PC3200 is not compatible with all systems, so be careful! You should check out your machine before spending time or money on this. I have had machines come to me with major problems from mixing the RAM. There is several different types of ram, because it depends on your system.
As for speed, you can gain some and improve stability by having the correct vitural memory settings. Here is a section from my lockdown page:
"» Now Let's move on to the virtual memory setting. Open the 'control panel' and click on "system." On this page, in the bottom right corner, you will see the amount of ram memory you have installed. Your virtual memory should be twice the amount of ram. Because some of your ram will be in use, you will need to round up to the closest number shown in the chart below. Write this number down and move on to the next paragraph.
Virtual Memory Chart:
Any number up to, but not over 256mb ram = 512mb virtual.
Any number above 256, but not over 512 ram = 1024mb virtual.
Any number above 512, but not over 768 ram = 1536mb virtual.
If you have a number higher than 768 listed for your ram, then you should still set your virtual memory to 1536mb. This equals 1.5gb and your machine will work very well with this. However, many computer makers do not want virtual memory set higher than 1.5gb.
Now that we have your proper number wrote down, lets change the setting. With "system" open, click on "advanced" and then "performance settings" Now "advanced" and then "virtual memory / change." Select "custom size" and then type the number you wrote down (it should be either 512, 1024 or 1536mb) into both boxes and then click "set." And then click "OK" and then "OK" and then "apply."
Finally you will need to "restart" your machine."
Hope this offers some help to you.