Intel Turbo Boost Implementation Specifics

We have already mentioned some of the operational peculiarities of DFI LANPARTY JR X58-T3H6 mainboard, but we didn’t really dwell on them. It was a small microATX mainboard that is why DFI engineers definitely had to apply extra effort to make sure that none of the important functions would be sacrificed. They might have had to accept a few compromises that led to certain unwanted consequences. Now that we have tested DFI LANPARTY DK X58-T3eH6 we can conclude with certainty that these drawbacks are typical of the entire family of DFI mainboards based on Intel X58 Express. The most significant problem is exceptionally “unique” implementation of Intel Turbo Boost technology. Let’s check out how it is implemented on DFI mainboards using real examples.

When there is no load, the processor clock frequency multiplier and Vcore get reduced due to Intel power-saving technologies. This is what all Intel Core i7 processors do on all mainboards, including DFI LANPARTY DK X58-T3eH6.

As soon as CPU utilization increases, the processor clock frequency multiplier may be increased even above its nominal value due to Intel Turbo Boost technology. However, a lot here depends not only on the mainboard, but also on the type of workload and on the CPU nominal. To make sure that the processor power consumption stays within the acceptable TDP of 130 W existing for all contemporary Intel Core i7 CPUs, top Bloomfield processors will continue working with their default multiplier until the load lowers a little. After that they will increase the multiplier. Our Intel Core i7-920 CPU is the junior model in the family, its default frequency is only 2.66 GHz and its multiplier equals 20. Top CPU models will work even in nominal mode at frequencies over 3 GHz and with multipliers around 24-25. However, the clock multiplier of the Intel Core i7-920 processor can increase to 21 or 22 maximum, so it can’t possibly hit 3 GHz barrier, and hence these limitations aren’t valid for it. In any case and under any load, the power consumption of Intel Core i7-920 processor will stay at an acceptable level that is why in nominal mode its multiplier will increase to 21 even under the highest possible load. It will happen on all mainboards except those from DFI.

The screenshot below shows that beneath the Lavalys EVEREST CPUID utility there was a window of LinX program that was used to load the CPU. The load in this case was maximal (eight threads), the CPU was working in its nominal mode, but its clock multiplier remained at 20 for some reason.

Only when the number of computational threads drops to 4, DFI LANPARTY DK X58-T3eH6 agrees to increase the multiplier to 21.

Most users will hardly be happy about this implementation of Intel Turbo Boost technology on DFI mainboards, but we can’t really consider it a drawback. The CPU works with its nominal multiplier at a lower Vcore of only 1.136 V in our case, which lowers its overall heat dissipation and power consumption levels. Namely, this particular peculiarity allowed us to put together a compact system around DFI LANPARTY JR X58-T3H6. Of course, proper choice of a system case and cooling system are also important parts of this success, but relatively low CPU power consumption under heavy load on this DFI mainboard is also a worthy contribution.

Energy-efficiency is always good, except those situations when you have to sacrifice some of the performance for it, and this is exactly what is happening with Intel Core i7 processors in DFI mainboards. Is there a way to change this implementation of Intel Turbo Boost technology and replace it with a more common and better performing version? In fact, there is and a fairly simple one. If you set the “Set VR Current Limit Max” parameter of the “CPU Feature” section to “Enabled”, the clock frequency multiplier will increase to 21 even with five or more computational threads loading the CPU. And here is proof that this is really so: LinX utility creates eight threads, but the CPU clock multiplier has still been increased to 21.

Despite the simplicity of this change, you still have to pay a price for it. You have to pay special attention to the processor core voltage in this case. The nominal Vcore of our Intel Core i7-920 CPU sample is 1.225 V, and in this case it has even increased above that under higher load. So far, it is not a big deal, but its negative effect will show fully very soon, during CPU overclocking experiments.