Question DX4860 - 8GB Memory can't work

[Updx4860]

I want to upgrade memory and other hardware for my DX4860-UR28 desktop. Here is the current configuration:

Desktop = DX4860
CPU = Intel Core i5-3330
Existing memory = 2 x 4GB DDR3 (per CPU-Z it is 800 MHz), while the part number says it is 1600MHz PC3-12800)
Motherboard = Gateway IPISB-VR
GPU = Intel HD Graphics Card
OS = Windows 10 64bit

I have already replaced storage with SSD.

I just bought 2 x 8GB DDR3 1600MHz PC3L-12800R for my computer but I get nonstop beeps (with no breaks) when I install the RAM either in combination or alone with the existing memory. I can't get to the CMOS setup. I was wondering is it a compatibility issue or there is a limitation on the max memory per slot.

I am also planning to upgrade the CPU to intel i7-3770. Ebay seems to have few cheap used options <$100. Do I need to watch out for anything buying the old processor from ebay?

Any recommendations for upgrading the GPU. I run three monitors with multiple data stream for trading, I am planning to add more monitors.

Thanks for the help!

 

[rgd1101]

pc3l might mean low power DDR3L(1.35V). get one with DDR3(1.5V)

 

[Calvin7]

acer ipisb-vr rev 1.01 mainboard specs

Memory

4 x 240-pin DDR3 DIMM slots – Dual Channel DDR3 1333 non-ECC, un-buffered memory (Max 16GB)

Looks like memory you bought is not supported - (1600MHz).