Memory

[redvette]

Hi gang

Is there an easy way to determine what memory you should use.? I know you have to go by what the book says is right for you particular MOBO. Now what do these #'s stand for, like 333, 400, 2700, etc. How can I tell by these #'s what is good and bad and faster/better then the others. Is it the higher the # the better/faster. And when you install the sticks, and say you have 4 openings, and your MOBO will take up to 4Gs, and say you have a 1g and 2 512G sticks what order should you put them in the slots, or does it make any difference. And it seems there is a little push for matched sets, just how big a deal is this. I noticed they are very expensive too. And is it supply and demand that older DDR stuff is more expensive the the newer DRR2 stuff.??

Thanx........Gunny

[Alaron]

You need to match your memory to your processor. Your motherboard will tell you just the speeds it can accept, but your CPU determines what is best to use.

The numbers are the speeds of the RAM. So DDR-400 runs at 400Mhz effective. (Its really 200Mhz x2 for Double Data Rate, remember). The larger number, the 2700 is the bandwidth of the RAM that you see referred to as "PC2700". That equates to DDR-333 via a formula.

If you have 1GB stick and 2 512MB sticks, it really doesn't matter what order you put them in. Just start at DIMM 1 and fill them in. If you have matching sets, you want to refer to your manual for which slots are Dual Channel. They are usually color coded. Dual Channel gives a small performance boost.

DDR is old-tech at this point. So the limited supply is expensive. DDR2 is the new standard and it is very cheap and in abundant supply.

Hope that helps.

Here is our DDR FAQ thread for your reading enjoyment: http://forum.pcmech.com/showthread.php?t=67892

[redvette]

Hi Alaron

Yes that does explain it a little. You say your CPU will tell you what is best to use. So what #'s should I be looking for to know what is best for my CPU. This one here is a Intel 2.6 Pent 4 8K primary cache, and 512 secondary cache. And I have a 512K stick in #1 slot and a 512K stick in slot 2. What does that tell you.?

Thanx...Gunny

[Alaron]

It depends on the exact CPU model you have. There are 2.6Ghz P4s that ran on 400Mhz, 533Mhz and 800Mhz Front Side Busses.

Also what exact motherboard are you using?

For the RAM: If your motherboard supports dual channel, put the 512 sticks in the slots that it tells you to use for it. If your board doesn't have dual channel, slots 1 and 2 are fine.

[redvette]

I have a Asus P4P800-VM MOBO. And it supports dual Channel. CPU s a 478 celeron Front side buss 800/533/400MHz. Dual channel supports PC3200/PC2700/PC2100. So this is saying PC3200 is best. PC2700 better and PC2100 is good. ?

Thanx.......Gunny

[redvette]

Ok lets put it this way, which is faster/better the higher the # or the lower the #.????

Thanx......Gunny

[Alaron]

The best number is the one that matches your FSB. So you would use PC2100 with a 400Mhz FSB, PC2700 with 333 and PC3200 with 800.

[redvette]

Hi Alaron

Ok so when you look into the handy dandy manual for this MOBO, under FSB it says 800/533/400MHz. Now what.

Thanx......Gunny

[Alaron]

You mentioned having a P4 already. As I mentioned in Post #4, you need to find out which model it is to know the FSB and then what RAM to pair it with.