2GB of 333MHz RAM or 1GB of 400MHz RAM?

2048MB running at 333MHz but 1024MB running at 400MHz.
I have an A8N-SLI mainboard and BIOS 1008.
When I install 1GB (2X512) D/C Kit PN - OCZ4001024V25DC-K of OCZ RAM it
clocks to 400MHz but I when I doubled it and have 2GB (4X512) D/C Kit PN
- OCZ4001024V25DC-K it runs at 333MHz without errors.
I read the Asus website FAQ and I tried to manually set it to 400MHz as
Asus specified but I get errors from MemTest86+ v1.60.

Does anyone have any ideas?

 

Bob wrote:

" Does anyone have any ideas? "


You can't use all four slots @ DDR400 with double-sided DIMMs. Sell
them all and buy a 2x 1GB kit.

 

Have you tried 2T Command Rate setting ? It likely isn't listed
in the manual, and requires a recent enough CPU revision, to get
the ability to set 2T Command Rate. Because the BIOS feature is
not documented, I don't know if you are offered Auto,1T,2T as
options or not. 2T setting is the most relaxed.

Also, a little more Vdimm might help. See if 2.7V helps, as 2.6V
is the spec value for DDR400 memory chips.

Here are several links, documenting the need for 2T Command
Rate at DDR400 when using four DIMMs:

http://www.xbitlabs.com/articles/cpu/display/athlon64-venice_3.html

"Athlon 64 processors based on Venice can work with four
single-side DDR400 SDRAM modules without any limitations, and
if there are double-side DDR400 SDRAM DIMMs installed, they
can work at 400MHz with 2T timing."

http://www.anandtech.com/mb/showdoc.aspx?i=2128&p=5
http://www.anandtech.com/mb/showdoc.aspx?i=2285&p=4

HTH,
Paul

 

You cannot populate all four slots and get 400MHz. You must leave at least
one slot empty to get 400MHz. It's in the manual, and on the website.

Bobby

 

I'm using 4 Corsair Value Select 512MB DIMMs in mine at 400 MHz (2T
command rate), and Memtest seems fine. It probably depends on the type
of modules you're using (and possibly the CPU as well).