Memory question

I am currently running a P4 2.6gb processor with a Asus P4PE motherboard and pc2700 memory. I found a great deal on PC3200 memory but will my motherboard support it? It's the same 184 pin also.

all Intel 845PE chipset (chipset which P4PE boards use) motherboards support 3200 memory..

http://www.asus.com/products/mb/mbindex.htm

Thanks for the link. I actually found my Exact P4PE motherboard and it says it will only support 2100/2700 ram. Here is the link.

http://www.asus.com/prog/spec.asp?m=P4PE&langs=01

There is a very good chance that PC3200 will run perfectly well, though it's impossible to absolutely guarantee it. If it's a really good deal then it's probably worth going for it.

Well the stick of 512mb 3200 was $55 which to me is pretty cheap but if there is a chance of it not working I will pay a bit more and get the 2700 because I know it will work for sure.

Thanks for the help guys!

ok, now I am confused.., that chipset is 533mhz FSB..

my old comp had a 333mhz FSB (DDR333), and it used 2700 memory..

what is with that?

I know that DDR400 is 3200.., so it should work..

hmmmm...

I think......800FSB=PC 3200??

Don't confuse FSB (processor bus) speed with memory bus speed, two different animals. Related, but different. The 800 is the quad pumped processor bus speed (200mhz when not quad pumped). PC3200 uses a 200mhz, double pumped (thus 400mhz) speed on the memory bus.

nope, I am using 3200 RAM right now.., on my DDR400 board..

DDR533 is 4200
I am unsure of 800..., from what I know, DDR800 ram does not exist..

the only thinking that I have is that dual channel has some sort of play in this..

is a 800mhz FSB mean you can have two DDR400 channels?

Byan, you are doing what I said above. Namely, confusing the procesor bus speed(s) with those of the memory bus.

http://www.pcbuyerbeware.co.uk/RAM.htm

A good read for folks in reference to ram

well, I knew they were different things.., but I thought they ended up being equivalent...

I knew that DDR doubles it, making 200 to 400.., ect.

so by quad-pumped you mean Dual Channel DDR right?

I think I understand now.., the ram speed is 200, but is multiplied by 2 from the DDR and then multiplied by 2 again by Dual Channel to make 800
then the CPU needs a 800 FSB to keep up with the end speed of the ram together...

That wiould be fine, except to get the 533 you mentioned earlier, you have to start with a FSB of 133. Then quad pump it.

well then that would only be DDR266, 2100..
and it can support DDR333, 2700

and the board doesn't support dual channel, so I really don't see the use of the 533FSB..

*shrug*

That is the way it goes some times. But I do suggest reading that link a few times, just to get a better feel for this ram business. I reread it a couple times before I even think of upgrading to a new cpu/mobo/ram combination. Saves me from making expensive mistakes.

Byan,

You should definately take a look at links like Train posted (and others). It still seems you aren't entirely clear on the distinction between the FSB (front side bus) numbers and terms one sees (as in say a processor using an 800mhz fsb speed and being quad-pumped, etc) and those relating to the memory bus (DDR, DDR400, PC3200, etc). Again, these are different and independent highways/pathways (buses) on which data is moved. They rely on different clockings/timings, have unique design/architectural aspects, protocols, etc. The front side bus (which is really a term today that has to be used loosely as the Intels don't even use an FSB, but instead use a Hub architecture) is the path(s) from the cpu to the chipset efectively. The memory bus is then another path going from the memory controller(s) to the chipset (there are also other pathways/buses: PCI, AGP, etc).

When you have (say) a P4 processor that requires a 533mhz FSB speed it means that the data transfer speed between the processor and the chipset (not memory) will take place at an "effective" rate equivalent to 533mhz. Now it is an "effective" rate because the actual signal clocking is not 533mhz, it's 133mhz. Instead the technique of quad-pumping is used. This effectively allows getting/putting four pieces of data (signals) on the the bus between the processor and chipset in the time frame of one clock cylce (1mhz). Again though, this timing/clocking and the techinique(s) used to acheive it has nothing directly to do with your memory, its timing, or the methods used to achieve that timing/flow.

Then in regard to the memoy... Now say you have PC2700 memory that you want to use. PC2700 memory is a type of dram that uses (relies on) a DDR (double data rate) protocol in terms of communincation (technique) on the memory bus. With this particular protocol two pieces of data (so to speak) are transmitted for every clock cycle. This is accomplished (in this particular case) by transmitting one piece at the start of a clock pulse (on the "rising" edge") and another at the end of the same clock pulse (on the "falling" edge"). Now PC2700 memory is referred to as DDR33. But it doesn't actually run (use) a 333mhz clocking. Instead it uses a 166mhz clocking. But becasue of the doubling of data moved on the memory bus here per clock cycle a rate "equivalent" to 333mhz is acheived, on the "memory bus" (distinct from the cpu, its bus timing and the method(s) employed in acheiving that timing). And, when you talk about "dual channel" memory that is another whole distinct thing tied in to the movement of data bewteen dram and the memory controller(s).

These were just a couple quick (boiled down) examples to try and (hopefully) make some sense (and disctinction) between some of this stuff. There is (can be) a lot more to these things depending on the particular process, motherboard, chipset and ram you're talking about. The above is not the way things work or are done universally, but it relates to some of what had come up in this thread.