- Date:
- Thursday , September 25, 2014
- Author:
- Kyle Bennett
- Share:

Core i7-5960X 5930K 5820K Overclocking & Performance
We headed out to Microcenter and purchased two new Haswell-E processors, the Intel Core i7-5930K and Core i7-5820K CPUs. We have spent some time overclocking those and figuring out where the headroom is. Today we discuss overclocking these and what to expect with rock solid stability in mind.
Haswell-E Overclocking
So we have gotten to spend some time with our new processors now, on a few different X99 motherboards from ASUS, GIGABYTE, and MSI. Our reviews of the MSI X99S XPower AC and GIGABYTE X99-UD4 motherboards will be published soon.
The Core i7-5960X that we have used here is an Engineering Sample that was sent to use from Intel. The Core i7-5930K and Core i7-5820K processors were purchased locally. Given much of the feedback that we have gotten from ODM motherboard builders, we actually did not expect to be able to get stable overclocks of 4.5GHz and over.
Core i7-5820K Overclock
Our retail purchased Core i7-5820K was easier to cool than other two processors, as you might guess. Even with our 4.6GHz clock speed. We were able to keep per core temps under 80c for the 24 hours of the torture testing.
We were using the ASUS X99-Deluxe for this overclock with a 1.32v core voltage and a 1.90v CPU input voltage. We did not have any throttling to deal with either. The system was 100% rock solid stable with our Koolance double radiator and the Koolance 380i water block.
Moving up to a bit faster processor clock, costs us quite a bit in terms of voltage and stability as shown above. At 4.7GHz/2666MHz to get any sort of Prime95 stability we had to move the core voltage up to 1.32v and the CPU input voltage up to 1.94v. Pushing all 6 cores and all 16GB of memory we could only muster an hour of stability before we experienced a system crash. This proved to be the case over and over.
Core i7-5930K & Core i7-5960X Overclocks
Our Core i7-5930K and i7-5960X processors were not as agreeable for the long term stresses of overclocking. The best we could get out of the i7-5930K was a little over 3 hours (sorry, did not get a screen shot). This 4.5GHz/2666MHz clock required 1.32v core voltage and 1.92v CPU input voltage. The Engineering Sample Core i7-5960X was a bit more forgiving at 1.301v core voltage and 1.90v input voltage, but we still had issues keeping it stable for long term stretches. Both however would run stress programs like AIDA64 for over 24 hours. We could also take a full length uncompressed Blu-ray movie and reencode it to a smaller 1080p MKV file with success as well. So while I would not feel good telling you these systems at these clocks are bulletproof, these are also far from the edge stability unless tremendously pushed.
Overclocking Conclusions
As mentioned above we used the ASUS X99-Deluxe for all the core data shown to you here, but we did also spend a lot of time overclocking on both the MSI X99S XPower AC and GIGABYTE X99-UD4 motherboards in the last couple of weeks. All of these motherboards acted differently in terms of top end overclocking with our Haswell-E processors. I found that both the MSI and GIGABYTE motherboards required higher processor input voltages to get to the same overclocks.
We also did spend a lot of time fluctuating input voltages looking for "sweet spots." We could bring down the core voltages on our processors and push up the input voltages and get stable overclocks that would give us lower per core temperatures. It is arguable whether or not this is safe for the long term durability of our CPUs, but if you are super-worried about burning up your shiny new processor, you probably should not be doing this anyway. With lesser per core temperatures, long term stability gets a lot easier to produce.
Of course handling the heat that these processors generate is going to be the biggest lynchpin in your system configuration. We don't think it was luck that our Core i7-5820K with the least transistors was the easiest to keep stable. We were simply able to keep it cooler, and our Koolance radiator and water block are hardly lightweight in terms of shedding wattage. I felt as though with the 5830K and 5960X we were simply seeing our cooling system getting heat saturated. There is no doubt that the 5820K is going to be the easiest to cool.
As far as value and building a new system the Core i7-5820K at $389.76 with Prime Shipping is hard to argue with. The "downside" to the 5820K is of course that it has two less cores than the 5960X and a bit smaller cache than the both the 5960X and 5930K. The other "downside" is that the i7-5820K supports less PCie lanes; 28 lanes compared to 40 lanes on the other two processors. I highly suggest that unless you are looking to build a 4-Way SLI system, an X99 with the ability to support three X8 lanes to three PCIe X16 slots, you will be just fine. I only see PCIe lanes being a hindrance if you are looking at supporting four video cards, or if you are building a monster storage system full of HBA cards. Surely if you need those extra lanes the Core -i7 5930K will cost you $584.29 with Prime Shipping. If cost is not a worry, the Core i7-5960X is $1049.99 with Prime Shipping. It is not hard to argue that saving $200 on the 5820K over the 5930K could easily go to that shiny new DDR4.




