Advice on buying more memory

[rw120555]

I've never bought and installed additional memory before, but with prices so low I think I am going to. A few Qs:

* Is there a utility that will tell me exactly what kind of memory I have and should get, e.g. is my memory parity or non-parity, PC100 or PC133 or whatever, how many banks are free, what the maximum size of a module should be? Or do I just open up the box or try to check the system specs to figure this out?

* Any recommended vendors? Crucial.com seems to have really good prices now.

* Even if a module says it is for a specific machine, will it generally work ok in another machine that uses the same type of memory? Are modules listed as being for a particular machine really different, or is such labelling just a convenience so you'll know the memory will work in your machine?

* What is ECC registered, and why does it cost so much more than plain old ECC?

Thanks much. RW

 

[IamDavid]

1.) Not sure what its called but yes.

2.)Crucial.com is my favorite, others like Mushkin.

3.)Yes most RAM will be changeable between systems. Some generic won't so check with the vendor.

4.) What is ECC RAM.

 

[Jiggz]

Your best source of info about what type, speed or ECC/Non ECC memory goes on your system is the mobo manual. If you do not have one try searching on the internet for the manufacturer's homepage they usually have them for download. Then you can go to Crucial and use their memroy configurator. Then your all set.

 

[rw120555]

The docs for my system configuration say

DIMM 1 19416 DIMM,128,100M,16X72,4K,168

So, I think this means 1 128MB Dimm, PC100. Does this also tell me parity/nonparity and whether or not it is ECC? I assume 168 means 168 pins, but what does 16X72 and 4K stand for? Thanks.

 

[kylef]

Hmmm... the 72 in the 16x72 makes me think that youre DIMM is ECC, which is fairly rare. Registered memory is even MORE rare, and won't work on most consumer motherboards, so I think you should avoid registered memory.

Basically, if you get ECC memory, it will work in a non-ECC configuration. So, for instance, if you get a stick from Crucial, it might be worth spending the extra $4 or whatever to get ECC... It will work even if it turns out that your chip is NOT ECC (although I'm pretty sure it is).

As to your other questions, I think the 4k is the refresh rate, but that shouldn't be an issue with DIMMs. The 100M is, as you guessed, probably referring to the 100 Mhz SDRAM speed. The 168 means it's a 168-pin DIMM.

There's a shareware utility called SiSoft Sandra that can tell you more about the kind of memory you have installed. You can download it at CNet.

 

[rw120555]

Thanks everybody! I finally hunted down Dell's docs on my system (an Optiplex GX1) and it says the memory is "64-bit (non-ECC) or 72-bit (ECC), noninterleaved". Also, it is indeed PC100. I also have an Optiplex GX1P, and it is only 72-bit ECC.

So, I've gone to Crucial and ordered a 256MB, SDRAM, PC133, CL=2, ECC Dimm for $52.19. I could have saved $2.70 by getting PC100, and a few dollars more by taking a chance on non-parity, but it sounds like this is safest and has the best chance of working on a different machine if I ever decide to use it somewhere else.

I'm amazed at how cheap this is, and Crucial appears cheaper than most of the competition. That actually makes me a little suspicious, but I've heard good things about Crucial here and elsewhere so hopefully all will be ok. If I see noticeable improvements in performance, I'll be tempted to add more memory to some other machines. Just wish the pc800 rdram prices were more in this range, since that is what my machine at work will have. Crucial doesn't appear to sell that memory though.

 

[crzyc]

crucial is great memory

try muskin.com for rdram

 

[rw120555]

Thanks crycz. Looks like Crucial has better prices than Mushkin on PC100/133 memory; and Kingston looks better on PC800. I'll check all three of these places next time I am buying. RW