Problems with PC, need some upgrades

[EyelessCrow]

I have an i5 2500k, 8GB ram, a radeon HD 6870, 500GB HDD and a crappy small SSD with my OS on it.

So I built the thing 3 years ago, and I've had some issues, some since I built the damned thing. First off when I start up some games it will minimize and tell me my windows memory is low, I can't figure out why. It may be because I have a small SSD and it's using 8GB page file from that and 8GB page from my HDD but with the bloat from windows that SSD is getting smaller and smaller, so that is one obvious change I need to make is a new SSD, probably a 500GB.

Second issue is I'm pretty sure my GPU is dying. I get some pixel problems in games that sometimes turn into bright green glowing dots/blobs. Usually fixed temporarily by changing a graphics setting and then reverting it back. It's not either of my monitors as I have swapped them out. I will also get some ribbon like things going across my games. ranging from tiny, to what looks like a huge black wall that I pass through. This is what I am mainly looking for help on, with sales this coming week and next week for cyber monday anyone have a suggestion on an affordable GPU? I was debating on getting a ps4 or upgrading my PC and I think I have settled on upgrading. So around 300-350 is what im looking to spend if I need ram and mainly GPU, I might buy an SSD in a month

Also I've never OC'd my i5, I heard it was a really good CPU to OC and shines when you do. Never OC'd anything before but I know I can do it.

[nameeraamer]

update your operating system

[Lathais]

PCPartPicker part list / Price breakdown by merchant

CPU Cooler: be quiet! Dark Rock Pro 3 67.8 CFM Fluid Dynamic Bearing CPU Cooler ($59.90 @ Newegg)
Video Card: Asus Radeon R9 390 8GB Video Card ($274.99 @ Newegg)
Total: $334.89
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-11-25 13:55 EST-0500

That's a great GPU and a CPU Cooler. If you already have an aftermarket cooler you can ignore that. If you don't, you should definitely get one before OCing. There are tons of great guides out there for OCing the 2500K as well.

[EyelessCrow]

Yeah I'm good on cooling, I had the intent of OCing my i5 but never went through with it. I've got watercooling.