matched pairs ?

Philbert

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Sorry if this is in the FAQ sticky but i'm quite confused. My parents have a dell computer with 256mb (2 *128) of DDR 333mhz memory. It is painfully slow so i'm going to upgrade the ram. Most of the advice out there is for buying performance stuff but my parents just use the comp for word processing and internet. I understand that it's best to buy matched pairs. My question is can i buy a single say 512mb and remove one of the units and add that making 640mb. Or shall i buy a matched pair making it 512mb of RAM. I don't quite understand wether you have to have matched pairs or not and wether it matters a whole lot. sorry if this has been talked to death already
 

tenstorey

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If its running on XP with 256Meg it will be very slow as it will be accessing the hard drive very frequently. You would notice a huge increase with any extra ram. To be honest matched pairs would only really be good if you were gaming on the computer and it had a decent graphics card in it. Otherwise buy a single new ram stick as you will certainly notice a huge difference.
 

waylander

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The reason for the matched pairs is for both DDR and speed. DDR works much better when the two ram have been tested to work together. The other thing is that both ram will run at the speed of the slower ram, therefore get ram that has the same timings and speed and you'll save some money. Other than that though any DDR ram should work and you will see a performance gain regardless of whether it's matched or not.
 

wun911

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Try and buy another 2 sticks of ram that is identical to the 2 sticks you already have.

I would just take the RAM module to a PC shop show them and ask if they have anything that is exactly the same.

Delll will just use generic stuff like kingston
 

Mondoman

Splendid
The reason for the matched pairs is for both DDR and speed.
Umm, no. The reason is that older dual-channel memory controller designs often require matched pairs, one in each channel, in order to run in dual-channel mode.
DDR works much better when the two ram have been tested to work together.
Nope.

To the OP: more memory is better. What model number Dell are you working with? If we can look it up we can find out what its maximum memory capacity is, what type of RAM it uses, whether it supports dual channel mode, etc. Also, I think you'll find there's no 640MB limit, so 1GB (2x512MB) or 2GB (2x1GB) would be the way to go if the computer supports them.
 

Mondoman

Splendid
Try and buy another 2 sticks of ram that is identical to the 2 sticks you already have.
Not a good idea:
1) The computer may only have 2 DIMM slots.
2) Even if it has 4 slots, that would fill them completely for a total of only 512MB of RAM.
 

flasher702

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They only time you should be even slightly worried about "matched pairs" is if you must run the ram in Dual-Channel. Even then it isn't really necessary if you know what you're doing (newer memory controllers ussually aren't very picky about what ram you give them to run in Dual-Channel). For web-browsing home-office type applications the increasd bandwidth from running the RAM will make no difference.

My advice: get a 512mb DDR333 or DDR400 stick of low-density ram and stick it in with the other ram. That will get you up to 640mb or 768mb depending on how many slots you have and assuming you have at least moderately clean system it should stop swapping to the HD entirely for a Office + Web browser + Anti-virus type situation.
 

wun911

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Try and buy another 2 sticks of ram that is identical to the 2 sticks you already have.
Not a good idea:
1) The computer may only have 2 DIMM slots.
2) Even if it has 4 slots, that would fill them completely for a total of only 512MB of RAM.

1 Is 512 not enouff for word and net surfing?? Or would you like to give him advice on more preformance stuff? Maybe get him a set of TWIN2X2048-8888C4DFs..

2 Is 4 slots an uncommon? My parents dell has 4 slots...
 

wun911

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Mondoman said:
The reason for the matched pairs is for both DDR and speed.
Umm, no. The reason is that older dual-channel memory controller designs often require matched pairs, one in each channel, in order to run in dual-channel mode.
DDR works much better when the two ram have been tested to work together.
Nope.


I think waylander is correct I think matched pairs are better here is why...

http://www.houseofhelp.com/forums/showthread.php?t=38139

I buy matched pairs because it is more stable and does improve preformance.
 

Mondoman

Splendid
The reason for the matched pairs is for both DDR and speed.
Umm, no. The reason is that older dual-channel memory controller designs often require matched pairs, one in each channel, in order to run in dual-channel mode.
DDR works much better when the two ram have been tested to work together.
Nope.


I think waylander is correct I think matched pairs are better here is why...

http://www.houseofhelp.com/forums/showthread.php?t=38139
Sorry, but your link just says matched pairs increase the chances that dual-channel mode will work properly, which is what I said. Matched pairs have nothing to do with DDR, and won't affect speed (other than ensuring dual-channel mode will work properly).