Which to get: DDR3 or DDR2?

Whats the real difference? I notice that DDR2 RAM has a much low cas latency compared to DDR3, but what more do you get with DDR3? I'm debating on what to get for my gaming rig build and I can get a great price on some DDR2, but would this not be ideal for gaming?

From my experience and the tests that I've seen, memory speed makes very little difference in real-world performance.. especially in gaming. However, you can get a socket AM3 motherboard and 4GB of DDR3 RAM for about $150 now, so I don't think it makes alot of sense to go DDR2 anymore. All the newest Intel platforms use DDR3. But for all intents and purposes, someone who has the same CPU as me (Phenom II X4 955 @ 3.7ghz), but on a Socket AM2+ platform w/DDR2 RAM will get the same performance as me. There may be a 2-5% difference in some games. That's really about it. I know they made some LGA 775 motherboards that supported DDR3 as well, but they didn't offer any noticeable performance gains over the same basic system with DDR2.

DDR3 runs at a faster frequency than DDR2, but with higher latencies. Overall, DDR3 is faster in most tasks. The higher frequencies more than make up for the latency increase in the vast majority of apps.

For building a new gaming rig, I'd go with a setup that has the best upgrade path. If you buy an AM2+ motherboard and DDR2 RAM, you may be limiting your upgrade path when AMD comes out with new CPUs. They may only work with socket AM3 boards. The only commonly-sold Intel platform that uses DDR2 is LGA 775, which to my knowledge isn't going to have any new CPUs made for it. So you would really have no upgrade path. It's not so much the memory speed and performance that should make you get DDR3, it's the long-term viability of the platforms that it works on.

Go for DDR3.

go for ddr 3 if you can afford it. They say it runs faster, and consumes less power than ddr2, and probably has better overclocking and timing ability.