what ram to buy?

crackdaddy30

sup all, i need some help to which ram i should purchase, i had a pair of apacertech x2 512mb pc3200's. well one of them just went dead on me, iam looking for a raplacement to use with my current stick, to be compitable to run in dual channel agian, or should i buy a x2 256mb kit like ocz or corsair, but if i do that well i be able to use my apacer ram in the 3third slot, iam kinda confused how i can config this thanks!!!

H3X4D3C1M4L

Ditch all the old RAM and get a new set of OCZ dual channel modules. The warranty on them is insanely good. And so is the overclocking and performance.

Not worth sacrificing the dual channel speed for the 3rd stick RAM capacity advantage

PangingJr

there are 2 channels exists on many of the motherboards for desktop computer, each channel has 2 DIMM sockets, total of 4 DIMM sockets are available on it.

like this...
Channel 0 : DIMM socket-1, DIMM socket-2
Channel 1 : DIMM socket-3, DIMM socket-4

AFAIK, as of today there are 4 system memory configurations/styles or this could be called as memory modes of operation,
and they are:
1) Single Channel
2) Dual Channel Interleaved (in the 2 channels, each memory modules size must match)
3) Dual Channel Asymmetric.
-----
4) Dual Channel Interleaved operates under Intel Flex Memory Technology (this mode can be found only in Intel 965 chipset boards).

in system that support Dual Channel technology the best is to have the system operates in the Dual Channel Interleaved mode.

as for your case example, IF you buy a "x2 256mb kit like ocz or corsair" and then install the 2 memory modules...
as one in the DIMM socket-1 (of the Channel 0) and another one in the DIMM socket-3 (of the Channel 1),
then your system is operated in the Dual Channel Interleaved mode.
this also true in many motherboards that you can also install the 2 modules in to the DIMM socket-2 and DIMM socket-4, and the system is also operating in the Dual Channel Interleaved mode depending on the design and chipset that is used on the boards.
and then if you also install the old 512MB memory module, then the system will be operated in the Dual Channel Asymmetric mode instead, and in most cases, memory bandwidth would be limited to that of a single channel. however, the system could benefit from having larger amounts of physical memory. my suggestion is that if possible you replace the system memory with a matched pair memory modules of 1GB (512MB each).
if not, then you will have a chance to try the total of 1GB (in the case that you've decided to buy the 2X 256MB and the 512MB still with you) in the Dual Channel Asymmetric mode, and see what happens?

Matth

Some Intel boards even claim to run dual (interleaved) with configurations such as 2 x 256 in one bank and 1 x 512 in the other - I'd like to see some system test utilty proof of a mode like that working.

PangingJr

i think that memory config is not in a Dual Channel Interleaved, but Dual Channel Asymmetric...
i have not tried that with the Intel 965 chipset board yet.

however, in a different config that i just found it out myself weeks ago, it's Intel Flex Memory Technology of the Intel 965 chipset. i've tested it by installing 2x 1GB DDR2 PC2-5300 and 2x 512MB DDR2 PC2-4300 (3 GB total), 2x 1GB DDR2 PC2-4200 and 2x 512MB DDR2 PC2-4300 (3 GB total).
all RAM modules are set of 2 but thay also are in different speed, size and chips, ran under SPD timing, 4-4-4-12 Freq 266 MHz FSBRAM 1:1.
Dual Channel Interleaved was appeared during POST.

-------------------------------

Example of the configurations...

Dual Channel Interleaved...
2x 1GB (or 2x 512MB, 2x 256MB or 2x 128MB or 4 x 1GB or 4x 512MB or 4x 256MB or 4x 128MB) configured dual channel.

Dual Channel Asymmetric...
2x 512MB (configured dual channel, 1GB total in size) + 1 x 1GB.
2x 256MB (configured dual channel, 512MB total in size) + 1 x 512MB.

Single Channel mode...
1x 1GB.
2x 1GB (configured dual channel, 2GB total) + 1x 1GB.
2x 256MB (configured dual channel, 512MB total) + 1x 128MB + 1x 256MB.
< 2x 1GB configured dual channel, 2GB total > + < 2 x 512MB configured dual channel, 1GB total > (except it's operating under Intel 965 platform)

Matth

The manual for an Intel 915 chipset board (D915GAG) Gives the following configurations as dual:

1 pair, DIMM 0 Channel A, DIMM 0 Channel B
2 pairs, DIMM 0 ChA/B and DIMM 1 ChA/B - the two pairs can be different sizes.
2x size "n" in Channel A and 1x size "2n" in channel B

"All other memory configurations will result in single channel memory operation."

crackdaddy30

cool thanks for the tips boys, i personaly thought there was no dif from intel to amd, i assumed there was just one setup up of (dual channel), and for ram i was gonna get 2x256, well was looking to pick a 2x512mb ocz kit pc3500 for $119 instead, not sure if pc3500 is compitble for my a8n-e mobo, or should stick with pc3200? and for my old 512 stick i will keep it for my old 754 asus board, just to add for apacer generic ram i got it too 230fsb muti at x10, htt at 4, stable too, but the highest i got it too was 250fb mutil at x9 htt x3 ram at 415. after saying all this i hope my new ozc can overclock as well, thank guys!!1

crackdaddy30

sorry about the typo hehe