Can't get 8-Gb loaded onto my Intel MB

[petermuriana]

Intel MB: D955XBK (8-Gb limit)
OS: Win 7 64-bit

I have 2x 2-stick packs (someone mentioned I should have a 4-stick quad-pack?)

F2-5300CL4D-4GBPQ
- CL 4-4-4-12
- 1.8v-1.9v
- DDR2-667 PC2-5300 2GBx2

I can only get it to boot with 2 sticks, in either the black or blue memory slots. I've tried several combinations....works with all my sticks, but only 2 at a time.

From MB manual:
• Main Memory Four 240-pin SDRAM Dual Inline Memory Module (DIMM) sockets
• 667/533 MHz dual channel DDR2 SDRAM interface
• Designed to support up to 8 GB of system memory

NOTE
To be fully compliant with all applicable Intel SDRAM memory specifications, the desktop board
should be populated with DIMMs that support the Serial Presence Detect (SPD) data structure. If
your memory modules do not support SPD, you will see a notification to this effect on the screen at
power up. The BIOS will attempt to configure the memory controller for normal operation.
The desktop board supports dual or single channel memory configurations defined below:
• Four 240-pin Double Data Rate 2 (DDR2) SDRAM Dual Inline Memory Module (DIMMs)
connectors with gold-plated contacts.
• Support for:
⎯ Unbuffered, non-registered single or double-sided DIMMs
⎯ ECC and non-ECC DDR2 667/533
⎯ Serial Presence Detect (SPD) memory only
⎯ Memory configuration listed below:
• Up to 2.0 GB utilizing 256 Mb technology
• Up to 4.0 GB utilizing 512 Mb or 1 Gb technology
• Up to 8.0 GB utilizing 1 Gb technology

System Memory Features
The board has four DIMM sockets and support the following memory features:
•1.8 V and 1.9 V DDR2 SDRAM DIMMs
•Unbuffered, single-sided or double-sided DIMMs with the following restriction: Double-sided DIMMs with x16 organization are not supported.
•8 GB maximum total system memory
•Minimum total system memory: 128 MB
•ECC DIMMs and non-ECC DIMMs
•Serial Presence Detect
•DDR2 667 and 533 MHz SDRAM DIMMs

[petermuriana]

I found this... does this mean that all this other stuff takes away from system memory, and that even though it says there is an 8-Gb limit, I can't even achieve that because of all these other resources?

2.1 Memory Resources

2.1.1 Addressable Memory

The board utilizes 8 GB of addressable system memory. Typically the address space that is
allocated for PCI Conventional bus add-in cards, PCI Express configuration space, BIOS (firmware hub), and chipset overhead resides above the top of DRAM (total system memory). On a system that has 8 GB of system memory installed, it is not possible to use all of the installed memory due to system address space being allocated for other system critical functions.

These functions include the following:
• BIOS/firmware hub (2 MB)
• Local APIC (19 MB)
• Digital Media Interface (40 MB)
• Front side bus interrupts (17 MB)
• PCI Express configuration space (256 MB)
• MCH base address registers, internal graphics ranges, PCI Express ports (up to 512 MB)
• Memory-mapped I/O that is dynamically allocated for PCI Conventional and PCI Express
add-in cards The board provides the capability to reclaim the physical memory overlapped by the memory mapped I/O logical address space. The board remaps physical memory from the top of usable DRAM boundary to the 4 GB boundary to an equivalent sized logical address range located just above the 4 GB boundary. Figure 16 shows a schematic of the system memory map. All installed system memory can be used when there is no overlap of system addresses.

[petermuriana]

Update.... the 'working solution' posted below, although worked for a little while, eventually failed (found the system shut down).... so still looking for a solution.

I got the answer from Tom's Hardware. Several posters suggested I 'increase the voltage in BIOS', and that worked, changing from 1.8 => 1.9 volts, simple solution from tech-knowledgeable people. Why wasn't that suggested by either company?

Tech service from G.skill and Intel both failed:
1. G.skill tech suggested my problem was I purchased 2 pairs of memory sticks (even though all were the same type of memory, speed, latency, etc) and if I purchased a quad, or 4-pack, that would solve my problem.
2. Intel tech support suggested my motherboard (D955XBK) was not compatible with Win7, even though I told them I had been using it for 2+ years already (as 32-bit) with no problems, but now I have upgraded it to 64-bit and wanted to make use of greater memory allowance with 64-bit.

[supahos]

You do realize the issue is most likely that you mixed memory kits.. more voltage helps hide that fact sometimes, try 1.95 and slowly walk up to 2.0v if nees be to see of that works... the solution you're touting as the right one isnt working either and the only reason you had to raise your dram voltage is the fact you mixed kits... hence gskill's answer