I don't usually pay much attention to emails from manufacturers who claim that a particular motherboard can overclock a Skylake Core i7 processor or that they have claimed the 3DMark record. In my eyes, they're boring marketing tactics that mean little to nothing to the consumer.
I received an email from Asrock last month that caught my attention. It was claimed that the Z170M OC Formula was the only motherboard that supports the G.Skill Trident Z DDR4-4333 modules. At first I thought how useful is that? Are there any advantages when running DDR4 memory on the LGA1151 platform so high?
For the most part, we test with DDR4-3000 because it occasionally shows some advantages over the typical speeds of 2400 and 2666. Reaching 4000 MT / s (2000 MHz) and beyond means a massive increase in frequency (and cost), and I struggled to imagine where this would be useful, especially when playing. On the other hand, curiosity had overwhelmed me …
So I asked Asrock to kindly send one of their Z170M OC Formula motherboards. Disappointingly, G.Skill had no DDR4-4333 memory available, and a month later there is no sale yet, making this news report more and more like a marketing exercise.
However, G.Skill came back and said they could provide an 8 GB kit of their DDR4-4000 memory that is available for purchase. It is not the record-breaking DDR4-4333 memory, but at 4000 MT / s it is not far away and certainly gives us a clear indication of whether or not this type of high-frequency memory has any value.
Some DDR4-4000 memory kits from G.Skill, Corsair and GeIL are currently available. Of these TridentZ modules from G.Skill, the best timings at 19-21-21-41 seem to be possible compared to Corsair's 19-23-23-45, while the GeIL kits at 19-25-25-45 are even looser are .
For testing, we will use a few selected applications and games that compare the Core i7-6700K at different memory speeds from 2133 MT / s to 4000 MT / s. A pair of GeForce GTX 980 Ti graphics cards will help maximize gaming performance. If you cannot use the potential of DDR4-4000, we fear that nothing will be able to do so. With that said, let's get down to business.
Test system specifications
Memory bandwidth benchmark
From DDR4-2133, we see a throughput of only 20.4 GB / s, which is not bad, but less than what we immediately saw from the Haswell processors. Increasing the memory frequency to 2400 MT / s increased the memory bandwidth by 12% to 22.9 GB / s, which was normally the case with Haswell processors.
The speed at which we test regularly increased from 2400 MT / s to 3000 MT / s and increased the memory bandwidth by a further 20% to 27.4 GB / s. Surprisingly, the next step to 3600 MT / s again increased performance significantly, this time by another 20% when we reached 33 GB / s. At the last stop at DDR4-4000, the memory bandwidth reached 35.5 GB / s, which was 8% faster than the configuration at 3600 MT / s. While theoretically the first benchmark is promising, should we go to the real world?