E5-2643 or E5-2680 for gaming?

[john-Jackson]

I have a hp z620 with dual e5 2620 CPUs and a gtx 1080 ti. I want to upgrade my pc for gaming and I want to upgrade my CPUs. I narrowed down the two CPUs in my budget to the e5 2643 and the e5 2680. I will be buying two of whatever CPU I am getting.  To my knowledge, the e5 2643 has better single-core performance and better base clock speed but the e5 2680 has more cores. Which CPU would be the best for gaming?

[BeemerBiker]

I would get the E5-2680 and disable hyper threads.  Modern games take advantage of multiple CPUs.  If a game uses 8 cores but 4 of them are actually threads in the same core then the CPU can overheat and is not as efficient as having 8 actual cores.

I guessed your total devices for a power analysis using two E5-2680 and gtx-1080ti here:

https://outervision.com/power-supply-calculator

and come up with minimum 750 watt power requirements.  I hope you have plenty of air flow and can put up with a lot of fan noise for air cooling..  Liquid cooling for 135 watt cpu will take pair of 120mm fans on 240mm radiator each CPU.

[john-Jackson]

Wouldn't the 16 cores of the dual e5 2680 be unnecessary for gaming, since games use at most  8 cores, so better single-core performance would be better than more cores if you're talking about CPUs with more than 8 cores in gaming.

[BeemerBiker · Accepted solution]

---

@john-Jackson wrote:

Wouldn't the 16 cores of the dual e5 2680 be unnecessary for gaming, since games use at most  8 cores, so better single-core performance would be better than more cores if you're talking about CPUs with more than 8 cores in gaming.

---

correct, the 2680 has 16 threads and 8 cores so I would go with that one and all the processing would be done on a single CPU.  With a pair of CPU and 4 cores each (that other E5),  if the app needed 8 cores then CPU access arbitration to shared memory would probably throw in a wait state or two.  A single 2680 has 20mb cache which will fit more of the game into the cache and less into the much slower main memory.

IMHO, with $0.02,  you are turning a server / workstation into a gaming system.  The E5-2680 runs at 2.7ghz and to do turbo of 3.5 is basically  overclocking it for the duration of the game.  Ideally you should be using a gaming system which is designed for running fast and has liquid cooling and air flow optimization.  Everyone has a budget.

With  32 threads you could be running 32 apps modeling cures for SARS-Cov among other useful contributions to science.

http://boinc.bakerlab.org/rosetta/

https://www.worldcommunitygrid.org/

https://boinc.berkeley.edu/projects.php