How does i5-8400 compare to fx-8350 (gaming)?

clock speed * IPC speed = real speed, so high clock speed is misleading, 8400 has much better IPC than FX, most games can only use up to 4 cores, so more cores does not translate to better FPS. 8400 wins by quite a large margin in gaming.


The Intel part is a good performer as is the AMD CPU. What Vapour stated about IPC between the two is accurate. While it's not exactly terrible in gaming, the 8350 does just fine even with many of today's triple A titles. The thing to consider though it age: it's 7+ years old now and wouldn't be worth considering if you were building a new rig.

I own an 8350 @ 4.5 on air. It works great and over time has gained ground on some of the Intel chips due to things being more multi threaded as things have gone on. I don't regret building it for a second.

Doctor Rob

Jul 21, 2008
also much newer architecture..

Like I went from an FX 8150 system to an Ryzen 7 1800X and WOW what a difference. thought the old FX cpu was good at the time.. this one is way better! it now hurts me when I have to use older systems with slower intel or amd processors.. if you are looking to do a new system I would really recommend an amd Ryzen 5 or 7 system (especially being they will support it much longer then intel will).. I am looking to next year if they come out with a faster cpu then the Ryzen 7 2700X to upgrade to that next year as it will still be supported on this platform.


The FX 8350 has 8 "cores" not full cores. What AMD did with the FX series was used a more advanced version of SMT that had modules that had most of two cores with some shared resources. That means that when fully loaded the FX 8350 would lose out to a 6 core or even most 4 core CPUs.

To top it off it had pretty low IPC as stated above which compounded on the core design for performance.

Suffice to say your 8400 is a better CPU.
Even an I5-2500k has better IPC than the FX-8350. In fact sandy bridge I5s and I7s still perform much better than the FX 8350 in games... that's the reason why AMD failed on this architecture.
So, you can imagine that an i5 8400 will stomp the piledriver chip in games.
If anyone is recommending to you any pre-Ryzen AMD platform, in lieu of a modern platform, punch them first, then ask them why they are trying to sabotage you.

No contest. i5-8400 is superior. Any Ryzen is superior.


To say it another way, clock speed and core count are only useful when comparing CPUs from the same family and really the same generation. So if you are comparing say an i3 6100 and i5 6600K then the clock speed and core count will give you a very good Idea of the relative performance and if you stick with intel it would also be ok to compare to say an i5 7500 series because they are very similar in design to the 6 series and perform much the same.

As soon as you start comparing to other designs though it's no longer useful. An Athlon X2 4200+ vs a pentium D 945 to go for an oldschool example would seem to be all in intels favour having the same number of cores and 1.2ghz extra clock speed - but they perform almost the same because the AMD was a much better design at the time, then intel brought out the core 2 design and things reversed.

IPC = instructions per clock and is a measure of how fast a CPU is at a particular clock speed, they are a long way from all being the same.

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