I'm considering replacing my Core i5-4690K with an Intel Core i7-5775C in an existing Z97 system. The build has 32GB of DDR3-1866 memory, an RX 6600 XT, a 512GB SATA SSD, a quality 850W Seasonic power supply, and a large Noctua cooler. The eventual goal is a living-room machine for retro games, light gaming, experimentation, and possibly NAS or temporary storage duties as I add more drives. I'm especially interested in whether the 5775C's 65W rating would meaningfully reduce power consumption. I may also replace the older system SSD and eventually install a different graphics card. Is spending roughly $100–$200 to keep this Z97 platform going worthwhile, or would a newer dedicated NAS platform be more sensible?
3 Answers
Before buying another CPU, tune the existing memory and processor. Faster DDR3 with tighter timings and a sensible overclock can make the 4690K surprisingly competitive, and the difference from a 5775C may be too small to justify the price. I would also avoid paying premium money for a basic SATA SSD; a used enterprise or reputable Samsung, Intel, or Micron drive could be a better option, provided its health is checked. If you need NVMe storage, verify how the motherboard’s M.2 slot shares lanes with the expansion slots before installing it.
For a fun upgrade and tinkering project, the 5775C is interesting, but it is not a major performance improvement over a 4690K or a well-tuned Haswell i7. Its extra cache can help in some workloads, but the lower clock speeds, limited overclocking, and sometimes finicky memory compatibility reduce the benefit. With an RX 6600 XT, either processor can become the limiting factor in some games. Buy it because you enjoy the project, not because it offers a strong value upgrade.
I’d skip the 5775C if the main goal is efficiency. Its 65W TDP does not mean the whole system will use 65W, and idle power with a Z97 board, 32GB of DDR3, an RX 6600 XT, and several drives will still be fairly high. For a NAS, a newer low-power platform would generally be a better investment. For a living-room retro-gaming machine, though, the current system is perfectly usable. The old 850W power supply is high quality, so I would keep it unless it shows instability or has significant age-related issues. Adding drives alone is not a reason to replace it.
The 65W rating was the main reason I was considering the 5775C. I’m hoping to reuse the machine for storage while keeping power draw lower than a typical gaming setup, but I’m also interested in the upgrade as a tinkering project.
The motherboard does have an NVMe slot, but using it would disable one of the wireless expansion options. Since the machine will be near the router, I can use wired networking instead.