Haswell vs. Ivy in Gaming – The ECS Z87H3-A2X golden motherboard and i7-4770K

Overclocking

Core i7-4770″K” CPUs are multiplier unlocked and can easily be overclocked to in excess of 4GHz. On the other hand, the non-K CPUs are locked and cannot be overclocked in the traditional manner. Only the base clock may be overclocked which overclocks the entire system. Overclocks of 3-5+% with stability are reported and there can be a small performance boost. The Core i7-4770K also has an unlocked base clock although we did not attempt to adjust it.

We found that we would have liked more practical options in the ECS BIOS and perhaps have better fine-tuning options.  Even ECS could not suggest more than very basic setting for a 4.6GHz overclock.  Some of the naming is also very confusing as “Disable Overclocking Lock” evidently refers to the “CPU Ratio Lock” found on other motherboards.However, we were able to reach a 4.6GHz overclock although it was neither Prime nor Linpack stable. We were unable to get 4.7GHz no matter how much reasonable voltage we applied. We could barely boot into Windows before the system became unstable. Evidently, the issues are not thermal-related as temperatures remained reasonable.

Issues with System RAM and Overclocking

When setting CPU overclocks it is recommended to move the RAM speeds to default, 1600MHz, or lower.  However, we found no stability difference either way and we kept our Kingston HyperX Predator DDR3 at its rather extreme XMP Profile 1 default 2800MHz clocks.

The Ivy Bridge Overclock versus Haswell’s (vs. Bloomfield, i7-920)

The highest overclock we could manage with our Core i7-920 was 4.2GHz and it was accomplished stably with our Thermaltake Frio OC CPU cooler. To achieve the same 4.2GHz with Core i7-3770K we only needed .03V more added over default to stabilize our system. To reach 4.8GHz required an additional.13V and we needed our Noctua NH-DH14. If the reader is interested, they can check out the Noctua NH-DH14 evaluation to see how we reached our maximum overclock with Core i7-3770K, or the Frio OC evaluation to check out the i7-920 overclock.

In contrast, we were able to reach 4.2GHz and benchmark with our Core i7-4770K with stock voltage, but needed 1.300V to pass Linpack stress testing.   At 4.2GHz, temperatures peak in the upper 70s under maximum load, a few degrees over stock settings.  To reach 4.4GHz required 1.320V and temperatures peaked at 85C under Linpack’s load.  4.5GHz required 1.335V and Linpack peaked at 89C.  To benchmark games at 4.6GHz required 1.360V although our i7-4770K wasn’t stable under Linpak and temperatures climbed into the low 90s.  4.7GHz wasn’t possible with any voltage nor with tweaks suggested by ECS.

Here are ECS’ suggestions to reach 4.5GHz or 4.6GHz by changing these settings in the BIOS (after loading Optimized Defaults and setting the RAM speeds to 1600Mhz or lower):

Enter M.I.B. X as in the last above posted screen shot and change the CPU Ratio option to 45 or 46

Change the Enhanced Intel SpeedStep Technology option to Disable

Set the Boot Performance Mode option to Turbo Performance

Change the Spread Spectrum option to Disable

Change the CPU Override Voltage Target option to 1300 (as a starting point)

Change the CPU Voltage mode option to Override

(Enter the Advanced menu in the BIOS)

Change the CPU C3 Report option to Disable

Make sure CPU C6 Report option is set to Disable

Make sure CPU C7 Report option is set to Disable

Make sure Enhanced Halt (C1E) option is set to Disable

Making the above suggested changes worked for us at 4.5GHz with Linpack stable, and at 4.6GHz for benching games.  Although Haswell’s temperatures were good – below 90C under maximum load – we simply could not reach any higher clocks no matter how much reasonable voltage we added. It also made no difference to the stability if our RAM was clocked at 1600MHz or at 2800MHz, so we ran at it at its highest speed.

In all of our tests between Bloomfield, Ivy Bridge, and Haswell, our CPU is clocked at 4.2GHz using a GTX 680. All of our game benching also uses a GTX 780 Ti to differentiate between the processors, with CPU speeds up to and including 4.6GHz. Our engineering sample  of Ivy Bridge’s i7-3770K can be clocked higher, to 4.8GHz or to 4.9GHz, and when we are trying to demonstrate the effects of CPU scaling on performance, these further overclocks are identified on all of our charts.

Let’s head over to our test configuration.