To expand a little on the question of RAM GBs, Most applications won't use 4 GB of RAM. Intensive graphic applications (Corel Draw, Adobe Illustrator,etc...) and video editing may use more. The majority of users won't see a difference between 4GB and 4GB+.
As to DDR2 vs. DDR3, look at this:
Contrary to popular myth, CAS 2 @ DDR-400 is identical to CAS 2.5 @ DDR-500 in terms of latency. A quick rule of them for judging latencies is as follows;
CAS 2 DDR-400 = 10ns
CAS 2.5 DDR-500 = 10ns
CAS 4 DDR2-800 = 10ns
CAS 5 DDR2-1000 = 10ns
CAS 6 DDR2-1200 = 10ns
CAS 7 DDR3-1400 = 10ns
CAS 8 DDR3-1600 = 10ns
All of the above are identical in terms of latency. The same method can be used to compare other latencies as well.
The difference between AMD and Intel in terms of memory performance:
The common wisdom is that “Intel loves bandwidth and AMD loves low timings.” The reason this is the case has to do with two different approaches in handling memory.
Intel uses an offshore memory controller in the northbridge that runs at a much slower speed than the CPU. What this allows Intel to do is incorporate very large L2 and L3 caches onto the CPU. L2 and L3 caches have an order of magnitude better latency than RAM memory does, so as long as these caches can be fed, the latency of RAM can be effectively hidden. Once a cache is exhausted however, the latencies are felt force. The higher the bandwidth of the RAM, the better the caches can be kept filled.
AMD sacrifices cache sizes for an integrated memory controller that runs at the speed of the CPU. What this means is, the caches will empty quicker, but once they do, the overall performance will not be affected as much.
In short, the Intel architecture is fastest for read accesses that fit in the large cache, but slower for more intensive applications that may exhaust the cache’s resources, while AMD sacrifices cache performance for overall memory performance.http://forums.extremeoverclocking.co...d.php?t=286070
So, if you can run DDR2 cas5 at 1200 MHz, it will be quicker than DDR3 cas 8 at 1600 MHz.Edited by 18 is # 1 - 6/18/09 at 7:40am