I'm using 8gb ddr3-1600mhz non ECC on my LGA 2011 Xeon E5-2670 gaming rig and it is plenty for my light editing and gaming needs, haven't run into any memory issues yet.
I've tried 16gb on Adobe Afther Effects and that reduced my rendering times by half, but other than that I still think 8gb is plenty for most of my daily needs.
My secunday gaming pc that I use for streaming it uses an AMD FX8350 with the same amount: 8gb ddr3-1600mhz, no issues whatsoever streaming at 720p.
MOBO - Asus P8P67 Deluxe
RAM - Corsair Domminator DDR3 2000mhz 3x2GB -6GB Total
CPU - 2600k @ 4.6ghz with Corsair H100 water cooling
GFX - Zotac AMP GTX 680 - Stock
SSD - OCZ Agility 3 - 2x 128GB - RAID 0
POWER - 850w Thermaltake - don't remember the model
SCREEN - Samsung Syncmaster S27A950 D 120hz - 27"
This PC is abit old school now but it gets the job done nicely still , however I do have some issues with some games and apps using up all the 6gb of ram and then having to use my SSD's pagefile. I never had any issues with ram untill about a year ago, when I in counted GTA IV + mods & Skyrim + Mods, after that it was AC: UNITY and some other games. I was also having problems opening 100mb+ PDF's for work, Ive had this PC for about 4 years now, so I got my moneys worth.
MOBO - Asus X99-A
RAM - G.Skill Ripjaws DDR4 - 2400mhz 4x4GB - 16GB Total
CPU - 5930k @ 4.6ghz with NZXT Kraken water cooling
GFX - Zotac AMP GTX 980 Extreme Ed
SSD - Samsung - 2x 256 PRO - RAID 0
Power - Corsair AX Platinum 850w
SCREEN - Asus ROG Swift G-Sync 144hz - 27"
My new PC is simply a BEAST. BUT! ive have had some problems with mobo BIOS and booting, but apart from that I cant see my self buying a new PC for at least another 3-4 years.
Unless you use photo editing software, video editing software or something that uses missives amounts of ram and data. So having more 16gb+ for your every day gamer - office worker is complete overkill.
I wonder how much performance difference would be if you put that GTX 980 to your 2600k at 4.6ghz,
would it perform the same as the 5930k 4.6ghz on games?
I'm just saying this because if you got the new pc only for gaming, I think it may have been not the best choice as the old one was beefy enough.