Question about PC RAM.

[ral-clan]

I am pretty new to modern PCs. I have a slightly older PC (IBM Thinkcentre 8187) with 1GB RAM inside. It has two empty memory module slots so I'd like to add just a little bit more memory. Apparently I need memory modules like this:

333Mhz 184-pin PC2700 DIMMs, SDRAM

Furthermore, my computer is dual core, so apparently I need to balance the RAM in the two slots (always buy memory modules in matched pairs).

So, being cheap, and not needing much more RAM, I was thinking of either getting two 256MB modules, or two 512MB modules.

Online, I can find TONS of sites offering new and used 333MHz 184-pin DIMMs. That is if I omit the "SDRAM" keyword from the search.

If I add "SDRAM" to the search specification, the results are reduced by a lot.

Is that because there ARE such things as non-SDRAM modules? Or is it just a case of the product description neglecting to mention the SDRAM part, but it really is SDRAM.

For example, on the site TigerDirect.ca I can find ONLY this product if I search for "DDR PC2700 SDRAM":
http://www.tigerdirect.ca/applications/ ... DR%20SDRAM

...and that's it. That's the ONLY matching product that has "SDRAM" included in its description.

But if I omit the "SDRAM" keyword from the search, I get tons more products:

http://www.tigerdirect.ca/applications/ ... mage12.y=0

So, does it really matter if I see SDRAM in the product description or not? Perhaps all PC2700 DDR RAM is SDRAM by default? No?

Any help is appreciated.

Oh, and if anyone has modules like this for sale, please PM me. Thanks.

[carlsson]

I am fairly confident all PC2700 memory are the same, give or take such features like CAS latency (CL2, CL3) and possible ECC mode.

Besides, the last PC architecture I know about that required you to install memory in identical pairs was the first generation Pentiums c:a 66-200 MHz, those with SIMM slots. Since SDRAM, DDR and so on came onto the market, it doesn't apply anymore unless your PC or motherboard says otherwise.

You wrote your CPU is dual core. Perhaps check the motherboard if it takes either DDR or DDR2 memory. While usually it is not possible to mix them, you may find cheaper and bigger DDR2 memory modules than you will find of the slightly older type. Believe it or not, but I think for PC2700 your best buy is someone on eBay. Some sell supposedly unused modules, others sell 2nd hand. Or maybe someone here has spare memory modules to offer, like 1-2 loose common VIC-20 cartridges for one 512M memory module.

[ral-clan]

The manual only mentions DDR memory. It is possible that the computer can accept DDR2 memory, but the manual was printed at a time before DDR2 memory existed, so I don't know. All I know for sure is that DDR memory will work fine.

As for memory in pairs: yes, my computer CAN accept single DIMMs, but in order for the "multithreading/hyperthreading" dual core functionality, the memory must apparently be the same in slots 1 & 3 or 2 & 4. Right now I have two 512MB modules in slots 1 & 3, so I'd like to fill slots 2 & 4.

Yes, I have a lot of spare cartridges for the VIC, Atari 2600, ColecoVision and Intellivision. I would be willing to trade a couple of cartridges for a couple of RAM modules - if anyone has any to trade.

[vic user]

i have quite a bit of RAM modules, and thus i will get them out for you when you come over next week.

[Ian Colquhoun]

Here is a good start to answer all your questions. If your MB accepts DDR memory, I find it unlikely that it would accept DDR2 memory as well, since according to the third paragraph of this link details that DDR and DDR2 are assembled in different packages, TSSOP and BGA respectively.

As far as interchanging, it looks like you could use PC-3200 modules instead of PC-2700 and suffer no performance degradation, but going lower wouldn't be a good idea.

[Boray]

http://www.orcalogic.co.uk/asp/prodtype ... rchFor=all

http://www.crucial.com/kb/answer.aspx?qid=4081

[carlsson]

True, DDR2 modules won't fit physically into a DDR slot. I wonder if the latency will be a matter to you when you put the memory in pairs with the existing one. Another thing you'd have to look up or empirically try is whether your motherboard accepts both single and double sided modules; that is it has memory chips on both sides. Some boards may require it either way while on others it doesn't matter.

[Boray]

I don't think the dual channel mode has anything to do with dual core processors?
http://en.wikipedia.org/wiki/Dual-channel_architecture

My PC is a single core machine but has the ram slots color coded in pairs.

[ral-clan]

A store only a couple of blocks from me has a matched pair of used 256MB modules for $10 each.

Sounds like I might give them a try.