So I installed Everest and got the following results for the
Motherboard:
--------[ Motherboard
]-------------------------------------------------------------------------------------------------
Motherboard Properties:
Motherboard ID
62-0821-001131-00101111-040201-SiS746$M848A_M848A RELEASE 08/21/2003
Motherboard Name PCChips M848A
Front Side Bus Properties:
Bus Type DEC Alpha EV6
Bus Width 64-bit
Real Clock 100 MHz (DDR)
Effective Clock 200 MHz
Bandwidth 1600 MB/s
Memory Bus Properties:
Bus Type DDR SDRAM
Bus Width 64-bit
Real Clock 133 MHz (DDR)
Effective Clock 267 MHz
Bandwidth 2133 MB/s
Chipset Bus Properties:
Bus Type SiS MuTIOL
Bus Width 16-bit
Motherboard Physical Info:
CPU Sockets/Slots 1 Socket 462
Expansion Slots 5 PCI, 1 AGP, 1
CNR
RAM Slots 3 DDR DIMM
Integrated Devices Audio, LAN
Form Factor ATX
Motherboard Size 190 mm x 300 mm
Motherboard Chipset SiS748
Motherboard Manufacturer:
Company Name Elitegroup
Computer Systems
Product Information
http://www.pcchips.com.tw/PCCWeb/Products/ProductList.aspx?CategoryID=1&MenuID=16&LanID=0
BIOS Download
http://www.pcchips.com.tw/PCCWeb/Downloads/Category_Download.aspx?Categoryid=1&MenuID=35&LanID=0
and then under the chip set:
--------[ Chipset
]-----------------------------------------------------------------------------------------------------
[ North Bridge: SiS 748 ]
North Bridge Properties:
North Bridge SiS 748
Revision 10
In-Order Queue Depth 7
Memory Timings:
CAS Latency (CL) 2.5T
RAS To CAS Delay (tRCD) 3T
RAS Precharge (tRP) 3T
RAS Active Time (tRAS) 6T
Memory Slots:
DRAM Slot #1 256 MB (DDR
SDRAM)
DRAM Slot #2 512 MB (DDR
SDRAM)
AGP Controller:
AGP Version 2.00
AGP Status Disabled
AGP Device nVIDIA GeForce2
MX/MX400
AGP Aperture Size 128 MB
Supported AGP Speeds 1x, 2x, 4x, 8x
Fast-Write Not Supported
Side Band Addressing Supported,
Disabled
Chipset Manufacturer:
Company Name Silicon
Integrated Systems Corporation
Product Information
http://www.sis.com/products/index.htm#chipsets
Driver Download
http://www.sis.com/download
Problems & Suggestions:
Problem AGP is
disabled. This may cause performance penalty.
There is indeed a reference to Northbridge..
I tried to find the manual from the link but couldn't find my
motherboard there.
Any help really appreciated
David
It is a SIS748 Northbridge, driving three slots.
http://www.sis.com/products/sis748_features.htm
There seem to be no particular restrictions to that chipset, and
the Crucial selector is showing a lot of different sizes of memory
will work.
http://www.crucial.com/store/listparts.aspx?model=M848A
At PC2100 rates, on a chipset rated for PC3200, there really should
not be a problem running three sticks. Even with the bus loading,
it should be easy for the chipset to drive them.
First thing I would recommend, is getting a copy of memtest86+ from
memtest.org . The downloaded program can either format a blank floppy,
and it makes a self-booting test floppy. Or there is an ISO version,
suitable for burning a bootable CD. While the test runs forever, you
only need to run it for two passes (pass counter is on-screen).
I would start with the new 512MB stick by itself. Install it in each
socket in succession and test it. See whether 512MB is reported in
each case. See if it will do even one pass clean. Then you'd know
whether each socket is OK.
The wiping action, of the memory contact against the contact surface
of the DIMM slot, should perform as much cleaning action as is needed.
For example, if the memory module has a gold plating on the contacts,
then applying abrasive cleaning to the contacts, merely removes the
"good" gold, exposing the less noble metal underneath. Gold does not
oxidize, but the underlying metal can.
In terms of sizing the memory, two methods can be used. The SPD chip
on the DIMM, contains timing info, and size info. The BIOS reads the
SPD chip, via the SMBUS serial bus. All three DIMMs would be read,
and timing numbers suitable for the slowest module, are used for
all three.
The BIOS also has the opportunity to test the memory for size. The
BIOS, if they design it that way, can write and read back, "searching"
for the end of memory. Sometimes, the SPD says one thing, and a
"size test" concludes something else. A "size test" might fail, if
one of the write/readback operations fails. That is a potential reason
for memory to be a different size, than as shown in the SPD>
On some chipsets, the memory controller has a limited number of address
bits. Using a memory which needs more address bits than the controller
has, causes only a portion (like half) of a stick to show up. Again,
the size test in the BIOS, may lead to the BIOS reporting only half
the size. That is typically referred to as a "density problem". In the
available info for the SIS748, I see no reason to suspect such a
problem. If you were using 1GB DIMMs (larger than anything you've
currently got), I'd be asking you if the modules had 128Mx4 chips
on them (for example, Nforce2 cannot handle such a chip, according to
reports).
So, there isn't an easy technical explanation for what you've seen so
far. Now, your test procedure, is to determine whether this is a module
problem or a socket problem. You start with one stick, and move
it through all the slots. That proves the contacts in each socket work.
You can repeat with the other two modules, on the off chance that one
of them has a contact problem. The final test, of installing all three,
is the "bus loading" test case, where you are checking to see if the
Northbridge can drive three sticks properly. At PC2100 rates, there
should not be a problem doing that.
Another case to consider, is a "stupid BIOS". You might change the
order of the three sticks in the sockets. Try the 512MB nearest
the processor as one test case. Try the 512MB furthest from the
processor, as a second test case. Some BIOS have been known to
have parsing/setup problems, where they confuse easily. The BIOS
parses the modules in order, and depending on which module it
processes first, the BIOS can reach a different conclusion for
the settings, than if the modules are installed in another order.
Sometimes a BIOS upgrade, if one is available, will change the
symptoms seen.
I presume all three memories are PC2100 and unbuffered memory. As
otherwise, you would not have got a proper report of 512MB with the
2x256MB config, and 512MB reported for the single stick.
So more testing may help identify where the problem is.
Good luck,
Paul
MI:Motherboard or