How to determine type of memory installed in computer running Ubuntu

I have an HP Compaq d530 CMT tower computer that was given to me with all components intact except a hard drive. I put a spare hard drive in it and installed Ubuntu 9.04.

This computer is a Pentium IV; i believe the processor speed is 2.8GHz. It has 512MB of RAM in it. I'm thinking about adding some RAM; I might want to try Windows 7 on this computer, probably in a dual-boot configuration with Ubuntu.

I know the computer uses 184-pin DDR memory. crucial.com says it can use either PC2700 or PC3200 and that it can use dual-channel memory. It currently has 2x256MB in it. I'd like to determine whether the existing RAM is PC2700 or PC3200. How can I do that?

 

Get a working OS on the hard drive, take it to crucial and let the site scan your computer. It will tell you what memory is currently installed.
Looking at the specs here:
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=4187643&CatId=2645
it appears that it came with 4 sticks of 128 DDR333 (PC-2700).
Not sure why someone might replace 4 sticks with two and still have 512MB total.
Pull a stick out and post what is printed on it.

 

Well, the hard drive has a working OS on it; it's Ubuntu. But, I don't believe I can run the scanner from crucial.com; it requires DOS or Windows. Anyway, I pulled a memory stick out and see that it's PC 2700. You can see it here or here.

Since original configuration per the link you posted was 4 - 128MB modules, I guess the former owner replaced the 4 with 2 - 256MB modules. Seems strange that they didn't leave 2 of the 128MB modules in, for a total of 768MB.

Per http://h18000.www1.hp.com/products/quickspecs/11632_div/11632_div.HTML, the motherboard supports dual channel memory. I believe that explains why the two DIMMS were installed with one in each bank of two slots. I found very detailed specs at http://h18000.www1.hp.com/products/quickspecs/11632_div/11632_div.HTML

I was thinking I should be able to add 2 - 512MB modules to the current 2 - 256 modules, for a total of 1.5GB, but I'm not clear on whether that configuration works in dual channel mode, assuming the same sized pairs are installed in the right slots. In other words, do all 4 modules need to be the same size? And, do they all need to be the same speed, or can two be one speed and the other two another speed? The detailed reference above says:

Memory
865G chipset
DDR SYNCH DRAM Non-ECC Memory
It is not necessary to add memory in pairs. Memory upgrades are accomplished by adding single or multiple DIMMs of the same or varied sizes. This chart does not represent all possible memory configurations. The Intel 865G chipset supports non-ECC 266MHz (PC2100), 333MHz (PC2700) and 400MHz (PC3200) DDR memory.
For best performance, add in pairs, add in same channel, and do not mix speeds. For dual-channel performance, DIMMs must be same size, same DRAM technology, same DRAM bus width, and either all single-sided or double-sided DIMMs. Brand and timing specs are not an issue. If speeds are mixed, default will default to the slowest DIMM.

 

I'll send Mimsy to have a look; she's the expert on anything related to memory.

 

Aw, thanks plodr... I feel all special and smug now

usafveteran, the easiest way to find out what's in your computer is really to just open it, pull the memory sticks and read the labels. The speed will be printed on them.

When you install four modules in two pairs, one pair can be of PC3200 and the other can be PC2700, but they will run at the PC2700 speed if you install them that way. So like plodr said, if you mix speeds your computer will default to the slowest one, so don't bother buying PC3200 if you have PC2700 installed.

To answer your other question, the four do not need to be of the same size. For dual channel, you need identical pairs only, and they need to be installed in the correct slots for the dual channel feature to be activated. When you open the computer, you'll see that the slots most likely are of different colors, two white and two black, or similar. The colors are the channels, so you should put your two 512MB in one color and your two 256MB in the other color. Put the larges ones close to the CPU, for really optimal performance.

Did that help?

 

Yes, thank you.

 

Thank plodr. I was going to avoid MGs all day today and hang out in my MMO