CPU Power Levels

[Enquiries]

Hi Eddie and Robbie,
I've decided I want to build my own NAS as my qnap TS251 is just too slow. I've decided on Intel for the transcoding (I use plex) and was considering the i7 265k or the i5 235 which are around the same price. Would the i7 (125w TDP) be just as efficient as the i5 (65w TDP) at idol? In a NAS would the power draw be much different? The NAS is mainly for home storage use with a bit of plex so 90% of the time they should be idle.
Thank you.

[ed]

Thanks for getting in touch. Between those two CPUs, you’ll see very little difference in idle power draw. Modern Intel chips downclock aggressively when the system isn’t under load, so both the i5 and i7 will idle at roughly the same wattage, usually in the 8–15W range depending on your motherboard and PSU efficiency.

The main difference is under load. The i7 (125W TDP) can turbo higher and sustain more threads, so when Plex transcodes or runs background tasks, it’ll spike noticeably above the i5. For a NAS that’s idle most of the time and only occasionally handles a Plex stream, the total yearly power difference will be small, maybe a few pounds on your electricity bill.

If you plan to run multiple 4K transcodes or a few Docker containers, the i7 is worth it for the extra cores and higher boost ceiling. If it’s mostly idle storage and light Plex streaming, the i5 will run cooler and is plenty fast. Both will idle efficiently, so the real choice comes down to how much future workload headroom you want.