RAM compatibility

[Lelouch]

I tried googling this but no good answers came up, anyway ,my sister's PC has a 126mb RAM and I got a spare 512mb RAM card/chip.
I'm almost certain that RAM goes in 126mb/126mb, 512mb/512mb if you want 2 RAM chips/cards and not 126mb/512mb pairs.
I just need someone to clarify the above please

[Potatochobit]

no no, its ALOT more complicated. the speeds have to be the same. post the exact number on the memory stick, something like PC2700 DDR2 512mb.

older computers almost always have to be run in pairs like u said, if u can take the sticks to a computer store, they can get u the right parts.

[hobbes_fan]

lets see there to my knowledge over the last ten or so years there's been 4 or so types of RAM: SDRAM (oldest) ddr(old), ddr2(recent, generally the standard), ddr3(very new). havent seen any DDR or DDR2 in 128mb configs ever. So i'd say it's sdram. I haven't seen any SDRAM sold in years. But they should be very cheap. I sincerely doubt that your 512 if its from a recent PC would be compatible.

Oh and if it is using SDRAM still, RAM isn't going to help a lot.

[aeriolewinters]

Maybe I can Help you, is it a SIMM or a DIMM? and How many pins

[krysinello]

There are several factors that go into upgrading ram. Having 128mb ram mens you either have SD or DDR. So the ram stick you have needs to be one of those 2 first of all, and your mobo must support that chip and the speed it runs at.

But your mobo must support the ram you have, if it doesn't then it wont work. What you need to check is what kind of ram your mobo takes and its compatible speeds. For example if your mobo supports DDR133 to DDR400(guessed lower speed) then it can support any ddr chip labeled that way. If its an SD chip, then the mobo must support SD ram and the speeds.

[Lelouch]

my sister's PC : 256mb DDR SDRAM
not 128mb sry

just need to dig my RAM out later

[aeriolewinters]

I believe that higher versions of DDR(400 and 533) will work but they will run at lower speeds.

[arcadeplayer987]

I have 1gb of Ram Pc3200 but it run's only at 2700 because the motherboard are not suporting more than 333MHz.I think is the same situation for you and it will work at lower speed

[Lelouch]

my ram is ddr 400(2.5)512mx8
if it hlps

[grey_moon]

My favouritest trick when buying ram is to go to

http://www.crucial.com/

Select your mobo etc and then grab the list of what is compatible ram from them and then buy else where...

sorry crucial (I do buy from them some times when they work out cheaper)

[Lelouch]

thx for the help guys. everything worked out fine

[reflection]

Compatibility is not very straightforward. However, as long as you have the correct ram type, you can drop it onto the motherboard. It will auto adjust all available ram sticks to run at the speeds of the slowest stick. As grey_moon suggested, if the manufacturer of the ram has a compatibility list, go check it. You might even want to look further than that, so not just compatibility to motherboards but in usage with ram from other oem's. Although that may be too much work so most just stick it in and pray all goes well. Well actually, it should work out most of the time. =) You could say, though, that ram compatibility is an individual experience(unless someone else out there has exactly the same setup and can offer you advice).

Oh, and glad it worked out for ya.

[Zero Shinohara]

Well, I don't know if a lot of people have had the same experiences as I did, but I have to let everyone know, since it might help in the future.

My PC had a 128 DDR233 2300 ( not sure about the frequency, but it's something around those lines ), and I bought a new 256 one to give it a little upgrade. But the new one I bougth was 266/2700 and, although the motherboard was supposed to support that speed, I started to have terrible problems with it. Every two-three weeks, I had a major registry crash, in which I would lose everything unless I spent hours/days doing backups and saving everything to CDs. And since I had no idea of what could be causing it, I started to think it was the HD itself that was causing all the trouble.

This went for about a year, until I had a new crash and started to get really pissed. So I started to look around for reasons why this could be happening, but I just couldn't get a straightforward answer. So, to make a long story short, I replaced my PSU, my HD, cooling and what-not, roughly a $200 upgrade just to get the same stupid problem two weeks later. So I thought to myself "Well, I tried everything else... let's see what happens without the 2700 stick I bought.". Eureka, it worked.

So, the moral of the story is: If you have a system that you're not sure can handle memory of different speeds, just buy RAM that's identical to the one you already have. It's not something that should take a lot of time to figure out if you look in the right places, but if you screw this up, you can get a headache very fast.

And even though it worked fine, look out it anything goes wrong: Programs stop working, you get BSODs often, HD crashes, Registry errors and anything that you know isn't normal. If it starts acting up, remove the new stick and do some testing. AND even if it's the same speed and same specs, the stick can be damaged, so look out. Good luck

[Jinto]

Originally Posted by Potatochobit

no no, its ALOT more complicated. the speeds have to be the same. post the exact number on the memory stick, something like PC2700 DDR2 512mb.

older computers almost always have to be run in pairs like u said, if u can take the sticks to a computer store, they can get u the right parts.

It is more like the other way round... in the old days one could easily combine RAMs of different sizes when they were the same type. Today, thanks to such inventions like dual channel-enabled memory controllers this could slow down the throughput of an equal sized pair of DIMMs/SIMMs significantly.