Foo - PC Memory Upgrade question

I'm thinking about adding RAM to an older computer (currently has 256 MB). I notice in the specifications it lists a "PC2100" memory rating. Do I need to match that? Or does the "PC" rating matter?

I think the PC refers to the type of computer. Have you gone to www.crucial.com (http://www.crucial.com) ?

Great place for memory upgrades.

Have you gone to www.crucial.com (http://www.crucial.com) ?

Checked the site. I read this " Each memory slot can hold DDR PC3200,DDR PC2700 with a maximum of 512MB per slot.*" and this "Because DDR memory is backward-compatible, you can safely upgrade your system with any of the guaranteed-compatible DDR speeds listed below, even if your manual calls for PC1600 or PC2100 speeds."

I assume that means I can get anything under PC2700?

Not wanting to sink much money into a four-year-old computer, I'm thinking of eBaying it. Is there a great risk in used memory modules? I'm thinking that if they work, they work. Or is that wrong?

Mem modules are pretty stout. You should be ok with used ones.

Checked the site. I read this " Each memory slot can hold DDR PC3200,DDR PC2700 with a maximum of 512MB per slot.*" and this "Because DDR memory is backward-compatible, you can safely upgrade your system with any of the guaranteed-compatible DDR speeds listed below, even if your manual calls for PC1600 or PC2100 speeds."

I assume that means I can get anything under PC2700?

Not wanting to sink much money into a four-year-old computer, I'm thinking of eBaying it. Is there a great risk in used memory modules? I'm thinking that if they work, they work. Or is that wrong?
The biggest mistake that most people make are mixing memory modules.
E.g. You should generally avoid mixing pc 2700 with ddr 2100, etc. Also memory with different timing can cause problems. I uusally recommend people either try to find what they currently have and match that or to replace all of the memory.
Less it comes back and bits you in the butt 6 months later in the form of continuous bsod. And yes, it has even happened to mwua. Upgraded a system and added the old memory to my other system. It worked fine for half aof a year and then all of a sudden it began BSODing constantly. Popped out the old old memory module since the memory it originally had 256 and i added 512. Worked like a charm. Don't ask me why it worked fine for 6 months and then decided to start bonking out. I just consider it a lesson learned :p

General best bet is to find out what RAM timings, speed and capacity your current one is and either match it, or replace it.

DDR systems are somewhat sensitive to memory timings, compared to the older SDR base systems.

If the RAM that came with your PC is say 1600, then 1600 and UP is fine....don't go down, unless you like crippling your computer.

and if you need RAM cheap, www.newegg.com like usual (or a certain denizen here might talk up about his services (note: it's not me)).

I Agree with the above. If your system runs its ram at DDR (dual data rate) than its smart to match the size of the RAM module as well.

First you need to figure out how many RAM slots you have on your motherboard to know how many separate modules you can install.

So: if your computer only has two slots, you will need totally new sticks with higher capacity.

If you have 4 slots with only two full, you can add another two matched sticks.

Whatever you buy, just make sure it is matched sticks of the same speed/capacity, otherwise you wont be running in DDR mode which is also crippling your computer.

In my opinion I would just get two sticks of 256mb DDR PC2100 (total of 512mb) OR two sticks of 512mb DDR PC2100 (1gb total)

2100 is pretty Stone Age. I think your computer (at least the generation it hails from) is older than 4 years.

I have a computer that is a few months from being 4 years old and it has
PC3200.

I've mixed all kinds of MEM in computers before and had no problem. Ideally sure it's best to match sets but if you are just trying to cobble together and old machine on the cheap then mix and match works fine (obviously as long as we are talking the same 'form factor' if you will). I never could tell the difference in going from one MEM type to another but the difference of increasing MEM is definitely noticeable. I am pretty sure that on most boards if you mix types then the machine will default to using the slowest speed stick.

jfmckenna,

It's all in what you do with the computer.

For word processing and general web surfing, mix-n-match works fine....but if the user plans on doing any media editing/creation, gaming, or other such demanding work, then it matters.

I tend to go the performance route since some people don't realize what they may or may not do could be more demanding on a PC than they thoght.

Hell, my desktop PC at work can't even handle full-screen video.....but that's just a crappy onboard video.

I am pretty sure that on most boards if you mix types then the machine will default to using the slowest speed stick.

Yep. For the o/p, keep that in mind. If you buy some new pc2700, even if it's compatible with your motherboard, and you mix it in with the 2100, ALL of the ram including the new 2700 will run at the slower 2100 speed. Therefore, no point in spending the extra cash on the faster ram if you plan to keep the old stuff in as well.

Yeah, it's the memory-controller on the MB along with the bus-speed that determines how fast memory is accessed. If this particular MB drives memory at PC2100 speeds, adding faster PC3200 memory will have it still operate at PC2100 regardless. You can upgrade ALL of the slots to PC3200 and it will only run at PC2100 speeds anyway.

I've mixed all kinds of MEM in computers before and had no problem. Ideally sure it's best to match sets but if you are just trying to cobble together and old machine on the cheap then mix and match works fine (obviously as long as we are talking the same 'form factor' if you will). I never could tell the difference in going from one MEM type to another but the difference of increasing MEM is definitely noticeable. I am pretty sure that on most boards if you mix types then the machine will default to using the slowest speed stick.
Yes, you can mix and match, but its better to have each channel-pair matched at least. For instance a good scenario would be if you have 4 slots, Slots 1 and 3 (channel one)would have 256mb 2100 and 2 and 4 (channel 2)would have 256m 2700 or something else. They would all run at 2100 speed though. If you run a channel with different capacities (eg slot 1 w/128 slot 3 w/256) it will default to single date rate mode. So no DDR. It will work, just slower.

Don't go too cheap with "pulls" or used RAM... It sucks when you are trying to figure out where some glitch is coming from for days on end, not realizing its due to some stuck bits, even though the memory passed POST.

On the other hand, don't buy some name brand RAM from a computer or router maker... Way expensive. I always stay with one of the major name brands, and (knock on wood) been well-off.

Thanks everyone; I've learned some things.

The computer has two slots with a 1 GB capacity. It currently has one 256 MB stick.

I'm thinking of adding a 512 MB stick. In the worst case (incompatibility) I can simply take the old one out and still be better off.

90%+ of computer use is for web and word processing; the only heavy duty application I have is Photoshop. No video editing or games.

That will work (you will have 768mb ), but your computer wont be running in dual channel mode which would be bad. To get dual channel, either get another 256 stick (total of 512)or 3 more 256 sticks, for a total of 1gb. OR ditch your 256 stick and get 2 new 512 sticks.