Windows 7 Ultimate x64 Upgraded RAM from 4gb to 8gb. Seems slower.

I recently bought a 4gb stick of RAM. and installed it onto my Aspire X3950 Motherboard. The two previous sticks are "GU512303EP0202 Unifosa 2GB GDDR3-1333 DIMM RAM Memory" and the are installed in the 2 slots of the 'white' channel. The new 'third' stick I just installed is "PNY Optima 4GB 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) Desktop Memory Model MD4096SD3-1333", and it is installed in the the first slot of the 'black' channel. They are identical in every aspect as far as I can tell. My computer seems to be running slower than usual. It will lag at times I've never experienced lag before. I've tried looking around the forums, and can not figure out what to do with my particular situation. ANY help would be greatly appreciated :)

First 2x2GB RAM

Unifosa Corp. - News

4GB RAM

https://pny.com/4GB_PC3-10666_1333_M...MD4096SD3-1333

Never really a great idea to mix different size RAM modules and also run them in both dual channel and single channel at the same time. Don't know what your motherboard specs are but for 8GB you'll be better off either buying another identical 4GB RAM module or 2 extra identical 2GB modules which will then enable it to run at the full dual channel mode and use only the 2x4GB or the 4x2GB

Yeah, I kinda figured that might be the case. I asked the guy at geek squad in best buy and he said it doesn't make a difference. Shows what they know.. So, if I get another 4gb module, would it be better to do them both on the white channel, or one on each?

Does the lag go away if you remove the new RAM?

Offhand, my first inclination is that there may well be other reasons for the lagging--unrelated to RAM.

You say "seems to be running slower than usual". Can you clarify what you mean be "seems"? Is it slower in all operations? Slower to boot? Slower to go to a random web site? Slower to open a big application? Slower to run a full disc scan?

Do you have any reason to believe you ever used all of the previous 4 GB of RAM? Exactly how did you expect to notice that you had installed more RAM?

The differences between single and dual channel are marginal and may not be noticed at all. You're certainly better off with 8 GB in single channel than 4 GB in dual channel IF repeat IF you in fact regularly use more than 4 GB.

Well, it just seemed to lag on everything you mentioned. Programs became unresponsive. Just updated my chipset driver and everything seems to running very smoothly now :) Thanks for your advice and interest everyone.