DDR/General Memory FAQ (2003)

[budbd]

So what you are saying is that I cannot have 2x256mgb ram chips with 2x128mgb ram chips? Jeese, I would hate for the 128mgb ram chip sets to go to waste, though I really would like to be able to get away with only 512 mgb of ram right now, but if the aforementioned were true, then I would have to by tow more 128 mgb ram chip sets to make 512 mgb of ram. According to what I have read in this thread, and my Dell users manual, it seems that I have to have two of any kind of chip set in order to have dual channel status memory. I guess I could technically get a set of 128 mb of memory to get a total of 512 mb of ram.

Actually it might be cheaper to do so. All I plan on doing is playing a flight simulation game, but I believe I might need at least more than 512 mgb of ram. I also thought about getting pc3200 ram chips instead of pc2700 ram chips, even if a slight loss of operational mhz memory speed cause next year I might want to install a 800mhz fsb hyper threading p4 cpu in place of my standard p4 cpu, that is, if I actually needed it, that way I would already own the right memory, or at least 2x256mgb of that memory. Jeese, for my uses, I still think I will never need more than a gig of memory, so I might end up with 4x256mgb ram chips in my memory slots.

I actually do not like the whole dual channel ram "matched pair" memory purchasing principal, cause that forces a consumer as myself to be obligated to purchase "two" instead of "one", which something really stinks of something, oh, I don't know, something really crooked, or unethical. Likely I would get just fine performance even if I had just one each of different types of ram.

[Karnevil9]

No, if your users manual says that you can use any combination of ram, then you are alright. Some board manufacturers state specific configurations of rams that you can only use. It is one of those things to check so you don't wind up wasting money.

As far as the matched pairs of memory are concerned, I wouldn't worry about it. I only mentioned it is available to those who want it. Usually serious gamers. I have never used it myself, so I don't know if there is any real advantage to it.

I would probably do the same as you if upgrading. If I thought I would want to have higher speed ram in the future, I would purchase it as i go along now even if the speed is clocked down for a time until then. The speed difference between those two will not be that noticeable, if at all.

[budbd]

Yes, my new Dell manual says ""If you install mixed pairs pc2700(DDR 333-MHZ) and pc3200(DDR 400 mhz) memory, the modules function at the slowest speed installed"., which means I could in theory use pc 3200 333 mhz for now. It does talk of 333 mhz memory only operating at 320 mhz if used with a 800mhz fsb.

Actually, maybe I am only guessing I can actually put pc3200 ram chips into a presently 533 fsb, but of course I use PC 100 memory in my old gateway that was made for pc66, and the faster ram chips downclock to pc66, so the same should be true for the current stuff, seemingly, something I just figure is true, and would likely order now.

[Karnevil9]

It seems to be a general rule that the memory will clock down to the slowest component used. In your case mixing the 400 mhz and the 333 mhz ram togther will cause the faster sticks to clock down to the 333mhz. Put them altogther with a 266 fsb CPU and they all clock down to 266mhz.

[budbd]

For me, I made a decision today to just stick with pc2700, bought 4x256mb ram sticks used on ebay, upgrades from Dell machines, great for my Dell. For 1 gig total it cost me $174 shipped, and since all four slots on my motherboard will be filled, I will auciton off or sell outright my 2x128mb ram sticks to offset the cost, likely will get at least $40 for them cause they will be only two months old when I get my replacement ram. Basically 1 gig of high quality dual channel ram with 2.5 cas latency advertised and barely used, and will cost eventually only $130 or less.

[fused]

floppyman.. i'm kinda need ur help...i'm planning to buy P4 mobo 800FSB and using Celeron 478 pin.. and planning to get 128 RAM DDR333 because the processor bus speed is already lower.. Because of the celeron processor runs in 400mhz and the mainboard 800mhz and the RAM 333mhz, will there be unstability in performance?

[Floppyman]

Hi,

First of all you'll need to make sure that the motherboard supports the 400mhz FSB. Some of the 865 and 875 chipset based boards only support the 533mhz and 800mhz FSB's. I think the 333mhz would work it might just run slower. You'll have to see you might be able to run the FSB (400mhz in your case) and ram speeds asynchronous (at different speeds). Your motherboard might provide you with this option. Let me know if yo have further questions and HTH

[fused]

yeah .. i'm pretty sure that ASUS P4V800-X can support 400, 533 and 800Mhz.. this is the mobo that i'm kinda buy in future...and it support DDR400, DDR333 and DDR266...but it doesn't support dual channel anyway...well, before i got stuck in future, do you think it worth to have this mobo because i'm only using Celeron and probably upgrade to P4 proc in future..

[Karnevil9]

Since the mobo is the heart of your computer, you should plan to buy one that is comapatable with all the upgrades you may do in the fututre. If you think you may want to upgrade to an 800 fsb CPU and dual channel support, SATA etc in the near future, you should buy a mobo that supposts that now. Otherwise you just have one more compoent you will have to replace. You can take advantage of the dual channel support right away.

[fused]

Originally posted by Karnevil9 Since the mobo is the heart of your computer, you should plan to buy one that is comapatable with all the upgrades you may do in the fututre. If you think you may want to upgrade to an 800 fsb CPU and dual channel support, SATA etc in the near future, you should buy a mobo that supposts that now. Otherwise you just have one more compoent you will have to replace. You can take advantage of the dual channel support right away.

yeah.. thanx karnevil9.. i'll take your advice.. but i'm just curious about stability of the system if i mixed up all the hardware with different bus speed..

[Karnevil9]

As general rule of thumb it will operate at the bus speed of the slowest component. To my knowledge, If the parts are good quality and copmpatable, stability shouldn't be an issue.

[TennBikeBerk]

I have a question about my laptop. I have PC2100 DDR RAM. My motherboard's FSB is rated at 400mhz. Should I upgrade my memory? Will I notice a difference? If so, where is a good place to get some?

[speeddude2000]

nope its already optimized....pc2100 ddr is for 400mhz (intel) fsb. unless your overlcokcing...

[TennBikeBerk]

Good to hear. Thanks speeddude2000.

And overclocking on my laptop....well it's hot enough already in there. Lol.

[Floppyman]

Originally posted by speeddude2000 nope its already optimized....pc2100 ddr is for 400mhz (intel) fsb. unless your overlcokcing...

Technically, pc1600 DDR was designed for the 400mhz FSB cpu's. pc2100 was meant to be used to be used with 533mhz FSB's. However, you can of course use pc2100 with a 400mhz FSB cpu as well. It will either be downclocked to pc1600 then or, if your motherboard supports it, you can run the ram speed asynchronous from the FSB (i.e. not 1:1) to obtain optimal performance.

HTH

[jgis19]

I have searched this thread but i must be missing something! My motherboard is an Asus P4PE,CPU P4 2.4b,two sticks of Mushkin 512 mb 2700 mhz black. I can't seem to get it to work in dual channel mode,even though the Asus site says this board supports it. What am I doing wrong? Wrong slots,something in bios? Any help would be appreciated.

[bigandy]

My guess would be that the sticks of RAM aren't in the correct slots. Check your manual to see which slots are used for Dual Channel. If you can't find the information there, try looking at the slots. There may be two slots which are the same color, and are different form the other(s). If so, that's probably your best bet for running in Dual Channel.

[Panama Red]

Originally Posted by jgis19 I have searched this thread but i must be missing something! My motherboard is an Asus P4PE,CPU P4 2.4b,two sticks of Mushkin 512 mb 2700 mhz black. I can't seem to get it to work in dual channel mode,even though the Asus site says this board supports it. What am I doing wrong? Wrong slots,something in bios? Any help would be appreciated.

I ran that same system for a little over a year and just sold it to a friend. Don't think it supports Dual Channel. That was introduced with the 865 and 875 Chipsets. A bios update will allow use of a P4c at 800fsb and one stick of PC3200 memory but still no Dual Channel. Here's the Asus info on that board.


http://usa.asus.com/products/mb/sock...e/overview.htm

[jgis19]

Thanks for your help,I was lead to belive that this board would support dual channel,but if it doesn't so be it. It is still a sweet setup,and probally runs as fast as i will ever need. Again thanks for all your help.

[SuperBeastDJ]

hmm corsair XMS 2x512 pc3200 400mhz ram has cas 2 but the ram im getting corsair 2x512 pc3200 400mhz has 2.5 cas latency but is 64$ more Is it worth it to go with the xms ram?

[speeddude2000]

if you are overclocking, get the xms. if not, then stick with the cas 2.5, itll do fine even if your a gamer(but if youre really serious about gaming youll get the cas 2, not too much of a diff though)

[SuperBeastDJ]

well im already 400$ over my 800$ goal so o well cant hurt lol

[General Lee]

Could someone tell me what the difference between PC3200 & PC400 RAM is? They both run at 400MHz, right? I ask b/c I need some RAM & PC400 is more expensive.

[bigandy]

Do you mean PC3200 and DDR 400? Because those are the same thing. There is PC4000, which runs at a much higher speed of 500MHz.

[General Lee]

Thanks for clarifying, I did mean to say DDR400. That is a relief b/c I was disheartened at the price of PC4000 when I saw it. DDR400 is much more in my price range!

[zip86]

Can someone explain the difference between SODIMM and DIMM?

[bigandy]

DIMM stands for Dual Inline Memory Module. Basically a small circuit board with memory modules on it. It has a 64-bit path; and today's DDR memory modules have 184 pins.

SODIMM stands for Small Outline Dual Inline Memory Module. This is similar to a regular DIMM, however it usually has a lower pin count and is made for for laptop computers.

[Ender_Wiggin]

I was just wondering up upgrading my ram for the new dell dimension 2400 I bought. I want to get it from 256 to512 but on the dell site it states that the computer uses Shared DDR SDRAM at 333MHz. My question is what is that. I know what DDR and Sdram are but I thought they were different. To anybody wgho could help me here i would be very thanfull. also here is the link to the page at dell. http://configure.dell.com/dellstore/...C_FEAT_CHBC4P2

[Panama Red]

Originally Posted by Ender_Wiggin I was just wondering up upgrading my ram for the new dell dimension 2400 I bought. I want to get it from 256 to512 but on the dell site it states that the computer uses Shared DDR SDRAM at 333MHz. My question is what is that. I know what DDR and Sdram are but I thought they were different. To anybody wgho could help me here i would be very thanfull. also here is the link to the page at dell. http://configure.dell.com/dellstore/...C_FEAT_CHBC4P2

First off you'd be better off posting your question in a new thread. But the best place to buy memory for a prebuilt machine like your Dell is at www.crucial.com. Use their Memory Configurator and buy direct from them. Price is competitive and the memory is guaranteed to work.

[zip86]

You can get 2 256MB DDR PC2700 333MHz or 1 512MB DDR PC2700 333MHz
The 333MHz just mean it's compatible with PC2700's.