Needing Instructions for Upgrading DDR RAM

Dear GMartin,

You need to first see what your motherboard would accept .. What frequency of RAM it would accept .
Check the motherboard manual

Thanks,
Sunray

Also see that you have extra slot in your motherboard ( ie near your existing RAM) .. for putting additional RAM
or if you have 64 mb RAM now you can replace that with 128 or more ..

Sunray

You can't, however, put a slower speed in than the cpu's bus is running at (ie:  if the cpu is an Athlon Barton @ 166MHz or 333MHz CPU speed, and he currently has PC2700 (333MHz) DDR, you cannot put PC2100 (266MHz) RAM into it.

btw, if you don't have sandra, you can d/l it here.  http://www.sisoftware.co.uk/dload/sware_figure.php?&a=&langx=en

It will tell you the make/model of motherboard (if it's recent enough it should) as well as exact specs on the RAM.

Let us know if you have more questions.

BTW sunray, nobody makes or has ever made (to the best of my knowledge) 64Mb of DDR RAM.  It's usually been 128Mb and up.

OK, apparantly a few manufacturers have made some, HP used it for a while, but I haven't seen any 64Mb DIMMS of DDR anywhere in the last 2 years...

Hi Everyone:

       When using the software sandra, where should I go to determine the frequency of the motherboard?  And, secondly, when purchasing the DDR RAM, should I consider matching the frequency of the motherboard to the frequency of the RAM?  

       Thank you

       George

When using Sandra click on 'CPU & Bios information' to get the FSB of the cpu.  And yes, you want to match the FSB of the cpu with the fsb of the RAM for best performance.

Keep in mind Sandra may not tell you exactly what you're looking for, you may have to do some figuring of things out.  for instance, on my P4 1.6 laptop it says

Processor
Model : Intel(R) Pentium(R) 4 Mobile CPU 1.60GHz
Speed : 1.60GHz
Performance Rating : PR1758 (estimated)
Type : Mobile
Package : µFCPGA Mobile
Rated Speed/FSB : 1600MHz / 4x 100MHz

Yet obviously 4 x 100 isn't 1600...  it's a 400MHz cpu FSB, it's just quad pumped.

If you're not sure, let us know what it says and we can tell you what it means.

Also, if you click on 'System Summary' and run that information module, you'll get similar information.  Here's a 'snippet' of what my laptop shows.  I'm just showing the info under 'chipset 1'

 Chipset 1
 Model : Intel Corporation 82845MP Brookdale Host-Hub Interface Bridge (B0-step)
 Front Side Bus Speed : 4x 100MHz (400MHz data rate)
 Total Memory : 256MB DDR-SDRAM
 Memory Bus Speed : 2x 133MHz (266MHz data rate)

So you see here my intel is running a 400MHz cpu FSB data rate, and a 266MHz memory bus data rate.  

If you have an AMD system, however, you get MUCH better performance running those two synchronously.  ie: at the same MHz 'data rate'

You can also get alot of that information of the 'motherboard' information module.

Interestingly enough I find different info under my intel cpu laptop in different modules than I find with my Athlon XP desktop, and they run the same version of sandra.  

Hi

       Thanks so much for the prompt replies.  After reviewing some deals on DDR RAM at Pricewatch.com, I noticed there are different numbers for DDR RAM.  For instance, I noticed a few PC3500, PC3000, etc.  What exactly do these numbers suggest?  
Is it referring to the frequency of the RAM?  And, if it does, I am not sure I understand.  

       Any more follow ups will be greatly appreciated.  

      Thank you.

      George

These refer to the speed, in overall GB/s of bandwidth

PC3500 has a theoretical bandwidth of 3.5Gb/s
PC3000 has a theoretical bandwidth of 3.0GB/s
PC2100 has a theoretical bandwidth of 2.1GB/s

And so on.

http://www.kingston.com/newtech/ddrbandwidth.asp has some good info on it.

BTW, technically there is no such thing (yet) as PC3500, because it's not jedec certified.  PC3200 is the fastest specification jedec has adopted.

Manufacturers still sell PC3500, and even PC4000 because they have faster modules, although not adopted by the jedec specification, and want to keep the naming convention.

For instance, on the kingston page I linked to if you look at the bottom you'll see it goes from PC2700 to PC3200 to "434Mhz DDR".   This is because PC3500, which operates at 433/434MHz hasn't been adopted as an intl. standard yet, and so kingston calls it what it really should be called.

Hope that helps.

BTW the reason DDR is listed by GB/s bandwidth and SDR is listed by bus speed is so you can easily differentiate the two types of SDRAM.

Both DDR (Double Data Rate) and SDR (Single Data Rate) are still SDRAM (Syncronous Dynamic Random Access Memory)

Hope that helps.  If it's too much or you need more detail or more explanation, let me know.

Short answer> they should be matched
Try to find an identical dimm
If you can't, get a dimm with the same specifications, i.e.  ddrxxx

Hi Everyone:

        Thanks for the follow ups.  I especially appreciated Alberta's extra tips and explanations to help me make sense out of the technical specifications of DDR RAM.  

        George