i7 4790K @ 4.7Ghz would only be 12-13% faster than an i7 2600K @ 4.8Ghz. I would sell the 2500K and try to find a 2600K that hits 4.7-5Ghz. SB overclocks well and can take a lot of voltage too. Alternatively hunt down a 3770K and overclock it.
^ If that is still not enough, only a 4.8+ Skylake would be a viable upgrade because i7 4770/4790K @ 4.8Ghz is only 15% faster against an i7 SB at the same clocks. The problem is i5 2500K at 4Ghz is clocked low and it doesn't even have HT. That matters a lot in TW3 and GTA V.
If buying an all new platform, at this point might as well go Skylake / 5820K if you don't mind selling all your key platform parts. However, I think selling the 2500K and finding a 2600K/3770K is probably the cheapest and most effective option to get a lot more performance in CPU demanding titles assuming you get one that clocks 4.7Ghz+.
Overclocking your i5 further won't help in terms of CPU usage.
A 5820K at 4.0GHz would eliminate any bottleneck for the next few years. Last I played V my 5930K @ 3.7GHz (too lazy to OC) CPU usage was hitting 6 cores ~45%. Witcher 3 CPU usage also picked up in Novigrad. SNB is old and tired. If you don't want to wait for Christmas and Skylake pick up Haswell-E. Problem solved. I also second 16GB RAM, V and Witcher III both swallowed 5GB roughly after taking away ~1.5GB for 8.1.
It's hard to find a good deal on used SB or newer i7's right now. It's going to be more trouble than it's worth IMO. With Skylake coming, but still 2-3 months away, no one is offloading their i7's right now. OP is sandbagging the CPU by 4-500MHz as it is. Unless the CPU has suddenly turned into a major detriment where his game is unenjoyable, which isn't likely the case, I say push that CPU a bit harder for the next couple months and start with a clean slate with Skylake.
Your CPU should not be a bottleneck at 1440p with a single GPU. Find your CPU's OC limit, and I think you'll be fine.
It's extremely rare that on 1440p the i5 2500K gets bottleneck since that chip can hold very well that resolution. OC it up to 4.5 Ghz, it's 12.5% improvement, so maybe that could solve that bottleneck.To be honest at 1440p I'm surprised it's bottlenecking at my current 4.0. Oh well times are changing.
I've been testing it out a lot in different games lately and seeing CPU usage getting hammered. I'll start with The Witcher 3 where I have 98-99 GPU usage until I enter a city like Novigrad and then my i5 is hitting 100% on 3 out of 4 cores. GPU usage drops and of course FPS follow. In GTA 5, I see very high CPU usage across all cores and when I get up to say 95-98 % CPU usage the GPU usage starts dropping. Note, I can go out in the country with a lot of grass and the CPU usage stays at about 60 to 70% while the GPU usage never drops below 97-98%. And finally Crysis 3 pretty much the same thing as soon as I hit in the 90-100% range on the CPU the GPU usage drops once again. Sounds like it is bottlenecking but I'd like to hear what others have to say.
I realize sometimes in certain games you will always be CPU limited but I have this feeling an i7 with higher ipc would help in the ones I mentioned above.
i5 2500k@4.0 (might try overclocking some more but I'm doubting it will make a difference)
980ti
8gb ram
rez 1440p
Despite conclusive evidence that HT helps gaming significantly now, people are still recommending others to save $100 for a 4690K with no HT and lower stock clocks for some unfathomable reason, for a long lived part that can survive 2 or even 3 GPU cycles.
People are still stuck in 2013 and before where almost all games left virtual cores 5-8 of an i7 idle. It's gamer religion that i5-4690k is the best gaming CPU ever made.
LOL @ the people who think that if a 2500k is bottlenecking performance @ 4.0ghz that somehow overclocking it wont reduce the bottleneck. WUT
Overclock it more.
4.0 is weak for a 2500k. Mine does 4.6ghz with only somewhat more voltage over stock. Mine is an average chip. My buddy's better 2500k he bought in 2011 I overclocked to 4.5 ghz on a 500mV bump over stock w/ Hyper 212 Evo and that overclock has held steady literally since 2011. I have no doubts it could hit 4.7 on more voltage if I spent the time to get it.
If you could hit 4.7-4.8, +700-800 Mhz will certainly be noticeable if you're actually CPU bottlenecking. No doubt
that is simply not always true. my cpu at 2.5 could be completely pegged but at 4.5 not be. very few games go past 4 cores at all anyway.Overclocking your i5 further won't help in terms of CPU usage. You need more cores.
But this info has always stuck in my head. Not sure if it is true anymore after all the BF4 patches, but it is good food for thought.
http://techbuyersguru.com/ochtgaming4.php
Edit: at 1080p / 1200p; the i5's have always been a great balance of price and performance. The popular wisdom being roll that i7 money into a better GPU.
well a 980 ti is TWICE as fast as the 780 ti in this game so of course your gpu is the main limitation by far.I run witcher 3 on my 2500k just fine with a 780ti. Didn't even notice if there was a bottleneck in the processor as it just seems more gpu bottlenecked. My cpu is clocked to 4.5.
Build a skylake build when it comes out. The chips run at 4.2 boost speed out of the box.. should be a decent IPC gain over Sandy. You coughed up over $650 just for a video card... you should be able to afford a new build.
I may do skylake.. may do haswell-e... or wait for skylake-e.. have not decided yet. I don't want to upgrade from 4 cores to 4 cores really... I have no reason to upgrade other than my mother wanting to upgrade from her Q6600 system that used to be mine... I pass down my stuff at a substantial discount when she's ready. I have a 2600K powering my current rig, built soon enough after sandy's launch that I had to send in my motherboard to get the revised versions with different SATA ports.
You DO mean "50 mV," don't you?!?