DFI Lanparty 3GB memory

[paul]

Hello all,


I recently bought a DFI Lanparty UT nf3 250Gb motherboard along with
2GB of RAM. It works great and I'm very happy with it. I use it to
develop database application software so the extra RAM really comes in
handy.

The manual says it supports 2GB at DDR400 or 3GB at DDR333. My memory
is currently running at 400. I'd like to buy another 1GB so I can
max it out but I'm curious why the memory speed will drop down to
DDR333 when I do this. Can I get around this by buying faster RAM?
Will all RAM in the system run at this lower speed or just the last
1GB? How much will the lower ram speed impact the speed of the
system?

Thanks for any insight you can provide,

Paul

 

[George Macdonald]

Hello all,


I recently bought a DFI Lanparty UT nf3 250Gb motherboard along with
2GB of RAM. It works great and I'm very happy with it. I use it to
develop database application software so the extra RAM really comes in
handy.

The manual says it supports 2GB at DDR400 or 3GB at DDR333. My memory
is currently running at 400. I'd like to buy another 1GB so I can
max it out but I'm curious why the memory speed will drop down to
DDR333 when I do this. Can I get around this by buying faster RAM?
Will all RAM in the system run at this lower speed or just the last
1GB? How much will the lower ram speed impact the speed of the
system?

It's to do with the loading of the signals on the memory bus. The Athlon64
CPU supports up to 4 ranks (a rank is a side of a DIMM populated with
memory chips) of unbuffered memory at DDR400 and only in the correct slots
with most mbrds. With ECC memory and a mbrd which supports it, you can
usually go up to 6 ranks without dropping speed.

If you check some of the review Web sites, some of them have been able to
violate this rule with high quality memory, though you may have to set
memory timings in BIOS Setup manually and an increase in voltage supplied
to the memory might help too. In some cases, depending on the source,
"high quality" memory could be high speed memory running at "regular"
clocking, e.g. PC4000 memory run at PC3200... but I'd think you need to
have that for all DIMMs in the system. In general it's always better to
match all the DIMMs in a system by mfr and speed.