Can't decide between 16gb RAM or 8gb RAM?

I am just adding a bit of info to assure you that 8GB is MORE than enough. http://uk.answers.yahoo.com/question/index?qid=20110715122520AAVPwVd shows you I was gaming with my browser and more than a few pc monitors running AND I had Prime 95 running on blend. Prime 95 is used by many to test stability of their overclocked or stock speed computers. It pushes the heck out of your CPU and your RAM when it's on blend. Bioshock 2 with all details on high isn't a lightweight either. I had ZERO issues. 8GB RAM is PLENTY. Looking back I wish I would have also checked on the RAM usage. I guess regardless of the fact that I didn't see the RAM usage numbers I didn't have problems so no worries. 8 will be fine. I was using 8GB of G.Skill 1333MHz CAS 9 RAM.

EDIT: Okay. I went ahead and started Prime 95 on blend(lots of RAM usage), Speccy, CPU Temp, AOL Radio with a few other tabs open including Y.A. of course, had a channel in justin.tv playing on mute and was playing Batman: AC(options maxed out with 32xCSAA) with my task manager's performance monitor running . I ALT+Tab'd out of Batman: AC and the magic number was only 4738MB. Now I will do a bit of recording with fraps.

I am using a 2500K with an EVGA 570 Classified and 8GB RAM.

With Fraps recording and everything else running including Prime 95 on blend the magic number was 4820MB . This is complete overkill. My PC is using more RAM than what your scenario ever could.

Thank you very much for giving me the opportunity to run this little test. It'll help with future questions concerning RAM usage.

8GB is plenty. I don't often have fraps running in the background, but I've never used over 6GB with skype and a game (such as Arkham City) running.

8 gigs will be enough. The number of things that require 16 are minimal, and not in gaming.

Edit: If you have problems doing all that, it won't be due to that amount of RAM.

8GB is more than enough for any gaming and regular multitasking.

Having 16GB is only useful if you're running extremely memory-intensive applications like HD video editing software or AutoCad, Blender, Maya etc.

intel procs can't use more than ddr3-1333 or ddr3-1066 unless you are OC'ing. just because a mobo can do it doesn't mean the proc can. go to the proc mfr's web site and see what speeds it can handle. the amd procs can handle quite high speeds. it's a K processor, so it can OC (overclock).

Considering that you only got two slots and the maximum memory is 32 gb, it is not really about the apps or games but what the motherboard and gpu and cpu require to be at their best performance. The memory speeds that you have are not the same as the specs for that motherboard so they would be incompatible and cause eithe bsod's or not work at all.

If you want best performance then you have to have max memory as per rewquired by the motherboard specs, that is, 32 gb, even though the aps or games only require about 4gb of ram.

Memory Specifications
Max Memory Size (dependent on memory type) - 32 GB
Memory Types - DDR3-1066/1333
# of Memory Channels - 2
(refer first link)

As per BF3, (refer second link) you should check to make sure that your graphics card is suited to the game.

Minimum System Requirements
OS: Windows Vista (Service Pack 2) 32-Bit
Processor: 2 GHz Dual Core (Core 2 Duo 2.4 GHZ or Althon X2 2.7 GHz)
Memory: 2 GB
Hard Drive: 20 GB
Graphics Card (AMD): DirectX 10.1 compatible with 512 MB RAM (ATI RADEON 3000, 4000, 5000 OR 6000 series, with ATI RADEON 3870 or higher performance)
Graphics Card (NVIDIA): DirectX 10.0 compatible with 512 MB RAM (NVIDIA GEFORCE 8, 9, 200, 300, 400 OR 500 series with NVIDIA GEFORCE 8800 GT or higher performance)
Sound card : DirectX compatible
Keyboard and Mouse
DVD ROM Drive

Recommended System Requirements
OS: Windows 7 64-Bit
Processor: Quad-Core CPU
Memory: 4 GB
Hard Drive: 20 GB
Graphics Card: DirectX 11 compatible with 1024 MB RAM (NVIDIA GEFORCE GTX 560 or ATI RADEON 6950)
Sound Card: DirectX compatible
Keyboard and Mouse
DVD ROM Drive

Better get the 16. 8 might just be a little too short. Yeah u lose MHz but u won't waste money buying both

You will need at least 32GB of RAM to launch Battlefield 3, but don't worry too much about memory - you can always download as much as you need later on.