RAM defraggers are a waste of time - you're just sitting there paging everything out of RAM to the HD (takes a very long time) so stuff paged to the HD can be paged back into RAM neatly (takes another very long time). Plus they do nothing about freeing leaked memory, they just move it to the HD where it's still sitting there doing nothing You'd be better off looking at the real bottleneck causing the slowness i.e. the HD, which is orders of magnitude slower than RAM due to mechanical moving parts in it RAM is so fast you're not going to physically see any difference in speed yourself, however "fragmented" allocated memory gets if it's all in RAM already