DDR 266 or 133??

Ecs (elitegroup computers) P4vmm2 pentiu...
June 22, 2010 at 13:11:31
Specs: Windows XP, P4 / 256MB
Need Help here
Im confused on what RAM to use on my mobo

Currently my ram is 256mb PC2100 133Mhz

I tried researching thru the net to find what suitable RAM i can buy to upgrade it to 1GB

So i bought this RAM:
512mb PC2100 266Mhz

but the thing is, my mobo doesnt start up and instead makes beeping noise.

I tried to remove and reinstall but still it doesnt work. Now im thinking if I bought thee wrong RAM and shouldve bought a 133 which is near obsolete.

Can someone help me please?

By the way my processor:
P4 478 Northwood

See More: DDR 266 or 133??

June 22, 2010 at 13:42:20
You can't mix 168 pin SDRAM and 184 pin DDR memory.

Your motherboard has a 256Mb stick of PC133 SDRAM in it originally. You bought 184 pin DDR2 memory (133x2=266).

In other words you have single data rate and you tried to add double data rate. Ya can't do that...different voltages and they're handled differently by the motherboard.

Remove the original memory and try the stuff you just bought in the proper slot.

Here's the manual...


1. You have to set a jumper (jp1) for the voltage of the memory you want to use...page 11.

2. You then set jumpers (j2 and j3) as shown on page 12.

3. Read page 18 before you do anything.

The best choice for your motherboard is the one like you just bought.

Remember, you can use 2 SDRAM or 2 DDR but you can't mix 'em.

Download that manual and read the whole thing until you understand what you're doing...it's only 42 pages.


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June 22, 2010 at 13:44:27
You bought the correct type of memory for your motherboard and processor.

266MHz is the effective (double data rate) speed of the memory; 133MHz is the actual clock rate.

Try running one stick at a time. Does it still beep?

I guess I should've taken a look at your board specs first...lol. I was assuming you had a DDR-only board.

edit #2: Although, it sounds like the board was already set up for DDR memory:
"Currently my ram is 256mb PC2100 133Mhz"

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June 22, 2010 at 13:53:06
"Product: Ecs (elitegroup computers) P4vmm2 "

Your mboard has two types of ram slots - two slots are for SDram (the original SDram) - two other slots are for DDR (DDR SDram - the second generation of SDram).

DDR = Double Data Rate - because of the way the module is wired up, it in effect runs at double the rate of SDram - so, e.g. 133mhz DDR ram runs at 266mz on the module.
You get better performance from this mboard model if you install DDR ram (DDR SDram) rather than SDram.
You must install the DDR ram (DDR SDram) in the slots for DDR ram.
The slots are the same length, but the ones for DDR SDRam ram have more contacts in the slots and on the modules, and DDR ram uses a lower voltage.
SDram slots have two bumps in the bottom of the slot, the modules have two notches you must line up with the bumps.
DDR (DDR SDram) slots have one bump in the bottom of the slot, the modules have one notch you must line up with the bump.

You install one type of ram or the other, not both - you have only a max two slots you can use.

If you install DDR ram in a SDram slot, it won't work, and the higher voltage in the SDram slot may damage the module.

If you install SDram in a DDR ram slot, it won't work, but the lower voltage in the DDR ram slot probably won't hurt the SDRam module.

Ram that works in another mboard , or any ram you buy or have lying around, may not work properly, or sometimes, not at all - even if it physically fits and is the right overall type (e.g. SDram, DDR, DDR2, etc.; PCxxxx, xxx mhz) for your mboard. In the worst cases of incompatibilty your mboard WILL NOT BOOT all the way with it installed, and the mboard may not even beep - the ram has to be compatible with the mboard's main chipset, or in the case of recent mboards, compatible with the memory controller built into the cpu.

See response 5 in this for some info about ram compatibilty, and some places where you can find out what will work in your mboard for sure:
Correction to that:
Mushkin www.mushkin.com

Once you know which module ID strings (part numbers) work in your mboard, you can get them from anywhere you like that has ram with those ID strings.

If you have brand name ram, it is usually easy to look up whether it's ID string is in a list of compatible modules found by using your mboard or brand name system model number.
If the ram is generic, that may be difficult or impossible.

E.g. Kingston's list of modules:

Part Number Description Price

KVR133X64C3/256 256MB 133MHz Non-ECC CL3 DIMM
KVR133X64C3/512 512MB 133MHz Non-ECC CL3 DIMM
KVR266X64C25/512 512MB 266MHz DDR Non-ECC CL2.5 DIMM
KVR266X64C25/1G 1GB 266MHz DDR Non-ECC CL2.5 DIMM

Crucial's list:

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Related Solutions

June 22, 2010 at 14:03:18
"Currently my ram is 256mb PC2100 133Mhz"

I'll bet my bottom dollar the current RAM is 168pin PC133. The PC2100 statement is simply incorrect.


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June 22, 2010 at 14:20:19
Does(Do) the original module(s) have two notches in the contact edge, or one?
two = SDram, has 168 contacts (half on each side)
one = DDR ram, has 184 contacts.

All the modules must have either one or the other.

As I recall, at the time this mboard model (and others that had both types of slots) first came out, DDR ram was a lot more expensive than SDram, so SDRam was what most people bought. If the ram has been in it for a long, long time, the original ram is probably SDRam

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June 22, 2010 at 15:12:25
Precisely what I was thinking Tubesandwires. I bought a KM2M a few years back and a 256Mb stick of DDR cost more than the motherboard.

I used it with my PC133 for a month and gave it away.

That board did set voltage and memory type automatically though. If memory types were mixed, it was a "no power to the board" deal to protect the motherboard


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June 22, 2010 at 19:17:12
thanx for the info i found my mobo model in the site you gave me here My Version 7.3 mobo doesnt have SDRAM slot just two DDR slots so i guess im wrong at my post earlier. Ive been researching a lot on what version of P4VMM2 mobo i have. When i used cpuz, it sez there my mobo is V1.0 whch gets me confused though

another thing is i dont see any JP1 on my mobo, honestly. only JP1A1, JP1A2, JP2, J1 and JBAT1

Youre all correct. The previous rAm that is currently isntalled in my system is indeed a 184 pin type DDR.

So i guess i bought the wrong RAM type.
KVR266X72RC25/512 is i think Registered type

yes i did try one stick at a time, even tried to place it in slot 0 then slot 1. It only works on my prev RAM, but beeps on the one i bought..

is there anyway i can make Reg. or ECC type RAM work on my mobo??

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June 22, 2010 at 21:18:17
By the way ive checked my pin configurations and my CPU Freq is set to 100MHz.

I was thinking if i fix it to 133MHz:

1) will i be able to use now my new RAM??


2) will it have a bad effect on the performance of my CPU which is P4 1.8Ghz 400FSB??

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June 23, 2010 at 00:17:45
up post

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June 23, 2010 at 05:12:02
"By the way ive checked my pin configurations and my CPU Freq is set to 100MHz"

That's what it's supposed to be. If you change the CPU freq to 133MHz, you'd be overclocking the CPU from 1.8GHz to 2.4GHz.

"will i be able to use now my new RAM??"

Your RAM problem has nothing to do with the CPU freq. You simply bought the wrong RAM = "i think Registered type". From your manual:

"This mainboard supports unbuffered DDR SDRAM only. Do not attempt to insert any other type of DDR SDRAM into the slots."

Generally, registered = buffered, unregistered = unbuffered. Take the new RAM back & exchange it for the right stuff...unbuffered/unregistered/non-ECC PC2100 (aka DDR266).

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June 23, 2010 at 20:52:33
Ok then so their is no way my new RAMM will work T_T


Oh well i guess i have to buy another. But im hoping to have it exchanged though

good thing it didnt fry my mobo

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June 23, 2010 at 20:54:58
Just to ask what types of RAM can i Place into my mobo other than DDR 200 and 266?

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June 24, 2010 at 23:21:27
up post ^_^

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June 24, 2010 at 23:36:40
Doesn't make any difference what you might be able to stuff into that board. With the processor you have, the 100:133 (3:4) ratio is what you want to run.


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June 24, 2010 at 23:48:26
Im planning to install a 1GB PC2100 DDR266

will this work??? my processor:

P4 1.8Ghz 400FSB bus speed 100Mhz Cache 512Kb

will there be any conflicts between my proc and that RAm type??

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June 25, 2010 at 00:13:27
That's the combination you want. Don't spend any more than absolutely necessary on that thing.


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June 25, 2010 at 00:23:05
its not really that i want that combination

i want to make sure first if that will work. I dont want to buy wrong stuffs again T_T

i need your guidance ^_^

if i change my proc to a P4 2.8Ghz 533FSB Cache 512 wil it stilll work with the 1GB PC2100 DDR266 RAM????

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June 25, 2010 at 09:07:14
The 2.8 would match with PC2700 memory.


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June 26, 2010 at 00:35:05
oh dear you mean i have to use PC2700??

T_T then ill have to stick with my proc for the mean time.

thanx for the tips man ^_^

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