dell dimension 4600

I have 4 sticks of pc2700 256mb of ram , would it be worth the money to get two sticks of 512 mb400 pc3200. would i get better performance thanks.

It depends on how cheap you can get the pc3200 for, and if you are sure your motherboard and bios support the faster memory. Faster memory is always a good thing, as long as other parts of your system aren't holding it back.

2 sticks of 512 value select corsair $82 and my dell book says it can use pc3200,

I would google some articles on memory speeds and focus on your processor (2.8ghz or whatever), and see what actual differences in speed they show. There are numerous articles on memory speed. Some setups will benefit quite a bit, and some will not. For example: I have 2 systems. One with 3.2ghz processor and 2gb of pc533 dual channel, and one with 3.4ghz proc, and 1 gb of pc533. I do extensive photo and video editing. I can tell virtually no difference between the two, but if I ran benchmark tests, I'm sure that there would be some difference. Most benchmark tests show differences in thousanths of a second or milliseconds. That is not something that you can really see and measure with your eyes. Now going from a 2.8ghz system to a 3.2ghz system, there is a noticable difference. I would look at spending that money on a faster processor first, then maybe later upgrade memory. Or get a motherboard and bios that will allow a slight overclock and you would be better off as far as noticable speed difference. Another help to noticable speed, is putting a 10000rpm hd as your primary drive. Speeds up boot time and access times.

I don't think you'll see much difference. That money can be better spent (on your new system?).