A8N-sli memory - beware it won't take 4Gb

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

Even though the board claims to support 4Gb of RAM is won't take 4 x
1GB sticks. This seems to be cuased by the ram not being buffered and
hence the board cannot support the power requirements. There is a
compatibility table on the Asus page that shows which dimms are
supported and 4 x 1Gb shows non are supported.

Has anybody managed to get such a setup working i.e. 4Gb of RAM, with
this or any other modern non-server board? I wanted to use all the
memory for running multiple Vmware machines.

Thanks

Ian


--

'What we have here is a failure to communicate'
8 answers Last reply
More about memory beware
  1. Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

    In article <jako31lsof9mmi0s9lnok22ljj6s07ccho@4ax.com>, Blonks
    <Blonkster@_NOSTINKINSPAM_ntlworld.com> wrote:

    > Even though the board claims to support 4Gb of RAM is won't take 4 x
    > 1GB sticks. This seems to be cuased by the ram not being buffered and
    > hence the board cannot support the power requirements. There is a
    > compatibility table on the Asus page that shows which dimms are
    > supported and 4 x 1Gb shows non are supported.
    >
    > Has anybody managed to get such a setup working i.e. 4Gb of RAM, with
    > this or any other modern non-server board? I wanted to use all the
    > memory for running multiple Vmware machines.
    >
    > Thanks
    >
    > Ian

    Maybe you put registered sticks in the board, and the board beeped ?
    It takes unbuffered DIMMs.

    The OP here tried 4x1GB. With two PCI-E video cards, he got 2.25GB
    available, and with one PCI-E video card, he got 2.75GB. This implies
    that the A8N-SLI is just about the worst desktop board you could
    select for a memory hungry application. The lost memory makes
    way for necessary I/O space (PCI-E video cards, PCI-E plugin cards,
    PCI bus cards).

    http://groups.google.ca/groups?threadm=ct2pfu%24m2m%241%40ikaria.belnet.be

    This is an example of a desktop board that claims to support
    8GB.

    "SK8N Specification Summary
    Socket 940 for AMD Opteron processor
    NVIDIA nForce 3 Pro150
    Dual-Channel memory architecture
    Supports PC2700/PC2100/PC1600 ECC DDR SDRAM
    Registered DIMMs
    4 x 184-pin DDR DIMM sockets for up to 8GB memory"

    The SK8N does support memory hoisting, as noted here. If you have
    8GB of memory, what memory hoisting does, is map it as 3GB down
    low, leaves a gap between 3GB and 4GB, then puts the remaining
    5GB above the 4GB mark. So, one chunk of 3GB, one chunk of 5GB,
    and via some mapping, it looks like a contiguous virtual 8GB
    chunk to the system. The hole is then used for the I/O space.
    Apparently, with the right version of BIOS, the SK8N supports
    this function, which tells you support for this was an
    afterthought at Asus.

    http://groups.google.ca/groups?selm=1LoW8-5I9-25%40gated-at.bofh.it

    What is strange, is if I look at the 26094 document at AMD, I
    get the impression that any athlon64/opteron should support
    the memory hoisting function. So, maybe this is purely a
    BIOS limitation, in which case complaining to Asus might
    eventually get it fixed. (Due to AMD's idea of modular
    documentation, when a feature is seen in their documentation,
    you have no way of knowing whether the feature works on
    S754, S939, S940, Opteron etc. Truly a pathetic way to
    document hardware.)

    http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/26094.PDF

    The memory hoisting function is not without side effects. The
    AMD document states that certain memory optimizations are
    disabled, so the memory bandwidth might drop a bit. Also, you
    need OS and application support for this kind of thing, so
    perhaps a server style OS, plus a version of VMware intended to
    run on server type machines, would be required. I don't know
    anything about that stuff.

    Chances are, if a motherboard supports Opteron processors, it
    will do a good job in the memory arena. Unless you can find a
    server motherboard manufacturer that dabbles in desktops, and
    does a good job on all their BIOS.

    Another tidbit:
    http://groups.google.ca/groups?threadm=cmb7sa%24ohu%241%40rena.mat.uc.pt

    I tried downloading a Tyan desktop (S2865) manual, hoping that
    maybe they implement memory hoisting, but the manual is so bad,
    I cannot tell if this function is implemented or not. They have
    an entry called "Bottom of 32-bit[31:24] IO[E0]" and another
    called "S/W memory hole Romapping", and there is zero info on
    what they do.

    Good luck in your quest,

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

    "Blonks" <Blonkster@_NOSTINKINSPAM_ntlworld.com> wrote in message
    news:jako31lsof9mmi0s9lnok22ljj6s07ccho@4ax.com...
    > Even though the board claims to support 4Gb of RAM is won't take 4 x
    > 1GB sticks. This seems to be cuased by the ram not being buffered and
    > hence the board cannot support the power requirements. There is a
    > compatibility table on the Asus page that shows which dimms are
    > supported and 4 x 1Gb shows non are supported.
    >
    > Has anybody managed to get such a setup working i.e. 4Gb of RAM, with
    > this or any other modern non-server board? I wanted to use all the
    > memory for running multiple Vmware machines.
    >
    > Thanks
    >
    > Ian
    >
    >
    > --
    >
    > 'What we have here is a failure to communicate'

    It does. We do it quite a lot.

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

    On Sat, 19 Mar 2005 22:18:43 -0000, "3200+" <nospam@nospam.com> wrote:

    >
    >"Blonks" <Blonkster@_NOSTINKINSPAM_ntlworld.com> wrote in message
    >news:jako31lsof9mmi0s9lnok22ljj6s07ccho@4ax.com...
    >> Even though the board claims to support 4Gb of RAM is won't take 4 x
    >> 1GB sticks. This seems to be cuased by the ram not being buffered and
    >> hence the board cannot support the power requirements. There is a
    >> compatibility table on the Asus page that shows which dimms are
    >> supported and 4 x 1Gb shows non are supported.
    >>
    >> Has anybody managed to get such a setup working i.e. 4Gb of RAM, with
    >> this or any other modern non-server board? I wanted to use all the
    >> memory for running multiple Vmware machines.
    >>
    >> Thanks
    >>
    >> Ian
    >>
    >>
    >> --
    >>
    >> 'What we have here is a failure to communicate'
    >
    >It does. We do it quite a lot.
    >
    >Jon
    >
    Thats good news - can you tell me what ram you used as I tried 4 x
    Crucial ballistix pc400?

    TIA

    Ian


    --

    'What we have here is a failure to communicate'
  4. Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

    have you tried xp 64bit?


    "Paul" <nospam@needed.com> wrote in message
    news:nospam-1903051922190001@192.168.1.178...
    > In article <jako31lsof9mmi0s9lnok22ljj6s07ccho@4ax.com>, Blonks
    > <Blonkster@_NOSTINKINSPAM_ntlworld.com> wrote:
    >
    >> Even though the board claims to support 4Gb of RAM is won't take 4 x
    >> 1GB sticks. This seems to be cuased by the ram not being buffered and
    >> hence the board cannot support the power requirements. There is a
    >> compatibility table on the Asus page that shows which dimms are
    >> supported and 4 x 1Gb shows non are supported.
    >>
    >> Has anybody managed to get such a setup working i.e. 4Gb of RAM, with
    >> this or any other modern non-server board? I wanted to use all the
    >> memory for running multiple Vmware machines.
    >>
    >> Thanks
    >>
    >> Ian
    >
    > Maybe you put registered sticks in the board, and the board beeped ?
    > It takes unbuffered DIMMs.
    >
    > The OP here tried 4x1GB. With two PCI-E video cards, he got 2.25GB
    > available, and with one PCI-E video card, he got 2.75GB. This implies
    > that the A8N-SLI is just about the worst desktop board you could
    > select for a memory hungry application. The lost memory makes
    > way for necessary I/O space (PCI-E video cards, PCI-E plugin cards,
    > PCI bus cards).
    >
    > http://groups.google.ca/groups?threadm=ct2pfu%24m2m%241%40ikaria.belnet.be
    >
    > This is an example of a desktop board that claims to support
    > 8GB.
    >
    > "SK8N Specification Summary
    > Socket 940 for AMD Opteron processor
    > NVIDIA nForce 3 Pro150
    > Dual-Channel memory architecture
    > Supports PC2700/PC2100/PC1600 ECC DDR SDRAM
    > Registered DIMMs
    > 4 x 184-pin DDR DIMM sockets for up to 8GB memory"
    >
    > The SK8N does support memory hoisting, as noted here. If you have
    > 8GB of memory, what memory hoisting does, is map it as 3GB down
    > low, leaves a gap between 3GB and 4GB, then puts the remaining
    > 5GB above the 4GB mark. So, one chunk of 3GB, one chunk of 5GB,
    > and via some mapping, it looks like a contiguous virtual 8GB
    > chunk to the system. The hole is then used for the I/O space.
    > Apparently, with the right version of BIOS, the SK8N supports
    > this function, which tells you support for this was an
    > afterthought at Asus.
    >
    > http://groups.google.ca/groups?selm=1LoW8-5I9-25%40gated-at.bofh.it
    >
    > What is strange, is if I look at the 26094 document at AMD, I
    > get the impression that any athlon64/opteron should support
    > the memory hoisting function. So, maybe this is purely a
    > BIOS limitation, in which case complaining to Asus might
    > eventually get it fixed. (Due to AMD's idea of modular
    > documentation, when a feature is seen in their documentation,
    > you have no way of knowing whether the feature works on
    > S754, S939, S940, Opteron etc. Truly a pathetic way to
    > document hardware.)
    >
    > http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/26094.PDF
    >
    > The memory hoisting function is not without side effects. The
    > AMD document states that certain memory optimizations are
    > disabled, so the memory bandwidth might drop a bit. Also, you
    > need OS and application support for this kind of thing, so
    > perhaps a server style OS, plus a version of VMware intended to
    > run on server type machines, would be required. I don't know
    > anything about that stuff.
    >
    > Chances are, if a motherboard supports Opteron processors, it
    > will do a good job in the memory arena. Unless you can find a
    > server motherboard manufacturer that dabbles in desktops, and
    > does a good job on all their BIOS.
    >
    > Another tidbit:
    > http://groups.google.ca/groups?threadm=cmb7sa%24ohu%241%40rena.mat.uc.pt
    >
    > I tried downloading a Tyan desktop (S2865) manual, hoping that
    > maybe they implement memory hoisting, but the manual is so bad,
    > I cannot tell if this function is implemented or not. They have
    > an entry called "Bottom of 32-bit[31:24] IO[E0]" and another
    > called "S/W memory hole Romapping", and there is zero info on
    > what they do.
    >
    > Good luck in your quest,
    >
    > Paul
  5. Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

    Blonks wrote:
    > Even though the board claims to support 4Gb of RAM is won't take 4 x
    > 1GB sticks. This seems to be cuased by the ram not being buffered and
    > hence the board cannot support the power requirements. There is a
    > compatibility table on the Asus page that shows which dimms are
    > supported and 4 x 1Gb shows non are supported.
    >
    > Has anybody managed to get such a setup working i.e. 4Gb of RAM, with
    > this or any other modern non-server board? I wanted to use all the
    > memory for running multiple Vmware machines.

    The A8N-sli likely supports 4GB with bios 1006, from the bios changelog
    "5.Add Memory Re-map function SETUP Item", this should do the trick.
    What has been said about needing an OS which supports this is still true
    though - windows xp professional (32bit) won't this support at all, even
    with PAE the address range is limited to 2^32 - thus the remapped memory
    is out of reach of the OS. Windows XP Server (standard edition) also
    "only" supports 4GB of ram, but this time for real, i.e. does not limit
    the address range to 2^32, thus you will get the full 4GB. With even
    more memory (I'm not 100% certain, but believe the socket 939 boards
    should actually be able to take 4 2GB dimms, though these would need to
    be built with 16 (unbuffered) 1gbit chips, and I've not yet seen such
    memory modules, I have no idea if they will ever appear in the market as
    memory manufacturers are unlikely to invest in ddr1 memory manufacturing
    at this point) you'd need the advanced server or enterprise edition.
    Or use linux or windows xp 64bit...

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

    In article <3a6fj4F64kkrjU1@individual.net>, Roland Scheidegger
    <rscheidegger@gmx.ch> wrote:

    > Blonks wrote:
    > > Even though the board claims to support 4Gb of RAM is won't take 4 x
    > > 1GB sticks. This seems to be cuased by the ram not being buffered and
    > > hence the board cannot support the power requirements. There is a
    > > compatibility table on the Asus page that shows which dimms are
    > > supported and 4 x 1Gb shows non are supported.
    > >
    > > Has anybody managed to get such a setup working i.e. 4Gb of RAM, with
    > > this or any other modern non-server board? I wanted to use all the
    > > memory for running multiple Vmware machines.
    >
    > The A8N-sli likely supports 4GB with bios 1006, from the bios changelog
    > "5.Add Memory Re-map function SETUP Item", this should do the trick.
    > What has been said about needing an OS which supports this is still true
    > though - windows xp professional (32bit) won't this support at all, even
    > with PAE the address range is limited to 2^32 - thus the remapped memory
    > is out of reach of the OS. Windows XP Server (standard edition) also
    > "only" supports 4GB of ram, but this time for real, i.e. does not limit
    > the address range to 2^32, thus you will get the full 4GB. With even
    > more memory (I'm not 100% certain, but believe the socket 939 boards
    > should actually be able to take 4 2GB dimms, though these would need to
    > be built with 16 (unbuffered) 1gbit chips, and I've not yet seen such
    > memory modules, I have no idea if they will ever appear in the market as
    > memory manufacturers are unlikely to invest in ddr1 memory manufacturing
    > at this point) you'd need the advanced server or enterprise edition.
    > Or use linux or windows xp 64bit...
    >
    > Roland

    There are some 2GB unbuffered modules at the top of this page,
    but they are only DDR333.

    http://www.samsung.com/Products/Semiconductor/common/product_list.aspx?family_cd=DRM030202

    The PC2100 version is even on the AMD Athlon64 qualified memory
    list (near the bottom of the doc):

    http://www.amd.com/us-en/assets/content_type/DownloadableAssets/Athlon_64_Unbuffered_DIMM_AVL.pdf

    I cannot find any for sale though.

    Fun times ahead :-)

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

    Paul wrote:
    >
    > There are some 2GB unbuffered modules at the top of this page,
    > but they are only DDR333.
    >
    > http://www.samsung.com/Products/Semiconductor/common/product_list.aspx?family_cd=DRM030202
    >
    > The PC2100 version is even on the AMD Athlon64 qualified memory
    > list (near the bottom of the doc):
    >
    > http://www.amd.com/us-en/assets/content_type/DownloadableAssets/Athlon_64_Unbuffered_DIMM_AVL.pdf
    >
    > I cannot find any for sale though.
    >
    > Fun times ahead :-)
    Indeed. These modules use multi-die memory chips though. Maybe that's
    the reason they can't reach DDR-400 speed (?), and I doubt pricing is
    ever going to be mass-market compatible with such devices.

    Roland
    btw forgot to add previously, just because a board has the memory remap
    option doesn't mean it's actually going to work in all OS, that's
    especially true for Asus which have a habit implementing some things not
    quite spec-compliant. The remapping was known to be broken on the SK8N,
    it happened to work with some luck on W2k3 server, but didn't in linux
    and may very well not have worked in w2k xp64 neither. No idea if asus
    have fixed that and are implementing it how they should now in the a8n...
  8. Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

    In article <3a8o3aF6ahtviU1@individual.net>, Roland Scheidegger
    <rscheidegger@gmx.ch> wrote:

    > Paul wrote:
    > >
    > > There are some 2GB unbuffered modules at the top of this page,
    > > but they are only DDR333.
    > >
    > >
    http://www.samsung.com/Products/Semiconductor/common/product_list.aspx?family_cd=DRM030202
    > >
    > > The PC2100 version is even on the AMD Athlon64 qualified memory
    > > list (near the bottom of the doc):
    > >
    > >
    http://www.amd.com/us-en/assets/content_type/DownloadableAssets/Athlon_64_Unbuffered_DIMM_AVL.pdf
    > >
    > > I cannot find any for sale though.
    > >
    > > Fun times ahead :-)
    > Indeed. These modules use multi-die memory chips though. Maybe that's
    > the reason they can't reach DDR-400 speed (?), and I doubt pricing is
    > ever going to be mass-market compatible with such devices.
    >
    > Roland
    > btw forgot to add previously, just because a board has the memory remap
    > option doesn't mean it's actually going to work in all OS, that's
    > especially true for Asus which have a habit implementing some things not
    > quite spec-compliant. The remapping was known to be broken on the SK8N,
    > it happened to work with some luck on W2k3 server, but didn't in linux
    > and may very well not have worked in w2k xp64 neither. No idea if asus
    > have fixed that and are implementing it how they should now in the a8n...

    On the Samsung web page, it says the module uses 128Mx8 chips.
    i don't think they are stacked. When I compared the input
    capacitance on some 1GB and some 2GB modules, they are the
    same. It is academic anyway - Micron had some 4GB modules for
    $6000 or $7000, so I doubt anyone would be able to afford a module
    like that. Still, it is fun to dream...

    Paul
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