SC420 DDR2 memory in pairs?

[Someone]

Archived from groups: alt.sys.pc-clone.dell (More info?)

I have a Dell SC420 with 256Mb DDR2 PC2-4200 (533MHz) ECC Unbuffered. To
upgrade to 512 I bought a non ECC 256 stick from Crucial which will not
work, you can't mix ecc and non ecc. No one apart from Dell (of course)
sells ECC 256 ram and dell's are stupidly expensive.

I had a look in the manual and it states that:

1. If only one memory module is installed, it must be installed in connector
DIMM_1 --- obviously!
2. If only one memory module is installed in connector DIMM_1, its capacity
must be 256 MB
3. If more than one memory module is installed, the memory modules should be
installed in pairs of matched memory size, speed, and technology.
4. Memory modules should be installed in ordered pairs in connectors DIMM_1
and DIMM_2, and then DIMM_3 and DIMM_4

So it seems that to upgrade I either need to buy the expensive 256 stick
from Dell to get 512 or buy 2x512s from crucial because they must be bought
in pairs!

However the manual then shows a table of possible memory configurations:

Table 6-1. Sample Memory Configurations
Total Memory DIMM_1 DIMM_2 DIMM_3 DIMM_4
256 MB 256 MB none none none
512 MB 256 MB 256 MB none none
1 GB 256 MB 256 MB 256 MB 256 MB
1 GB 512 MB 512 MB none none
1 GB 1 GB none none none
2 GB 512 MB 512 MB 512 MB 512 MB
2 GB 1 GB 1 GB none none
3 GB1 GB1 GB 512 MB 512 MB
4 GB1 GB1 GB1 GB1 GB1

The 1GB option is for one 1gig stick in only DIMM_1 !!! Does this mean I can
slot a 512 in DIMM_1 too????

 

[Guest]

Archived from groups: alt.sys.pc-clone.dell (More info?)

"someone" <someone@noone.com> wrote in message
news:41dbce38$1@nntp.onyx.net...
>I have a Dell SC420 with 256Mb DDR2 PC2-4200 (533MHz) ECC Unbuffered. To
> upgrade to 512 I bought a non ECC 256 stick from Crucial which will not
> work, you can't mix ecc and non ecc. No one apart from Dell (of course)
> sells ECC 256 ram and dell's are stupidly expensive.
>
> I had a look in the manual and it states that:
>
> 1. If only one memory module is installed, it must be installed in
> connector
> DIMM_1 --- obviously!
> 2. If only one memory module is installed in connector DIMM_1, its
> capacity
> must be 256 MB
> 3. If more than one memory module is installed, the memory modules should
> be
> installed in pairs of matched memory size, speed, and technology.
> 4. Memory modules should be installed in ordered pairs in connectors
> DIMM_1
> and DIMM_2, and then DIMM_3 and DIMM_4
>
> So it seems that to upgrade I either need to buy the expensive 256 stick
> from Dell to get 512 or buy 2x512s from crucial because they must be
> bought
> in pairs!
>
> However the manual then shows a table of possible memory configurations:
>
> Table 6-1. Sample Memory Configurations
> Total Memory DIMM_1 DIMM_2 DIMM_3 DIMM_4
> 256 MB 256 MB none none none
> 512 MB 256 MB 256 MB none none
> 1 GB 256 MB 256 MB 256 MB 256 MB
> 1 GB 512 MB 512 MB none none
> 1 GB 1 GB none none none
> 2 GB 512 MB 512 MB 512 MB 512 MB
> 2 GB 1 GB 1 GB none none
> 3 GB1 GB1 GB 512 MB 512 MB
> 4 GB1 GB1 GB1 GB1 GB1
>
> The 1GB option is for one 1gig stick in only DIMM_1 !!! Does this mean I
> can
> slot a 512 in DIMM_1 too????
>
>

I think the socket configurations are arranged in this manner (they are
numbered on the 8400 IF it is similar):


>>>>>>>>>>>>>>>CPU<<<<<<<<<<<<<<<<<<

---------------------socket 1------------------- white clips
-------------------- socket 3 ------------------ black clips


-------------------- socket 2 ------------------ white clips
-------------------- socket 4------------------- black clips


Look for a single matching 256mb stick on ebay, as I bet others have tossed
one with this same problem, or try the www.crucial.com configurator by
changing the entered number from 2 to 1 when you toss them in the cart.
Also check www.4allmemory.com . In theory, the 2 x256 matching would go in
socket's 1/3.

For 1gb, 2 x512, same thing. The DIMM clips should be colored to match for
proper operation.

Is there no option to disable ECC in BIOS?



Stew