My i52500k is getting long in the tooth so I'm looking at CPU, motherboard, gpu and RAM. Not to mention Windows 10.
Find a guide specific to your motherboard on how to overclock the i5 2500k. With my EVGA z68 SLI board it was way simple. I've never overclocked anything in my life before this CPU, and was scared to attempt doing so. But - when repalacing a heatsink/fan in my PC I decided I'd give it a shot. @ 4.5ghz on air.. I think my vcore voltage is at like 1.334 or 1.34 (don't take my word for that.. i'd have to check my bios) and I changed like one other setting to lower the heat. Running ram at 1600mhz (did not overclock ram)
Getting my processor above 4ghz was the single largest improvement in frame rates in both DCS and IL-2. Significantly more so than upgrading from a gtx 680 4gb to a gtx 980ti. Perhaps now that I'm running at 3440x1440 resolution I'm benefiting more from that video card upgrade... but the overclock gave this pc I think several more years of life. I believe I'm going to upgrade from 8gb of RAM as well, as IL-2 and DCS both recommend like 12 or 16gb.
Just make sure you follow every step.. and you stress test the machine afterwards with good temperature monitoring software. Make sure you aren't reaching critical temps under a full load, and if you BSOD it probably means slightly more voltage or slightly less cpu speed. Finding the spot between processor speed and heat production is the key. My pc had been throttling my cpu speeds back due to the old fan not working as well anymore and still overclocked ez as pie and stable and strong having replaced that heatsink.
Now in response to the OP - get the best most modern card you can afford imo. It will last you longer. I wish I had waited to get a 1080 rather than buy the 980ti when I did, if nothing else but for future proofing. That being said.. It'll probably be a few years before I feel like I need to upgrade from the 980ti.. but that would be more the case if I had waited for pascal.
Edited by headwarp, 01 March 2017 - 22:56.
Asus Maximus X Hero, i7 8700k @ 4.7ghz, 16gb g.skill Trident Z DDR 4 3200, cheap SSD drives I need to replace with m2 pci-ex4, EVGA 980Ti (to be replaced hopefully with Volta maybe..maybe) Acer Predator x34, MFG Crosswinds, Warthog throttle, MSFFB2, TIR 5