Andi Kleen wrote:
On Mon, Jan 24, 2005 at 11:18:00AM -0500, Ken Siersma wrote:
Andi Kleen wrote:
so I'm not sure which kernel you are actually running). I set my Adjust Memory option in the BIOS to Auto, put in the other 2 GB of RAM, and
That's the problem. This option doesn't seem to work reliably on the Tyan boards. Turn it off.
-Andi
Ah, but that seemed to be the only way according to Kevin Gassiot to get all 4 GB of my RAM to show up. Without it, I get only 3264 MB or so - varies depending on the AGP Aperture.
Yeah, there is no way around it to the best of my knowledge (unless Tyan fixes their BIOS to make the system not instable with memory hoisting)
-Andi
I sent a message out to techsupport@tyan.com concerning this issue, and received a reply back that included a FAQ for the Thunder K8W. Two of the FAQs discussed this issue: First one: "Why does my OS see less than the total memory installed when I install 4GB or more of memory (typically 512MB less) The BIOS needs to overlay the APIC, ACPI Table, AGP Aperture and PCI MMIO (Memory-mapped I/O [see PCI Spec 2.3, Section 3.2.2 for more information]) over the last 512MB of the 4GB physical address space. OS accessible memoryand these structures cannot both exist at the same place and this portion of DRAM is hidden and unavailable to the OS." And the second one: "Is there a solution for the missing memory when using 4GB of total memory? Not easily, the theoretical possibility exists that the BIOS can map all of the addresses attached to one DIMM module above the 4GB limit, but the BIOS cannot move smaller address ranges piece by piece. Mapping a whole DIMM is a new concept, unproven in real world testing. It also penalizes 32-bit OS's that cannot use more than 4GB. Since the BIOS does not know what OS you have when it does the memory assignments, it has to optimize for the common case, which is likely a 32-bit OS you may or may not want to use. In a system with less than 4GB the BIOS must choose between providing as much as possible below 4GB to benefit 32-bit legacy OS users or raise one whole DIMM module above the 4GB ceiling to benefit 64-bit OS 's at the loss of DRAM to a much more memory limited 32-bit OS. The current release of the the S2885 bios incorporates the benefit to a 32 bit OS in regards to memory allocation. We have an alternative beta version that addresses the module being moved above the 4GB ceiling and that can be found on our FTP site: ftp://ftp.tyan.com/Chipset_AMD/K8/2885BIOS/" So basically, Tyan finds it more important to release a product that does not live up to it's potential so that it can satisfy the nincompoops who are running a 32-bit OS on a 64-bit capable processor, even though a 64-bit OS exists now? But, since they do offer this alternative BIOS, I wondered if any of you have tried it. Ken -- Ken Siersma, Software Engineer EKK, Inc. phone: (248) 624-9957 fax: (248) 624-7158 http://www.ekkinc.com -- "Our lives begin to end the day we become silent about things that matter." -MLK Jr.