With the release of Intel's Skylake processors, motherboard manufacturers are scrambling to get new Z170 boards released and on the market. Biostar isn't announcing as many boards as ASRock, Asus, Gigabyte or MSI, though, instead pushing out only three boards (like EVGA). However, it appears that there are a few problems in the board design.
Don't Want ATX? Too Bad.
It may disappoint some users to see that Biostar is only shipping Z170 motherboards in the ATX form factor. This strategy is questionable, as Biostar effectively removes itself from competition in the mini-ITX and microATX form factors. It is likely that Biostar plans to use motherboards incorporating other 100 Series chipsets to target these chassis, but, at least for the time being, the company is leaving this segment of the market unattended.
Nice Specs With Dual NICs. What's Not To Like?
As far as the feature set of these motherboards go, not a lot of changes from board to board. For onboard connections, the top end motherboard, the Biostar Gaming Z170X, features three SATA Express connectors, two M.2 Key M slots, and a solitary USB 3.1 Type-C port. The board uses both an Intel i219V and a Killer E2201 for interfacing with the network. The audio sub-system is built around a Realtek ALC898 codec.
The mid-range board, christened Biostar Gaming Z170W, is essentially a slightly cut back version of the flagship board. The board loses one M.2 Key M and the M.2 Key A. It keeps the dual NIC setup, but the Intel NIC is gone, replaced with a Realtek RTL8111H. Very little else changes between the Z170X and Z170W.
Moving to the last board, the Biostar Gaming Z170T, we see that a few more features are cut. The board drops one SATA Express connector, and USB 3.1 support is also removed. Oddly enough, there are still two NICs onboard, but this configuration changes again to use the Intel i219V and Realtek RTL8111H. The last real change of consequence on this board is the downgraded audio chipset, which is now a Realtek ALC892.
Where The Trouble Starts
Examining these boards, we find that there is one major flaw in their design, and it is related to the PCI-E systems. For the PCI-E connectivity on the Z170X, Biostar opted to place three PCI-E x16 3.0, three PCI-E x1 3.0 slots, and a PCI-E M.2 Key A slot. The Z170W dropped one PCI-E x16 and PCI-E x1 slot each, which are replaced with two legacy PCI ports. The Z170T's PCI-E connectivity is the same as the Z170W. All of this appears to be fine, but how these ports are configured is what causes the problem.
The new Z170 chipset replaced its legacy PCI-E 2.0 lanes for 20 lanes based on the much faster PCI-E 3.0 standard. In conjunction with the PCI-E lanes from the CPU, the motherboard has a total of 36 lanes at its disposal, and is technically capable of running three GPUs in an x16 + x8 + x8 configuration.
On the Z170X board, however, Biostar opted to use only the CPU's PCI-E lanes for the x16 slots. The result is that many of the chipset's PCI-E 3.0 lanes go unused, and a three-GPU setup is forced into a bandwidth-constrained x8 + x4 + x4 setup instead, hampering performance.
The Z170W board doesn't really have an issue with PCI-E, as both x16 connectors run off the CPU, allowing for an x8 + x8 configuration. On the Z170T, however, the second PCI-E is connected to the chipset. On the one hand, this would be great if Biostar let it have 8 or 16 of the chipset's PCI-E lanes, but instead it gets tied down to a sparse four lanes. This handicaps the board and will result in throttling when using a multi-GPU setup between two reasonably high-end GPUs.
Overall, these motherboards are about what we would expect to see from Biostar. The company tends to slightly lower spec chipsets to help reduce costs. This is why we see the Killer 2201 chipset on these boards, while most companies are opting to use the Killer 2400 NIC instead.
The end result is typically a board that is still feature rich, as the chips it uses aren't bad by any means, and there's some cost savings there, too. What is surprising though, is that we see the PCI-E systems on these boards configured poorly. It isn't a cost cutting measure, but one of poor design, which might come back to bite Biostar in the long run.