I recently had heat spike issues on my PC and through process of elimination realized my Corsair H100 v2 AIO was going bad. While waiting for the advanced RMA to arrive, I de-clocked my i7-7700k back to stock 4.2, turned off all turbo, set avx offset to -2 and set my RAM to 2166. This kept my heat well in check until I could get everything fixed.
I originally thought the heat issue might be due to needing to replace the liquid metal after hearing some people say it might need to be replaced after a year or so.
Due to that, I ended up buying the custom copper IHS from rockit cool thats 15% larger, so I went ahead and re-did the delidding/relidding process again to replace the IHS. Here are my specs for reference, when overclocked:
CPU: i7-7700k de-lidded, Conductonaut Liquid metal on die and IHS
Custom all copper, 15% larger IHS (lid) from Rockit cool
Kryonaut thermal grease
Overclocked to 5.0 GHz on all 4 cores at 1.36v
Stock ring speed - set to auto.
Cooler: Recently RMA'd and replaced Corsair H100v2 AIO on front of case
Using 2 fans it came with in push + 2 Corsair Maglev ML 120s in Pull for 4 fan push/pull
Case: Corsair Carbide Series

Clear 600C Inverse ATX Full-Tower Case
Upside down, PSU at the top
2 x 140mm Corsair fans on the bottom for intake + 1 x 140mm on back for exhaust
All fans set to DC at 100%
Ram: Patriot Viper 2x8GB Kit DDR4 (PC4-29800 - 3733MHz)
GPU: Aorus 1080ti with fans set to 85%
PSU: Corsair RM1000i with fan set to 100% as an extra exhaust fan (PSU on the top of case)
HDs: Samsung EVO 960 NVMe M.2 1TB - Samsung 840 Pro 256GB SSD
Mobo: MSI Z270 Gaming M5 Motherboard
I noticed that with everything overclocked, but my RAM set to 2166 I was getting a maximum of 70c in Prime95 Blend and FFT tests, I would idle in the high 20s to low 30s and in Battlefield 1 (the most CPU intensive game ive played) I was in the 50s, with rare spikes in the lower 60s.
Once I upped the speed of my RAM, which is only stable at 3333 MHz, my heat in Prime95 jumped to 82c. My idle was now in the high 30s to mid 40s and BF1 ran in the 70s with spikes to 80c. I posted this fact in another thread and a very kind user led me here to this thread.
My RAM (which I just contacted Patriot customer support and RMA about) kind of sucks. XMP2.0 never worked. I wouldn't boot with it set manually to 3733 and at 3600 and 3466 it would boot but give immediate rounding errors in Prime95 even with stock bios settings and CPU clock speeds. At 3333 its stable both at standard CPU clocks and my overclock to 5.0 GHz. However, with auto voltage and timings, it runs at 1.376v and the timings are very slightly off. It will NOT run at 1.35v without rounding errors, even at slower speeds. I assumed the heat issue was just another problem with the RAM.
I went into BIOS and changed my PLL OC Voltage from Auto (which did not display an actual value) to the default 1.2v. I am now fully overclocked back to 5.0 GHz at 1.36v (which admittedly is auto and can drop a bit) and my RAM is stable at 3333 MHz at 1.376v (auto again.) Yet my temps are now IDENTICAL to what they were with the RAM at 2166 and 1.20v.
I see here on overclock as well as on Intel and MSI forums, no one ever got to the bottom of this with an actual answer. I figure 1.2v default can't hurt and my temps with it at Auto were still acceptable anyway. Worst case scenario I have issues with my AIO again and my real temps are 10c above whats reported, but honestly, that sounds illogical IMHO.
Has anyone gotten any further with this? Also, is it worth going through with the RMA on the RAM to try and get 3733 or more of a waste of time? I am wondering if the RAM speed issues and XMP2.0 not working is actually due to the MSI z270 Gaming M5. Have people with this board had issues with RAM speeds and XMP, or simply issues with PLL OC Voltage? I was going to use Corsair Vengeance 3600 but it was out of stock and I didn't want to wait... Funny enough, I had the same issue with the MOBO I wanted, so I settled for this one as I have always had good luck with Overclocking on MSI boards in the past. Patience is not my forte lol... id rather run down to our enourmous Frys Electronics and buy everything than wait for delivery lol.
Thanks!