A7N8X Deluxe 1.04 & Mobile 2500+ how to set the voltage to..

Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

Greetz ppl! I'm trying to lower the voltage so my cpu would be set to
default 1.45, just to reduce the temp. I don't want to overclock, I just
want to set the system running so kool it wouldn't need a rear case fan. But
this board doesn't seem to allow voltages lower than 1.575, and that is 8%
higher than Mobile needs. I got the latest 1009 beta bios. I've read the
thread on "options for undervolting", but the 8RDAVcore seems only to
support the A7N8X 2.0 version. Any ideas? Tweaked BIOS? No "wire mods"
please!

Thanx in advance!
6 answers Last reply
More about a7n8x deluxe mobile 2500 voltage
  1. Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

    thats as low as it goes i believe
    even with the newest a7n8x mobos aswell

    "Drummer@Home" <spamoff!drummer@mail.inet.hr> wrote in message
    news:d9uthv$smu$1@ss405.t-com.hr...
    > Greetz ppl! I'm trying to lower the voltage so my cpu would be set to
    > default 1.45, just to reduce the temp. I don't want to overclock, I just
    > want to set the system running so kool it wouldn't need a rear case fan.
    > But this board doesn't seem to allow voltages lower than 1.575, and that
    > is 8% higher than Mobile needs. I got the latest 1009 beta bios. I've read
    > the thread on "options for undervolting", but the 8RDAVcore seems only to
    > support the A7N8X 2.0 version. Any ideas? Tweaked BIOS? No "wire mods"
    > please!
    >
    > Thanx in advance!
    >
  2. Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

    "Drummer@Home" <spamoff!drummer@mail.inet.hr> wrote in message
    news:d9uthv$smu$1@ss405.t-com.hr...
    > Greetz ppl! I'm trying to lower the voltage so my cpu would be set to
    > default 1.45, just to reduce the temp. I don't want to overclock, I just
    > want to set the system running so kool it wouldn't need a rear case fan.
    > But this board doesn't seem to allow voltages lower than 1.575, and that
    > is 8% higher than Mobile needs. I got the latest 1009 beta bios. I've read
    > the thread on "options for undervolting", but the 8RDAVcore seems only to
    > support the A7N8X 2.0 version. Any ideas? Tweaked BIOS? No "wire mods"
    > please!

    I've looked at doing this for some time on an A7N8X del. 2.0, and I've
    come to the conclusion that it's not possible to undervolt Vcore on this
    mobo, whatever revision/version.
    I've not even seen any 'wire mods' (anyone know of one?)
    I'm not really complaining though as I bought it for overclocking, and
    ran an XP2500 as a 3200 for a couple of years, so.. :)
    --
    Rob
  3. Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

    In article <d9uthv$smu$1@ss405.t-com.hr>, "Drummer@Home"
    <spamoff!drummer@mail.inet.hr> wrote:

    > Greetz ppl! I'm trying to lower the voltage so my cpu would be set to
    > default 1.45, just to reduce the temp. I don't want to overclock, I just
    > want to set the system running so kool it wouldn't need a rear case fan. But
    > this board doesn't seem to allow voltages lower than 1.575, and that is 8%
    > higher than Mobile needs. I got the latest 1009 beta bios. I've read the
    > thread on "options for undervolting", but the 8RDAVcore seems only to
    > support the A7N8X 2.0 version. Any ideas? Tweaked BIOS? No "wire mods"
    > please!
    >
    > Thanx in advance!

    I haven't seen Vcore mods listed as a change to hacked BIOS,
    so I don't think you will find the capability there. There are
    a few BIOS out there, but it takes a good deal of searching to
    track down Trats or the Uber BIOS, as a couple of examples.

    The author of 8RDAVcore probably took advantage of the downloadable
    datasheets for some of the Attansic asics. Attansic is a fabless
    chip company, down the street from Asus. I believe Asus invested some
    money in them (just like Ralinktech). Some of the Attansic products
    are made just for Asus, or at least the chip datasheets are not listed
    on the Attansic web page.

    Attansic makes some "overclock controllers". These are basically
    chips that sit on the SMBUS (the same bus that reads the SPD EEPROM
    on your DIMMs), and they offer a bunch of GPIO (general purpose I/O)
    pins, as well as a watchdog timer. Depending on the chip used on
    your board, these GPIO connect to the FID and VID signals, in the
    same way that a "wire mod" would. I presume at power up, that the
    CPU defaults are used, until the BIOS code runs, and then commands
    can be sent down the SMBUS to the overclock controller. The
    watchdog timer could be used to detect a crash, but it is hard
    to say whether it is used or not (nasty side effects if the timer
    triggers when you least expect it).

    Why is this important ? If the author of 8RDAVcore had a datasheet
    for the chip on your motherboard, _and_ the chip had the VID pins on
    it for changing Vcore, then a version could be made for your board.
    While the Attansic web page has datasheets for the ATXP1, ATXP3, and
    ATXP5, I don't see data for the ATXP2. If your board uses that chip,
    it may be difficult to make a utility to do the job.

    You could always use a wire mod :-(

    NVSU (Nvidia System Utility) would be another option, but I think
    that only works for A7N8X-E (and the voltage only goes down to the
    1.4V or so range anyway - it apparently doesn't go all the way
    to 1.1V). If all of this bothers you terribly, there are apparently
    DFI boards, and perhaps Abit boards, that allow undervolting from
    the BIOS menu. You might investigate some of those boards as options
    as well.

    In your quest for a quiet PC, don't forget your poor disk drives.
    They need cooling air a lot more than any processor, and eliminating
    all case fans might cause their case temp to go too high. I would
    eliminate all fans except any fan you have arranged to keep your
    hard drives cool. Or, investigate devices like this:

    http://www.zalman.co.kr/eng/product/code_list.asp?code=019

    Also, another platform to consider, is a 855GME based board with
    a low end Pentium-M on it (the low end being suggested to keep the
    price of the CPU within reason - about $200 or so). If you use
    a motherboard that supports all the features that are in a laptop,
    that might make a good starting point for a fanless machine. Perhaps
    any hard drives could be placed in (fan equipped) enclosures that
    are remoted from the PC. That will isolate their noise from you.

    By the way, CMOS power dissipation is proportional to FCV**2,
    so a 1.08 voltage factor means there is roughly 1.08*1.08 ==> 16.6%
    more heat than is necessary. Keep that in mind when pricing out
    options for your XP-M. If it was 16.6% cooler, would that be
    enough ?

    Paul
  4. Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

    "Paul" <nospam@needed.com> wrote in message
    news:nospam-3006050505320001@192.168.1.178...

    > You could always use a wire mod :-(

    Well, that's the last option on the list...

    > NVSU (Nvidia System Utility) would be another option, but I think

    Haven't tried yet!

    > that only works for A7N8X-E (and the voltage only goes down to the
    > 1.4V or so range anyway - it apparently doesn't go all the way
    > to 1.1V). If all of this bothers you terribly, there are apparently
    > DFI boards, and perhaps Abit boards, that allow undervolting from
    > the BIOS menu. You might investigate some of those boards as options
    > as well.

    aaargh changing the motherboard? selling this one and buying another...
    again, pain in the ... but I might consider it.

    > In your quest for a quiet PC, don't forget your poor disk drives.
    > They need cooling air a lot more than any processor, and eliminating
    > all case fans might cause their case temp to go too high. I would
    > eliminate all fans except any fan you have arranged to keep your
    > hard drives cool. Or, investigate devices like this:

    OK, I might consider that.

    > By the way, CMOS power dissipation is proportional to FCV**2,
    > so a 1.08 voltage factor means there is roughly 1.08*1.08 ==> 16.6%
    > more heat than is necessary. Keep that in mind when pricing out
    > options for your XP-M. If it was 16.6% cooler, would that be
    > enough ?

    Well, 51°C -16.6% = 43°C That would be just fine.

    Thanx for the exeptionaly well detailed list of solutions! If you ever come
    to Croatia, drop by :-)
  5. Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

    In article <da1vid$bsn$1$8302bc10@news.demon.co.uk>, "Oldish sod"
    <SpamDiddlyDooDoo@noway.nowhere.con> wrote:

    > "Drummer@Home" <spamoff!drummer@mail.inet.hr> wrote in message
    > news:d9uthv$smu$1@ss405.t-com.hr...
    > > Greetz ppl! I'm trying to lower the voltage so my cpu would be set to
    > > default 1.45, just to reduce the temp. I don't want to overclock, I just
    > > want to set the system running so kool it wouldn't need a rear case fan.
    > > But this board doesn't seem to allow voltages lower than 1.575, and that
    > > is 8% higher than Mobile needs. I got the latest 1009 beta bios. I've read
    > > the thread on "options for undervolting", but the 8RDAVcore seems only to
    > > support the A7N8X 2.0 version. Any ideas? Tweaked BIOS? No "wire mods"
    > > please!
    >
    > I've looked at doing this for some time on an A7N8X del. 2.0, and I've
    > come to the conclusion that it's not possible to undervolt Vcore on this
    > mobo, whatever revision/version.
    > I've not even seen any 'wire mods' (anyone know of one?)
    > I'm not really complaining though as I bought it for overclocking, and
    > ran an XP2500 as a 3200 for a couple of years, so.. :)

    There is another tool that can change VID setting. It is called
    CPUMSR, but it doesn't seem to work with Nforce2 boards. The
    board will freeze if you try to change the voltage (and the
    processor used, must be a XP-M mobile, or be an ordinary chip
    modded to become a mobile, to work with CPUMSR). I'm not at all
    certain how this is supposed to work at the hardware level, as
    the description on the CPUMSR web page suggests there are "softVID"
    pins as well as the ordinary VID pins on a Mobile processor.
    Since I cannot download a Mobile datasheet, this is hard to
    verify.

    This page shows the wire mods graphically:

    http://www.ocinside.de/go_e.html?/html/workshop/pinmod/amd_pinmod.html

    If you select "Socket view", and set Vcore to "1.85 volts",
    you'll see an example of what area of the processor socket
    gets the wires added.

    PDF page 66 of this document, shows the five VID socket holes on
    the left hand side (see the pins on row "L"). Connecting a pin to
    VCC is a logic "1" and alternately connecting to VSS is a logic "0".
    You'll notice that VID4 has easy access to VSS, but not VCC, so
    forcing a logic "1" on there could be a bit dangerous, if a long
    bare wire is required. That would be a PITA if you need to set VID4
    to logic 1. Insulating the wire could cause the processor to not
    sit flat, causing poor CPU cooling.

    http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/26237.PDF

    In the same document, the "desktop" voltage table is shown on
    PDF pg.90.

    If you are using an AthlonXP-M processor, the VID voltage table for
    that can be found on fab51:

    http://fab51.com/cpu/barton/athlon-e23.html#L11

    The L11 table shows the correspondence between mobile and desktop
    processors. My "Q" for example, would draw 1.450V if inserted in
    a mobile motherboard, and instead it shows as 1.575V on my A7N8X-E.
    That means VID4..VID0 values are 01011, as page 90 of the 26237.PDF
    document shows 1.575V being 01011 binary value.

    Looking at the table, the nearest convenient voltage value with
    respect to 1.575V (01011) would be 1.475V (01111). I picked that
    case because only one piece of wire would be needed to change
    VID2 from logic "0" to logic "1". A wire inserted in socket hole
    "L5" joined to "M4", would connect VID2 to VCC ("1"). The BIOS
    Vcore setting _must_ be set to "Auto" when you do a wire mod,
    as you do not want the BIOS fighting with the electrical short
    caused by the wire. If you select a non-Auto Vcore value in
    the BIOS, there have to be some GPIO pins somewhere that are being
    used to drive the VID pins, and you have no way of knowing
    exactly how Asus is doing it. A selection of "Auto" _should_
    cause the BIOS to tristate the GPIO pins, so there is no
    contention between wires and GPIOs.

    Another thing to consider, is the electrical spec of the processor
    itself. A careful experimenter will also want to check that the
    wires will not damage the processor.

    Table 10. VID[4:0] DC Characteristics
    Parameter Description Min Max
    IOL Output Current Low 6 mA ---
    VOH Output High Voltage ­ 5.25 V *

    What this means is, when the processor VID pin makes a "0",
    it can sink up to 6 milliamps without damage. Connecting a wire
    to VCC (1.5 volts) to force a "1", pumps current into that
    signal, potentially violating the spec. If the VID pin is
    trying to make a "1", it is effectively an open circuit, and
    a voltage of up to 5.25 volts can be applied to it. (The Vcore
    regulator has pullup resistors connected to some voltage, and
    that is the purpose of specifying the 5.25 volts, so if the
    Vcore regulator connects its pullup resistors to +5V, there
    won't be breakdown damage to the VID pins.)

    What does this say about our proposed VID2 wire mod above ?
    It says we could potentially damage the VID2 signal, but I suppose
    people do this all the time. I would say according to the Athlon
    spec, forcing VID signals to "0" is safe, while forcing them
    to "1" we really cannot be sure what will happen to the processor
    in the long term. (There is no way to know whether the processor
    VID pin is simply a bond wire to ground inside the package, or
    is an open drain transistor connected to a lasered fuse - to assess
    the situation properly, you would want to do an I versus V curve
    for the pin, to get some idea of what structure drives it inside
    the package).

    To answer this question, we can consult a venerable source:

    http://web.archive.org/web/20040412055223/www.beachlink.com/candjac/slotAocg.htm
    http://web.archive.org/web/20031208175846/www.beachlink.com/candjac/gfds.htm

    The claim here is, that resistors are being used by the processor
    for setting VID. This means you can use VCC or VSS to program
    the value on a VID pin, with less to worry about. My worry was
    that these pins were driven by transistors. The Athlon Model10
    datasheet mentions "strapped" (which informally means resistors
    in engineering-speak), and if you believe the info on PDF page
    50 of the datasheet, the resistors inside the processor are
    150 ohms (whereas the candjac site states they are 100 ohms).

    The candjac "gfds.htm" page mentions another issue, and that is
    whether a wire mod of a VID pin to VCC, gives enough voltage
    to make a valid logic "1". According to my notes, the A7N8X
    uses a L6917B voltage regulator (a 28 pin chip to the left of
    the processor socket). The datasheet for that part says the
    VID pins are "TTL compatible", which, one would hope, means
    anything more than 0.8V would give a logic 1. Since the wire
    mod is actually using the Vcore voltage to make the logic 1,
    the lower you set Vcore, the less adequate the logic 1 becomes,
    that you are sending to the VID pins on the L6917B. Since
    Vcore won't be set lower than about 1.3V or so, this shouldn't
    be a problem (and you'll be able to see in Asus Probe, whether
    the wire mod is working anyway).

    So, it looks like the wire mod should work OK :-)

    Why did I go through all this ? To show that wire modding is
    not a trivial art :-) There are some Intel processors, where
    this same technique would not be appropriate, so the ideas
    don't necessarily transfer to other situations. A good mod
    should be reversible and not leave traces of what you've
    done :-)

    Paul
  6. Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

    "Paul" <nospam@needed.com> wrote in message
    news:nospam-0107051313070001@192.168.1.178...
    > In article <da1vid$bsn$1$8302bc10@news.demon.co.uk>, "Oldish sod"
    > <SpamDiddlyDooDoo@noway.nowhere.con> wrote:
    >
    >> "Drummer@Home" <spamoff!drummer@mail.inet.hr> wrote in message
    >> news:d9uthv$smu$1@ss405.t-com.hr...
    >> > Greetz ppl! I'm trying to lower the voltage so my cpu would be set to
    >> > default 1.45, just to reduce the temp. I don't want to overclock, I
    >> > just
    >> > want to set the system running so kool it wouldn't need a rear case
    >> > fan.
    >> > But this board doesn't seem to allow voltages lower than 1.575, and
    >> > that
    >> > is 8% higher than Mobile needs. I got the latest 1009 beta bios. I've
    >> > read
    >> > the thread on "options for undervolting", but the 8RDAVcore seems only
    >> > to
    >> > support the A7N8X 2.0 version. Any ideas? Tweaked BIOS? No "wire mods"
    >> > please!
    >>
    >> I've looked at doing this for some time on an A7N8X del. 2.0, and I've
    >> come to the conclusion that it's not possible to undervolt Vcore on this
    >> mobo, whatever revision/version.
    >> I've not even seen any 'wire mods' (anyone know of one?)
    >> I'm not really complaining though as I bought it for overclocking, and
    >> ran an XP2500 as a 3200 for a couple of years, so.. :)
    >
    > There is another tool that can change VID setting. It is called
    > CPUMSR, but it doesn't seem to work with Nforce2 boards. The
    > board will freeze if you try to change the voltage (and the
    > processor used, must be a XP-M mobile, or be an ordinary chip
    > modded to become a mobile, to work with CPUMSR). I'm not at all
    > certain how this is supposed to work at the hardware level, as
    > the description on the CPUMSR web page suggests there are "softVID"
    > pins as well as the ordinary VID pins on a Mobile processor.
    > Since I cannot download a Mobile datasheet, this is hard to
    > verify.
    >
    > This page shows the wire mods graphically:
    >
    > http://www.ocinside.de/go_e.html?/html/workshop/pinmod/amd_pinmod.html
    >
    > If you select "Socket view", and set Vcore to "1.85 volts",
    > you'll see an example of what area of the processor socket
    > gets the wires added.
    >
    > PDF page 66 of this document, shows the five VID socket holes on
    > the left hand side (see the pins on row "L"). Connecting a pin to
    > VCC is a logic "1" and alternately connecting to VSS is a logic "0".
    > You'll notice that VID4 has easy access to VSS, but not VCC, so
    > forcing a logic "1" on there could be a bit dangerous, if a long
    > bare wire is required. That would be a PITA if you need to set VID4
    > to logic 1. Insulating the wire could cause the processor to not
    > sit flat, causing poor CPU cooling.
    >
    > http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/26237.PDF
    >
    > In the same document, the "desktop" voltage table is shown on
    > PDF pg.90.
    >
    > If you are using an AthlonXP-M processor, the VID voltage table for
    > that can be found on fab51:
    >
    > http://fab51.com/cpu/barton/athlon-e23.html#L11
    >
    > The L11 table shows the correspondence between mobile and desktop
    > processors. My "Q" for example, would draw 1.450V if inserted in
    > a mobile motherboard, and instead it shows as 1.575V on my A7N8X-E.
    > That means VID4..VID0 values are 01011, as page 90 of the 26237.PDF
    > document shows 1.575V being 01011 binary value.
    >
    > Looking at the table, the nearest convenient voltage value with
    > respect to 1.575V (01011) would be 1.475V (01111). I picked that
    > case because only one piece of wire would be needed to change
    > VID2 from logic "0" to logic "1". A wire inserted in socket hole
    > "L5" joined to "M4", would connect VID2 to VCC ("1"). The BIOS
    > Vcore setting _must_ be set to "Auto" when you do a wire mod,
    > as you do not want the BIOS fighting with the electrical short
    > caused by the wire. If you select a non-Auto Vcore value in
    > the BIOS, there have to be some GPIO pins somewhere that are being
    > used to drive the VID pins, and you have no way of knowing
    > exactly how Asus is doing it. A selection of "Auto" _should_
    > cause the BIOS to tristate the GPIO pins, so there is no
    > contention between wires and GPIOs.
    >
    > Another thing to consider, is the electrical spec of the processor
    > itself. A careful experimenter will also want to check that the
    > wires will not damage the processor.
    >
    > Table 10. VID[4:0] DC Characteristics
    > Parameter Description Min Max
    > IOL Output Current Low 6 mA ---
    > VOH Output High Voltage ­ 5.25 V *
    >
    > What this means is, when the processor VID pin makes a "0",
    > it can sink up to 6 milliamps without damage. Connecting a wire
    > to VCC (1.5 volts) to force a "1", pumps current into that
    > signal, potentially violating the spec. If the VID pin is
    > trying to make a "1", it is effectively an open circuit, and
    > a voltage of up to 5.25 volts can be applied to it. (The Vcore
    > regulator has pullup resistors connected to some voltage, and
    > that is the purpose of specifying the 5.25 volts, so if the
    > Vcore regulator connects its pullup resistors to +5V, there
    > won't be breakdown damage to the VID pins.)
    >
    > What does this say about our proposed VID2 wire mod above ?
    > It says we could potentially damage the VID2 signal, but I suppose
    > people do this all the time. I would say according to the Athlon
    > spec, forcing VID signals to "0" is safe, while forcing them
    > to "1" we really cannot be sure what will happen to the processor
    > in the long term. (There is no way to know whether the processor
    > VID pin is simply a bond wire to ground inside the package, or
    > is an open drain transistor connected to a lasered fuse - to assess
    > the situation properly, you would want to do an I versus V curve
    > for the pin, to get some idea of what structure drives it inside
    > the package).
    >
    > To answer this question, we can consult a venerable source:
    >
    > http://web.archive.org/web/20040412055223/www.beachlink.com/candjac/slotAocg.htm
    > http://web.archive.org/web/20031208175846/www.beachlink.com/candjac/gfds.htm
    >
    > The claim here is, that resistors are being used by the processor
    > for setting VID. This means you can use VCC or VSS to program
    > the value on a VID pin, with less to worry about. My worry was
    > that these pins were driven by transistors. The Athlon Model10
    > datasheet mentions "strapped" (which informally means resistors
    > in engineering-speak), and if you believe the info on PDF page
    > 50 of the datasheet, the resistors inside the processor are
    > 150 ohms (whereas the candjac site states they are 100 ohms).
    >
    > The candjac "gfds.htm" page mentions another issue, and that is
    > whether a wire mod of a VID pin to VCC, gives enough voltage
    > to make a valid logic "1". According to my notes, the A7N8X
    > uses a L6917B voltage regulator (a 28 pin chip to the left of
    > the processor socket). The datasheet for that part says the
    > VID pins are "TTL compatible", which, one would hope, means
    > anything more than 0.8V would give a logic 1. Since the wire
    > mod is actually using the Vcore voltage to make the logic 1,
    > the lower you set Vcore, the less adequate the logic 1 becomes,
    > that you are sending to the VID pins on the L6917B. Since
    > Vcore won't be set lower than about 1.3V or so, this shouldn't
    > be a problem (and you'll be able to see in Asus Probe, whether
    > the wire mod is working anyway).
    >
    > So, it looks like the wire mod should work OK :-)
    >
    > Why did I go through all this ? To show that wire modding is
    > not a trivial art :-) There are some Intel processors, where
    > this same technique would not be appropriate, so the ideas
    > don't necessarily transfer to other situations. A good mod
    > should be reversible and not leave traces of what you've
    > done :-)

    Now that's what I call a comprehensive answer. Many
    thanks, Paul! 'Will have to re-re-read, though.. :)
    OT, this kind of stuff reminds me of a calculator (Casio,
    FX-something, I think) many, many moons ago when at
    'college' - it cost 12 'units', but the guy next to me paid
    3 times as much for his, as it had polar/rectangular
    coordinate conversion buttons. Turned-out he paid
    3 times as much for a bit of extra 'silk-screen' printing
    on the keypad (confirmed when tried on mine).
    This'll be a little trickier! :)
    Regards,
    --
    Rob
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