quick question on memory

[Dutchmaster420]

i currently have 2 sticks of 512mb pc3200 in the dual mode or whatever i fogget what its called

i want to upgrade to 2gb

should i get 2 more sticks of 512mb or just get 2 1gb sticks

basically my question is, if i have 4 sticks of 512mb will it stay in the dual mode

 

[mobobuff]

I remember hearing that 2 sticks in dual channel run faster than 4 sticks in dual channel. Overall capacity being the same, of course. Probably has something to do with bus width *shrug*.

Though I'm very possibly wrong, wait for someone who knows more.

 

[Dutchmaster420]

alright thanks

 

[imported_ColinT]

A turorial:

http://www.bleepingcomputer.com/tutorials/tutorial122.html#types


Pertinent quote from there:

"Dual Channel Memory - There is no difference between Dual Channel DDR Memory and ordinary DDR Memory, it's the motherboard that is different. Systems that have dual channel capabilities can effectively double the bandwidth of the Memory Bus by accessing the RAM modules in pairs. To use Dual Channelling you would purchase RAM in matched pairs and install it symmetrically across the memory channels."

 

[Dutchmaster420]

alright....so should i just buy 2 more 512mb sticks or just get 2 1gb sticks?

 

[IdaGno]

Originally posted by: Dutchmaster420
alright....so should i just buy 2 more 512mb sticks or just get 2 1gb sticks?

The Mothe rShip Is Calling

1GB DDR DIMMs began appearing in the market over a year ago, but it wasn't until mid-2005 that 1GB DIMMs with reasonably fast timings became widely available. These faster 1GB DIMMs finally made the choice of 2GB memory kits to be a reasonable choice in a market that had been dominated by fast DDR 512MB DIMMs.

There are many reasons to choose a 2GB kit over a 1GB kit or 4 512MB DIMMs. Two 1GB DIMMs on the AMD Athlon 64 can still run at 1T Command rate, instead of the 2T required by the 4x512MB DIMMs needed for 2GB with 512MB DIMMs - a definite advantage for the 1GB DIMMs. On the other hand, until recently, the available 1GB DIMMs were generally much slower than the fast 2-2-2 DIMMs that were commonly available in 512MB DIMMs. We normally saw 3-3-3 or 3-4-4 or slower timings for 1GB DIMMs. These poorer timings for 1GB DIMMs took away most of the advantage for the 1GB 1T Command Rate.

 

[engiNURD]

DDR400 in dual channel mode with 4 sticks would have a command rate of 2T, which would affect performance. For best performance, get 2x1GB sticks and sell your 2x512MB sticks. If you don't care about the performance hit, then get an extra set of 2x512MB.

 

[Dutchmaster420]

alright thanks for all the info

 

[soydios]

Memory can be accessed with less latency (faster) with less memory modules per channel. So, you want two modules in dual channel mode, one in each channel.

The rule with memory is that you want to have the maximum number of channels with the minimum number of modules in each channel. So, on a desktop dual-channel setup, you want two modules. In a Mac Pro (workstation chipset, four memory channels), with two modules, you won't have all the channels active, and you'll get half the bandwidth. With four modules, you'll have one module per channel, so all channels will be operating at their fastest. With eight modules, you'll have two per channel, so all channels will be operating, but not at their fastest speed or latency.