Confused About RAM type - Even though I've done the research...

Hi Guys.

I've been looking around the last few days for RAM for my PC. I thought I had found the right type, but when I went to check it against my motherboard type and a system program (Everest) I got soo lost and confused.

According to my mobo specs, it can take 400, 333 and 266 Mhz speeds. therefore according to a sticky thread by Big B my mobo can take up to PC3200 RAM, is this right??

Secondly, my mobo specs and the system program bith say my memory type is DDR SDRAM - however, the problem is, when I go onto websites to look at the RAM types to see what ones I can buy, I do not know which section to go to, for me its either DDR or SDRAM, there isn't an option which says 'DDR SDRAM' and I do not know which option to select so that I can buy the correct RAM - Is it DDR or SDRAM??

This is a link to my mobo specs in case that helps.

Thanks for any and all help guys

 

yep

old SDRAM was 168 pin memory, although DDR (i think) is a type of SDRAM, DDR is 184 pin memory and DDR2 memory is 240 pin memory, i think the SDRAM was dropped to make selecting the correct RAM less confusing[ot]like its not confusing enough[/ot]so if it says DDR then it is DDR (just igrore the SDRAM part

Edit: please correct me, if i'm wrong

 

Well, I can definitely say that my mobo uses 184 pin RAM so that must mean its just DDR - thanks for that - however, one more issue, when I select DDR, it usually comes attached with DDR DIMM lol - whats this?? Is it again just DDR?

 

DDR = Double Data Rate, DIMM = Dual Inline Memory Module, its just how the memory comes, a DIMM is just what they have called the socket you plug your RAM into, so your RAM is DDR 184 pin and it has to be plugged into a DIMM on your mobo to work

 

Oh right ok, I see now... thank you very muchos

 

no problemo :beer:
BTW: DIMM is also the memory and the mobo socket

 

Thanks for the help man :good:

 

don't worry about it, its why HWF is here :beer: :good:[ot] just glad i was helpful[/ot]

 

Yeah, DDR is SDRAM. So is DDR 2.


There used to be SIMMs, Single in-line memory modules. Single just means that the contacts were only on one side. These used EDO designed chips. I think there was another one too, FPM?
SIMMs ranged between 256kb to 128mb depending on whether you 30 or 72pin sticks.

Then they brought out DIMMs, ie both sides of the stick had contacts. There were 72, 144 and 200 pin DIMMs which supported SO DIMM designed sticks (for laptops) and 168,184 and 240 pin sticks which supported SDRAM design. These are the RAM types that are common today.

The 168 pin SDRAM DIMMs were the 33mhz (?), 66mhz, 100mhz, 133mhz and 166mhz sticks.
Then they brought out DDR SDRAM, the 184 pins sticks. Same as normal SDRAM only it sent data at the beginning of its clock cycle and at the end effectively sending twice the data as normal, hence Double Data Rate SD RAM. DDR ran at 2x133mhz, 2x166, 2x200mhz, or DDR266, DDR333, DDR400.
The PCxxxx part just says how much bandwidth it has. The RAM, CPU and northbridge side of the chipset send data to and throw like theres no tomorrow, PC3200 can send the data (supposidly) at 3.2gB/s which is exactly the same as a Pentium 4a (4x100mhz FSB) so is a good choice.

DDR2 is just more of the same only faster clock speeds which help match the bandwidth the newer CPUs (ie 800mhz FSB ones etc) have.


Just before DDR came out there was RAMBUS (or RDRAM) too. This was class at the time! Dead expensive though, and it still is now!
It came out when the Pentium 3 was a top notch CPU but could provide loads of bandwidth and ran really fast. ie 4 times faster than SDRAM from the time. It could only be used with a couple of chipsets though, the Intel 850i being the one I wanted which only supported Pentium 4s. The Granite Bay was another big hit too.

It ranged from PC600 to PC6400 but PC800 was the main one people had. It was 400mhz RAM giving 1.6gB/s of bandwidth but it was only on a 16bit bus. It even worked like DDR in that it sent data at the beginning and end of the clock cycles. SDRAM was 64bit so the bandwidth of RDRAM was only slightly better than SDRAMs 1gB/s but they brought out 32bit sticks which could be run like dual DDR. This gave it the 64bit bus.
RDRAM sticks went all the way up to 32bit 800mhz which could be run in a dual setup so could hit 6.4gB/s. The same as Dual DDR400 and DDR2 800 which isnt in dual setup. This is 8 years ago remember!

RDRAM didnt use the DIMM setup, they were RIMMS. RIMMS were weird in that if you had the 32bit sticks you had to run then in dual so you needed two sticks. They brought out CRIMMS which were a stick of RAM without any RAM modules on which could sit alongside your "real" RAM stick in dual. They were good because they were cheap! I always wanted a RAMBUS pc, still do! It would be better than what I have now.

 

seems so simple (when you've explained it)
thankies :good:

Edit:

i remember single sided 30 pin SIMMs, but i don't remember single sided 72 pin SIMMS

where they not very common ?