You guys are making me wonder if a Xeon is still a better option for me. I still have my X58 stuff installed and could return the 4790K. I wanted a Haswell for emulators and VMs though, which are largely dependent on single threaded performance and Haswell is said to be particularly good with, as well as the lower power usage. The Xeon's 6 cores would be better for compute and data science work I do though.
However, if I don't upgrade the platform now, I probably will end up not doing so for years, and will be stuck with the slower USB, SATA and PCIE. It took a lot of work to find a Z97 board that fit all my requirements, and even the one I chose (MSI G55 SLI) is apparently discontinued. I got an open box one at Microcenter for dirt cheap.
No no
Keep the haswell.
There are emulators that specifically take advantage of avx2. Not sure how much it changes the experience through, surely its playable on the older instruction sets.
I really never planned to go this route at all. I had no idea the xeons got so cheap and my plan since ivy launched was to ride this 920 until haswellE. I thought I would suffer but honestly, haswell launched and i expected more. But regardless, my eye was on the 5820k\ddr4 and I was waiting for it. About the time haswellE launched my wife and I started looking into buying a house. We started crunching numbers and realized the substantial difference a large down payment would make. And the 5820 was clocked so feakn low, once again I expected more. I wanted one but I hesitated for those reasons.
I had heard people suggest Xeon ep for my motherboard and never paid it much mind. Only recently, when i seen the undeniably crazy low prices have I started crunching the performance numbers. The 4790k is faster than an x5670, it will take overclocking the Xeon towards 5ghz to match the 4790k and even then it won't surpass the haswell. There will be apps the Xeon wins and apps it looses. The single thread of a 4790k should still be stronger for sure. But these xeons close to 5ghz should be at least as strong as the 4770k stock. Or rather close.
Intel has made improvements. Haswell is much more sophisticated and just manages to handle data much better. Its memory systems are so good that the Haswell dual channel is more efficient than the x58 triple. Haswell handles data better, better more effective caching, the latest instruction sets, its better at keeping the cores fed. There are a lot of improvements.
So much that a 6core and 12thread westmereEP will struggle to keep up with a 4790 no matter how high you can overclocked it.
So your haswell is the better platform, no contest.
But for someone with an x58, the westmereEP is a massive upgrade. Overclocking it makes the 6 year old platform at least relevant today. You are talking 40-50% overclocked here and CPUs simply haven't advance all that much since westmere launched.
Just because u can catch up some with westmereEP doesn't make it a better option, not at all. There are trade offs for sure. The performance for OC x5670 is strong but haswell has many improvements that can make it impossible for the older 12thread to touch. There are a lot of benchmarks that take specific advantage of these new features. But luckily for the westmereEP, not so much in the real world apps.....especially in gaming.
WestmereEP is a great option for me. Heck, I find myself less and less on my PC. I buy so many games and never even play them. I absolutely love PC and watching the tech evolove. But PC gaming is becoming more of a dream if mine than a reality. My 7yr old son is on my PC 10x as much as me. So especially for me, westmereEP is a great option.
Oh,
And just for the record, I am an old school PC kind of guy. Back in the day, buying celerons and durons then overclocking the snot out of them. Those were the days. And honestly, that's probably more to do with my enthusiasm than anything else. It kinda reminds me of the old days......days I am so fond of