GIGABYTE Z270X-Gaming 8 Motherboard Review

Closer Look: Bitspower VRM Block

Bitspower VRM Block In Depth

GIGABYTE worked closely with several manufacturers in developing their Z270-based boards to give consumers a wide breadth of choices wih which to build their system around. The Z270X-Gaming 8 motherboard was developed in conjunction with the enthusiast water cooling part manufacturer Bitspower, who paired the board with a custom-designed all copper VRM heat sink. The heat sink is of a hybrid design, functioning equally well under active air or water cooling.

By default, the inlet / outlet ports on the VRM chipset are sealed with Bitspower-branded brass G1/4" port caps. While these caps are not necessary for air-based use of the VRM cooler, they keep dirt and debris out of the VRM inner channel. When the port plugs are removed, you can see that the inlet/outlet ports are threaded. Further, the inner channel of the VRM block can be seen, displaying its nickel-plated construction.

Removing the VRM block from the motherboard uncovers board's digital power system – its chokes and VRM chips. There are a total of 11 power phases on the board, each consisting of a choke and dual VRM chips.

Bitspower VRM Block Deconstructed

The VRM block comes off the board easily enough, held securely in place with four screws that go directly into the threaded holes in the bottom of the block. The block is of a multi-level construction with a dual acrylic and copper design. The bottom copper plate is all nickel-plated for corrosion and scratch resistance. By default, the block is factory installed with strips of thermal tape resting in between the block base and the VRM chips.

The block is constructed of a multi-level design with four levels in total. The block is covered by a plastic armor plate giving the block an aesthetic match to the motherboard. Directly below that is a copper plate forming the upper channel connecting the two arms of the VRM. The plate fixes directly into the acrylic peice which forms the connecting channel between the two VRM blocks and the channel for the VRM blocks themselves. All are sealed to one another with rubber seals ensuring a water tight fit. The acrylic piece fits to the copper VRM blocks with screws that thread directly into the top of the blocks, forming the L shape of the block.

Removing the top armor plate reveals the construction of the block with its L shaped upper plate fixed to the middle acrylic part and the screw heads mating the acrylic piece to the VRM blocks. The two port covers sit on opposite sides of the L shaped acrylic piece. The acrylic comes with a smoked finish, giving it a semi-see through appearance.

Taking a closer look at the assembly with the upper plate, you can clearly see how the acrylic mid plate attaches to the blocks with the upper channel allowing the coolant to easily flow between them.

Courtesy of GIGABYTE

With the entire block disassembled, you can better visualize the intent of the design. The top plate sits in an indented portion of the acrylic mid-plate so it sits almost flush with the surface. The channel in the top portion of the acrylic piece is lined with a rubber seal, making for a water tight seal. The bottom blocks are two peices, one that fits over the right-most VRMs and the other sitting on the VRMs above the CPU socket. Both are designed with a smooth inner channel giving a good amount of surface area for heat transfer to the liquid medium. While this design does give less resistance and better flow rate, a micro-channel or pin matrix design within the block chambers would dramatically increase the surface area available and cooling effectiveness of the block itself. Both block have outer channels in which the rubber seals fit, used for sealing the blocks to the acrylic mid plate.

Removing the acrylic piece entirely give a better look at its design and how the channels are formed. From the upper view, you can see the delivery hole between the upper and lower channels. From the under view, you get a better look at the location of the inlet and outlet ports for each section.

Bitspower VRM Block Performance

Cooler Testing Methodology

To best gage the quality of the board's VRM cooler, system VRM temperature measurements were taken with the sustem at idle and under load. To replicate idle conditions, the system was rebooted and allowed to sit idle for 10 minutes. To replicate a stress system load, AIDA64 System Stability Test was used in conjunction with EVGA OC Scanner X for 30 minutes per run. After each run, the system was shut down and allowed to rest for 10 minutes to cool down. This procedure was repeated a total of six times for each test run – three times each for the stock and overclocking speed runs on the system.

Temperature measurements were taken directly from the onboard temperature measurement chip using HWiNFO64 v5.52-3161.

To adequately measure VRM block's performance, performance testing was done using two different configurations – in its default air-cooled configuration without fan, with a fan blowing over the block in its default configuration, and with liquid coolant running through the block directly in line with the CPU block.

System with block in default air-cooled configuration

System with block in liquid-cooled configuration

Note that the temperature values are reported as deltas rather than absolute temperatures with the delta value reported calculated as CPU temperature – ambient temperature. For all tests, room ambient temperature was maintained between 23-27C.

System Stock Speed Testing

The CPU stock speed testing was conducted with the BIOS defaults set for the CPU and Turbo Mode disabled, equating to a 4.2GHz CPU speed, 2400MHz memory speed, 4.2GHz ring bus speed, and 100MHz base clock. The Intel Speedstep functionality remained enabled for the duration of the testing to get realistic CPU idle performance conditions.

In its default configuration, the VRM temperatures are significantly higher in comparison to temperatures measured with an active air source blowing over the VRM block or with the block liquid cooled. However, there is negligible difference between the fan cooled and liquid cooled performance.

System Overclocked Speed Testing

The CPU overclocked speed testing was conducted with known stable settings with Turbo Mode enabled, equating to a 5.10GHz CPU speed, 4000MHz memory speed, 4.8GHz ring bus speed, and 100MHz base clock. The Intel Speedstep functionality remained enabled for the duration of the testing to get realistic CPU idle performance conditions.

Board voltage settings were configured as follows:

• CPU Core Voltage – 1.35
• CPU System Agent Voltage – 1.20
• DRAM Voltage – 1.36
• All other settings set to Auto or stock settings

Again we see a significant different between the passive and active cooled performance of the block. In fact, the board was unstable without an active cooling source cooling the VRM block. However, their was no difference measured in the load performance of the block with fan cooled and liquid cooled performance matching. The only difference seen in performance was at idle with the liquid cooled block configuration slightly outperforming that of the fan cooled configuration. There are two factors that could be contributing to the block's insignificant performance gain when using it with liquid coolant. One, the VRMs do not produce a significant amount of heat. Two, the design of the block is more optimized for air cooling with the lack of micro-channels or a pin matrix decreasing the efficiency of the cooler in its liquid-based configuration.