I built this PC in 2015 and want to improve it on a limited budget. The current hardware is an ASUS Z170-PRO motherboard, an overclocked Intel i5-6600K running at 4.59 GHz, an EVGA GTX 1080 FTW, 32GB of Corsair Vengeance LPX DDR4-2800, a 750W EVGA Gold power supply, a 500GB SATA SSD with a nearly full 100GB operating-system partition, a 2TB NVMe drive for games, and several hard drives for games and Plex media.
I recently bought a used Intel i7-8700K, assuming it would work as a straightforward CPU upgrade, but I now realize that it is not compatible with my motherboard. Would it make sense to buy a used motherboard for the 8700K, or should I sell it and look for a newer used CPU and motherboard combination? I mainly play games at 1080p and would like to run The Witcher 3 next-gen, The Last of Us, and Star Wars Jedi: Survivor. I also use the system as a Plex server. Money is tight after recently having a child, so I'm mainly looking for the best value and would prefer to reuse my RAM, power supply, storage, case, and graphics card if possible.
5 Answers
Before spending money on a motherboard, consider moving the operating system to the 2TB NVMe drive. A 100GB system partition is cramped and can cause headaches, while a clean install or migration to the larger drive will make the system easier to manage. The existing PC is still fairly capable for 1080p gaming, especially with the overclock and GTX 1080.
If compatible motherboards are overpriced, sell the 8700K and wait until you can afford a more meaningful platform upgrade. A used AM4 CPU, motherboard, and possibly a newer processor would let you keep the DDR4 memory, power supply, storage, case, and fans. Buying another old board just to use the 8700K makes sense only if you can find one very cheaply.
There are technically BIOS-mod methods that can make some Z170 boards work with newer Coffee Lake CPUs, using tools such as CoffeeTime and a CH341A programmer. However, this requires careful BIOS flashing and carries a real risk of bricking the board, so a compatible used motherboard is the safer budget option unless you already have experience with this kind of modification.
The least expensive route is probably finding a used B360 or B365 motherboard for the 8700K, ideally for around $40–$50. That would give you more CPU performance without replacing the rest of the system, but keep expectations realistic: the 8700K is still an older processor, so the improvement may not be dramatic in every game.
If the computer is currently working acceptably, there’s no urgent need to upgrade. The GTX 1080 can still handle plenty of 1080p gaming, and replacing several parts at once could cost more than the performance gain is worth. I’d first fix the undersized system partition, sell the incompatible CPU if necessary, and save for a clearly larger upgrade rather than spending heavily on the old platform.
I’d avoid the BIOS-mod route for a daily-use PC unless the board is expendable. Finding a confirmed-compatible B360 or B365 board is much less stressful.