, and a mix of PC-100 and
    PC-133 will result in a 100MHz clock. The motherboard can't be running
    each slot at a different bus speed and with different delays.

    It is likely that your non-server motherboard uses unbuffered memory
    (http://snipurl.com/5zou and http://snipurl.com/5zoy). Make sure you
    match with what your motherboard supports AND with the type for the
    existing memory sticks that will remain in your system. Because the
    keying for the PCB is different, you can only use one type in all slots.
    The PDF download for the Soyo manual at http://snipurl.com/5zp7 doesn't
    even mention buffered or unbuffered. The Crucial memory selector listed
    unbuffered memory modules for this motherboard (I only looked at a
    couple sizes but the motherboard's memory slots would all be keyed for
    the same type of memory).

    --
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  5. Archived from groups: alt.comp.hardware.homebuilt (More info?)

    99.9 % of the time.... you should not have any problems mixing PC-100
    with PC-133.
    -
  6. Archived from groups: alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

    Motherboards are limited in the memory chip capacity they can address. If I put a 128 MB DIMM with 4 chips in my sister's IBM PC it will recognize it as 64 MB, but if I put in a 128 MB DIMM with 8 chips it will recognize it as 128 MB. Newer DIMMs tend to have higher density chips than older ones and the lack of foresight by the motherboard chipset designers will prevent you from using higher density chips.

    *Vanguard* wrote:
    >
    > > The only thing I would add to the above is the fact that much PC133
    > > memory is high density, and most PC100 is not. What this means is
    > > although the faster speed may work in your computer, your computer may
    > > not recognize the total size of the PC133 stick.
    >
    > Higher density? What do you mean by that? The PC-100 and PC-133 that
    > I've gotten in the past were both DIMMs (chips on both sides of the
    > PCB). They usually look like http://snipurl.com/5znr with the 8 chips
    > on the frontside (9 for ECC) and the controller chips on the backside.
    > The "density" (http://snipurl.com/5zo3) remains the same for, say, a
    > 256MB memory stick whether it is PC-100 or PC-133.

    --
    Mike Walsh
    West Palm Beach, Florida, U.S.A.
  7. Archived from groups: alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

    "Mike Walsh" said in news:408F1635.6B76F52B@sbcglobal.net:
    > Motherboards are limited in the memory chip capacity they can
    > address. If I put a 128 MB DIMM with 4 chips in my sister's IBM PC it
    > will recognize it as 64 MB, but if I put in a 128 MB DIMM with 8
    > chips it will recognize it as 128 MB. Newer DIMMs tend to have higher
    > density chips than older ones and the lack of foresight by the
    > motherboard chipset designers will prevent you from using higher
    > density chips.

    Okay, did a bit more hunting around. Found Kingston has some 4-chip
    modules (never bought Kingston because I've always found another top or
    equivalent brand that was cheaper).

    KVR133X64C3/64
    64MB 8M x 64-Bit PC133
    eight 8M x 8-bit (2M x 8-bit x 4 Bank)

    KVR133X64C2/128
    128MB 16M x 64-Bit PC133
    Four 16M x 16-bit (4M x 16-bit x 4 Bank)

    KVR133X64C2/256
    256MB 32M x 64-Bit PC133
    eight 32M x 8-bit (8M x 8-bit x 4 Bank)

    KVR133X64C2/512
    512MB 64M x 64-Bit PC133
    sixteen 32M x 8-bit (8M x 8-bit x 4 Bank)


    KVR133X64C3/1G
    1GB 128M x 64-Bit PC133
    sixteen 64M x 8-bit (16M x 8-bit x 4 Bank )

    Notice the architecture change for the 128MB module. All the rest are
    8-bit x 4 bank whereas the 128MB module is 16-bit x 4 bank. That module
    might not work in your computer if the controller won't adapt to 2-byte
    wide access from each chip.

    Also, although I have not used low-profile PC-100/133 modules, they do
    exist. There are they types that use the standard sized chips laid out
    horizontally so there are only 4 of them and hence they use the 16-bit x
    4 bank architecture. Some use smaller chips which can still be laid out
    vertically and will have 8 of them on the PCB so they probably use the
    8-bit x 4 bank architecture. The forementioned was for unbuffered
    non-ECC memory. ECC just adds another chip. Registered memory has a
    different architecture and is keyed differently.

    If what Mike refers to as density is what I refer to as architecture (or
    bank schema) then we are in vehement agreement. Unfortunately the
    motherboard manuals rarely mention what schema they will support for the
    memory modules, and the pause when you call their tech support and ask
    about it lets you know they don't know, either.
  8. Archived from groups: alt.comp.hardware.homebuilt (More info?)

    >Higher density? What do you mean by that? The PC-100 and PC-133 that
    >I've gotten in the past were both DIMMs (chips on both sides of the
    >PCB).

    Well my old Emachines can max out at an unofficial 512 meg. Most chips will
    work up to 256 meg total, but with 512 you need two 16 chip (low density) RAM.

    In this case it's a relative density difference between 16 and 8 chip for the
    256 meg module. That is what the other poster was referring to. The textbook
    definition of density is not the focus here, however he used the term
    correctly.

    M.
  9. Archived from groups: alt.comp.hardware.homebuilt (More info?)

    >99.9 % of the time.... you should not have any problems mixing PC-100
    >with PC-133.

    I mix pc 66, 100, and 133, and haven't had an issues on older machines.

    Michael
  10. Archived from groups: alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

    I was using "density" when I should have said chip capacity. I have seen numerous posts about "high density" DIMMs not working properly, but the posters never say exactly what high density is. I guess it is all relative.

    *Vanguard* wrote:
    >
    > Also, although I have not used low-profile PC-100/133 modules, they do
    > exist. There are they types that use the standard sized chips laid out
    > horizontally so there are only 4 of them and hence they use the 16-bit x
    > 4 bank architecture. Some use smaller chips which can still be laid out
    > vertically and will have 8 of them on the PCB so they probably use the
    > 8-bit x 4 bank architecture. The forementioned was for unbuffered
    > non-ECC memory. ECC just adds another chip. Registered memory has a
    > different architecture and is keyed differently.
    >
    > If what Mike refers to as density is what I refer to as architecture (or
    > bank schema) then we are in vehement agreement. Unfortunately the
    > motherboard manuals rarely mention what schema they will support for the
    > memory modules, and the pause when you call their tech support and ask
    > about it lets you know they don't know, either.

    --
    Mike Walsh
    West Palm Beach, Florida, U.S.A.
  11. Archived from groups: alt.comp.hardware.homebuilt (More info?)

    >I was using "density" when I should have said chip capacity. I have seen
    >numerous posts about "high density" DIMMs not working properly, but the
    >posters never say exactly what high density is. I guess it is all relative.

    The reason it's called "high density" is that the individual chips hold more
    than in "low density."

    You could have 8 chips holding 64 units each, or 4 chips holding 128 units
    each. I'm throwing out some random example, but you see the point. Vanguard
    used a real world example.

    I think it's a matter of the way the mobo addresses the higher density modules
    that can be an issue with older mobos.

    Michael
  12. Archived from groups: alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

    "Ablang" <HilaryDuffThePerfectWoman@ablang-duff.com> wrote in
    message news:mpfr80ls4bjfnqhn1dhvpa7sg71lf7rrn7@4ax.com...
    > I looked up the info for my motherboard, a SOYO SY-V6BE+ and it
    says it
    > only takes PC100 RAM (even the online manual says this). Does
    this mean it
    > won't run PC133 RAM, and can I mix 133 & 100 RAM on this board?
    >
    > Who has experience doing this on their boards?

    SOYO SY-V6BE+ -- mo personal knowledge; or any handle on the VIA
    693 chipset.

    I'm gonna be a rotten bastard and tell you to RTFM /and use Google
    ....
  13. Archived from groups: alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

    On Wed, 28 Apr 2004 23:14:21 -0700, "R. Asby Dragon" <ube_never@yahoo.com>
    wrote:

    >
    >"Ablang" <HilaryDuffThePerfectWoman@ablang-duff.com> wrote in
    >message news:mpfr80ls4bjfnqhn1dhvpa7sg71lf7rrn7@4ax.com...
    >> I looked up the info for my motherboard, a SOYO SY-V6BE+ and it
    >says it
    >> only takes PC100 RAM (even the online manual says this). Does
    >this mean it
    >> won't run PC133 RAM, and can I mix 133 & 100 RAM on this board?
    >>
    >> Who has experience doing this on their boards?
    >
    >SOYO SY-V6BE+ -- mo personal knowledge; or any handle on the VIA
    >693 chipset.
    >

    Not much to knowledge about 693 is needed, except for that part about it
    being the last Via chipset that DIDN'T support "high" density memory.
    Typically PC133 memory bought today would have 256Mbit chips, and that
    type can't be used on the OP's board. Since the limitation of the PC100
    memory will apply because of the intention to use both modules, it would
    be easiest to simply buy PC100 memory... these days *almost* all memory
    can run at 133MHz anyway, the primary reason new memory modules are being
    labeled as "PC100" is due to this density compatibility issue with older
    boards/chipsets like the 693. Of course PC100 costs more, but that's a
    given since it takes twice as many chips.
  14. Archived from groups: alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

    You can use 133 but I don't think you can mix them.
    "Ablang" <HilaryDuffThePerfectWoman@ablang-duff.com> wrote in message
    news:mpfr80ls4bjfnqhn1dhvpa7sg71lf7rrn7@4ax.com...
    > I looked up the info for my motherboard, a SOYO SY-V6BE+ and it says it
    > only takes PC100 RAM (even the online manual says this). Does this mean
    it
    > won't run PC133 RAM, and can I mix 133 & 100 RAM on this board?
    >
    > Who has experience doing this on their boards?
  15. Archived from groups: alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

    "ProfGene" <mfevs@winco.net> wrote in message
    news:c6uvnb$90pc$1@news3.infoave.net...
    > You can use 133 but I don't think you can mix them.
    > "Ablang" <HilaryDuffThePerfectWoman@ablang-duff.com> wrote in
    message
    > news:mpfr80ls4bjfnqhn1dhvpa7sg71lf7rrn7@4ax.com...
    > > I looked up the info for my motherboard, a SOYO SY-V6BE+ and it
    says it
    > > only takes PC100 RAM (even the online manual says this). Does
    this mean
    > it
    > > won't run PC133 RAM, and can I mix 133 & 100 RAM on this board?
    > >
    > > Who has experience doing this on their boards?
    >
    >

    They can be mixed. The PC133 RAM will run at the same speed as PC100.
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