I have a Hp 630 laptop. 2 DIMMs and 2GB(1066 Mhz) of ram on one slot. I want to upgrade it.
At this point I have two solutions:
- upgrade to 4gb (2x2 Gb)
- upgrade to 6gb (1x2 Gb + 1x4 Gb)
Which one is better?
Performance advantage of dual-channel configurations is negligible in most workloads -- on the order of 1 to 5 percent. (See, for example, http://www.tomshardware.com/reviews/PARALLEL-PROCESSING,1705-11.html.)
Once you hit swap, however, you will be penalized by orders of magnitude. 100 MB/s vs 8000 MB/s. I would always choose more RAM.
2x2GB will allow your system to work in full dual-channel mode, which means that memory transfers will be faster.
Depending on your processor you may be able to use a hybrid dual channel mode (on Intel i-series processors) which gives the best of both worlds, but means that above 4GB of used RAM you will not see the speed benefit of dual channel.I do not know if AMD processors support this extra mode
If you often find yourself running out of RAM then the 6GB configuration may be better for you, if not then the dual-channel mode will give better performance.