0 Replies Latest reply on May 19, 2009 7:35 AM by jimscn2r

    DG43NB motherboard, setting BIOS Manual memory timings issue


      I have been having problems getting my new DG43NB mbo to work with 2 DIMMs of memory for dual channel mode. I started with a pair of Kingston KVR800D2N5/1G  1GB  DIMMs.

      My minimal system (no add-in cards) consists of a E5200 Dual core system running XP with a VGA monitor attached to the built-in video. I have tried both BIOS ver 77 and 82. The kingston memory is read, by the BIOS, in Auto Memory config mode, as 5-5-5-18 (tCAS-tRCD-tRP-tRAS) @800Mhz.


      My problem is that my system locks up with the display mostly OK but there are a few rectangular black patches. The mouse is dead and kybd has no response. I ocassionaly see a few flickering pixels(dma update?). This usually happens a few minutes after getting XP up. The problem does not occur when I run with only one (tried both) DIMM.

      I decided to try and slow down the system memory timing by using the manual settings.

      When I tried this I found that I could set the first 3 parameters to any value in the range of {3,4,5,6,} clocks.

      The tRAS parameter could only be set to a valu in the range {10,11,12,13,14,15}.

      I tried a setting of 6-6-6-15, but that did not work either, system still locked up.

      I went to Kingston website and found that my CL5 memory was not on the "approved" list for the DG43NB mbo.

      The Kingston site:


      said I needed their KVR800D2N6K2/2G CL6 memory (6-6-6-18).

      The Intel "tested" memory site:


      indicates that I can use the Kingston KVR800D2N5/1G-SP CL5 memory that I have been testing with!

      Who do you believe?


      I would like to know the following:

      1) Why doesn't the BIOS allow me to manually configure the tRAS timing to 18?

           I assume the 18 clocks come from a SPD ROM on the SDRAM.

      2) Is it possible that a tRAS value of 18 is not supported on the DG43NB?.

           I would assume the BIOS is ported to run on the DG43NB.

           You would think(hope) the BIOS would complain if a memory SPD value was too high (18>15) or too low

      3) Why do all of the DG43NB specs ignore the min/max (tCAS-tRCD-tRP-tRAS) ranges?

           How am I supposed to determine which memory should work in my DG43NB.

           Maybe my memory is OK and the DG43NB is bad.





      Thanks for any help