(solved) Massive performance drop with i7 6700K over i7 2600

[Ewtastic 0]

So i upgraded to i7 6700K from my old Sandy Bridge due to lackluster performance when recording/streaming due to the CPU bottlenecking. I noticed a very nice boost in performance with all games and such, except DiRT Rally, which i have been playing very much lately.

To be more specific it dropped from about 65FPS average smooth @ 2560x1600 on pretty high settings to about 30 FPS and extreme stutter making it unplayable with the i7 6700K. Of course i did a clean install of Windows 7 and all the drivers are installed, everything setup the way it was before, same drivers for graphics card(290X). Everything is connected properly and nothing wrong with the cooling.

Anyone else happend to also get Skylake and notice anything similar? How should i proceed to pinpoint the error here?


Old spec:
Asus P8P67 ws revolution B3
i7 2600 @ 4.2GHz
16GB 1600mHz ram
Asus 290X DCII (running PCIE 2.0)
Asus Xonar Essence STX
Corsair AX1200

new items replacing old:
Asus Maximus VIII Hero Z170
i7 6700K @ 4.2GHz
16GB DDR4 2800mHz ram
Asus 290X DCII (running PCIE 3.0)

Software (both with old and new)
Windows 7 Home Premium 64-bit
Catalyst 15.7.1


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Okay here is whats what
I was running the graphics card in the lowest PCI-E 3.0 slot at 4x for airflow/tight with other PCI-E cards, this did not bottleneck the card however. But it was running on the Z170 chipset instead of the CPUs PCI-E controller/lanes. So the issue would be related to the Z170 chipset itself? I moved the card to the CPU's PCI-E lanes instead and now DiRT Rally runs as it should, even better actually. Altho performance was totally unaffected in everything else i tried so far.