Quote:
Originally Posted by AzzMan
That doesn't work either. Let's go through this from the beginning. From a fresh Win7 32-bit install:
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9) Open the NVIDIA control panel. Manage 3D panel does NOT give Preferred Graphics processor option.
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What am I missing?
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The NVidia Optimus driver needs to find an active primary Intel HD graphics. Some bios will use your GTX460 as the primary if it sees it upon boot.
So ensure you boot with the eGPU switched off. Boot to Win7 with the Intel HD (native LCD) active, standby, poweron eGPU, resume system.
1st-gen i-core and core2duo Dell Latitudes are not allowing 36-bit PCI Compaction
2nd-gen i-core Latitudes are OK as found in
REQ: bios mods to make Vostro/Latitude eGPU friendly .
These systems cannot do a > 3GB of RAM DIY eGPU implementation as have TOLUD=3.5GB. This is seen by perusing the PCI BUS resource in Device Manager and seeing it starts at D0000000 (3.5GB). With the iGPU needing 256MB + system devices in the last 256MB, there is then no free 256MB in 32-bit PCI space to host a desktop video card.
While DIY eGPU Setup 1.x can relocate the iGPU or eGPU to 36-bit space, booting up Win7 will find them moved to 32-bit space OR produce an error 12 if no room for it.
Investigation has identifed that Windows uses the ACPI bios entry PNP0A03 or PNP0A08 to determines the root bridge address range with these systems having an entry that is limited only to 32-bit space. The simplest way to identify if your system is 36-bit PCI allocation compliant is to look for a "large memory" PCI BUS entry in Device Manager as shown below. If don't have it you are limited to 32-bit PCI allocation only.
Dell Inspiron 1440: TOLUD=3.5GB with a rare "large memory" PCI BUS, 4.5GB to 12.375GB allowing 36-bit PCI allocation
This will also be seen in Linux, 64-bit only, 'lspnp' -vv output:
How to get 36-bit PCI compaction working?
Obviously the solution would be to alter the ACPI entry to extend the root bridge to 36-bit space. This was done successfully on a E4300 as part of
Avlan's DSDT override.
Linux has a "pci=nocrs" kernel option to ignore the ACPI bridge allocation. Is there an equivalent option in Windows?
The other way of course is to free up a 32-bit PCI window by contact Dell and asking for a bios with a TOLUD set to 3.25 or 3.0GB. There is no reason to have such a high TOLUD with 64-bit OS. This has been requested in the thread
REQ: bios mods to make Vostro/Latitude eGPU friendly .
Until a fix is made available consider running with just 3GB by physically removing a 2GB RAM module and replacing it with a 1GB RAM module.
It appears too that these systems allow bootup with the external gpu as the primary video adapter. That is another workaround for *all* non-Optimus setups.