The demand for external graphics (eGFX) has increased over the past few years due to the popularity of versatile ultrabooks. For many, an ultrabook provides all-day battery life in a portable form factor. A major drawback is the less-than-desirable graphics performance. This need is met by pairing an eGPU. However many Thunderbolt 3 eGPU enclosures are bulky, only serving one function. Enter the VisionTek Mini eGFX, a PCIe eGPU enclosure that sports the smallest footprint to date and provides useful expansion ports most ultrabooks lack. The purpose of this enclosure is to further advance efficiency in the mobile workplace and portability in the student gamer lifestyle.
|PSU max power||240W|
|GPU max power
|Power delivery (PD)
|TB3 USB-C ports||1|
|Max GPU len (in/cm)
|Updated firmware||40.1 ✔|
|TB3 cable length (cm)||50|
The VisionTek Mini eGFX‘s most appealing trait is its small size. Build quality is average with the front plastic fascia in matte black finish to match the thin sheet metal body. The appearance is controversial. Perforation is a little overboard and appears somewhat of an afterthought. Given there’s no wasted space in the Mini eGFX, ventilation needed to be as open as possible. The entire unit measures at 2.30 liters and weighs .85 kilograms. It’s a remarkable difference compared to the most popular eGFX currently, the Razer Core X that comes in at 14.45 liters and 6.48 kilograms.
An eGPU enclosure this compact must start with a mini-ITX graphics card as the foundation. The design approach was to utilize all possible interior gaps between the graphics card and the PCIe slot. For example the expansion Ethernet port neatly fills the GPU’s rectangular cutout in front of the PCIe slot. It results in an unusual placement of I/Os on all four sides. Opposite the Ethernet port is a 6-pin PCIe power port. One Thunderbolt 3 port and two expansion USB-A 3.1 Gen 1 ports reside at the front of the enclosure. Once you install the graphics card the rear becomes populated with even more ports for monitor outputs. I came to fully appreciate the design after seeing the components of this enclosure inside and out.
Dual Thunderbolt 3 controllers are another highlight of the VisionTek Mini eGFX. It’s a premium feature that so far only exists in the Razer Core V2. In contrast to single TB3 controller eGPU enclosures with expansion I/O, the dual-TB3 controller setup doesn’t suffer lagging issues through attached peripherals during heavy eGPU use. The second TB3 controller is essentially an internally daisy-chained Thunderbolt 3 dock that provides stability to expansion ports.
The VisionTek Mini eGFX mainboard is the most compact one I’ve seen. The primary Thunderbolt 3 controller [JHL6540] attaches the eGPU to a 4-lane PCIe 3.0 connection. The secondary Thunderbolt 3 controller [JHL6240] attaches the USB controller and Ethernet controller to a 1-lane PCIe 3.0 connection each. Other components typically found on Thunderbolt 3 eGPU enclosures are Texas Instruments TPS65983 USB-C controller and Winbond EEPROM firmware chipset.
In order to build an enclosure barely larger than an ITX graphics card, an external power supply was necessary. The included AC power adapter is a 240W [12V ~ 20A] unit. It provides one 6-pin PCIe power connector. Once plugged into the VisionTek Mini eGFX, it powers the main board directly and the graphics card indirectly through a PCIe power extension cable. A male 6-pin plug connects to the mainboard and a male 6+2-pin plug connects to the GPU. We’ve seen external graphics enclosures such as the ASUS XG Station Pro and Sonnet Breakaway Puck use external power bricks to either manage heat and noise or make their footprint smaller. The VisionTek Mini eGFX uses the AC adapter for both purposes.
One nice thing about the standard PCIe power plug is the ease of running the VisionTek Mini eGFX with a more powerful PSU. The prerequisite is a 12V single rail output. I’ve used an Enermax Revolution 650W SFX power supply to run a Radeon RX Vega Nano Edition. This graphics card has a 175W TDP which is higher than the 150W Max GPU output of this eGFX (through stock 240W PSU). Therefore it would crash my test hosting system during heavy usage. With the much beefier 650W power supply, the Vega Nano did not experience any hard crashes. Keep in mind this is a modification outside of manufacturer specifications.
In order to install or replace the graphics card, you need a Philips screw driver. There are three screws along the rear edge holding the side panel in place. Once the screws are out, the L-shaped side panel can slide towards the rear of the enclosure. Both the side panel and enclosure frame are made of thin sheet metal. Due to the perforated construction, they’re not very strong. Take caution not to bend them which may cause alignment issues during reassembly.
The next component to remove is the cooling fan and its bracket. With miniature enclosures come small and rather fragile components. The AKASA 80mm fan is suspended through two horizontally-placed metal brackets spanning the length of the mini eGFX. Before removing the four screws that mount the fan bracket to the frame, carefully dislodge the fan connector on the mainboard. If you pull on the slim black and red cables rather than the connector, the cream-colored socket may come off the board. This cooling fan’s sole purpose is to dissipate heat from the back of the eGPU directly outside. As we’ve experienced, eGPU enclosures with small fans emit a high-pitched noise. In idle state the noise is mostly from the enclosure fan (~40dB). Once under load, the graphics card cooling fan surpasses the noise of the enclosure fan.
Testing & Benchmarks
Thunderbolt firmware version can be found in macOS System Information <-> Thunderbolt tree. The VisionTek Mini eGFX comes with two individual firmware, one for the primary TB3 controller [40.1] and another for the secondary TB3 controller [17.1]. The primary Thunderbolt firmware sets Power Delivery at 45W. It’s sufficient for most ultrabooks. Thunderbolt 3 ultrabooks such as the 13-inch MacBook Pro require 61W, but the battery should charge albeit at a slower rate. Given the limited 240W PSU, this is a reasonable compromise between providing sufficient power to the eGPU and the host laptop.
The VisionTek Mini eGFX‘s two Alpine Ridge Thunderbolt 3 controller arrangement is rather sought after. When we first saw this feature on the Razer Core V2, we questioned how dedicated PCIe lanes for expansion ports were possible since one Thunderbolt connection from the host computer can carry at most 4 PCIe lanes. If the eGPU was to utilize all 4 PCIe lanes, how are there more lanes for expansion ports through a second Thunderbolt connection?
What Intel did in this arrangement was to attach the expansion Ethernet and USB ports directly to the PCIe lanes exposed through the second Thunderbolt 3 controller [Alpine Ridge JHL6240]. This controller is then daisy-chained to the primary TB3 controller [Alpine Ridge JHL6540] that hosts the GPU. Low-latency devices such as the mouse and keyboard don’t use much bandwidth. While they technically have full access to x1 PCIe connection, they don’t impinge on the x4 PCIe connection of the eGPU. Storage devices such as USB solid state drives may use up to 5Gbps of the max 22Gbps Thunderbolt 3 bandwidth. The gained advantage is minimal latency due to higher priority of service. This configuration ultimately stabilizes the expansion ports during heavy eGPU load.
In single Thunderbolt 3 controller setups, the expansion I/Os go through a USB hub prior to getting PCIe access. This arrangement has lower priority of service. During high eGPU load, inputs through the expansion ports are delayed. Additional latency is amplified during gameplay when input is not reflected in real time. This USB expansion lag issue has plagued the majority of eGFXs with expansion ports. A firmware solution of halving the Host-to-Device bandwidth helps, but it robs the already limited Thunderbolt 3 speed.
One limitation of portable eGPU enclosures is the smaller selection of graphics cards. Not all graphics card series have a mini-ITX model, and the power restraints in this VisionTek Mini eGFX narrow the choices. Apple made this short list even shorter by only supporting AMD cards in macOS. For this review I sourced a few mini-ITX graphics cards. The first GPU is a Radeon Pro WX 4100, a good card to drive four external monitors. As of macOS 10.14.2 Mojave, there’s official external graphics support for the WX 4100. The second GPU I tested was an RX 570 8GB that came with the Limited Edition VisionTek Mini eGFX bundle. It’s a balanced approach in achieving graphics performance boost at a reasonable cost.
The other two AMD graphics cards are R9 Nano and Vega Nano. VisionTek does not officially support these GPUs due to their high TDP. In addition the R9 Fury Nano is part of the Fiji family of graphics cards that has poorly optimized drivers in both Windows and macOS. I like the R9 Fury lineup a lot, especially the Nano version because of its tiny footprint and full fat chip. To use it as an eGPU in macOS, I relied on Mac_editor‘s Purge-Wrangler script. The RX Vega 56 Nano Edition has native eGPU support in macOS but, similar to the R9 Nano, it requires more power than the 150W the external AC adapter can provide. Below is a table of ITX graphics cards that may work with the VisionTek Mini eGFX enclosure.
|Nvidia GeForce ITX||AMD Radeon ITX|
|RTX 2070||RX Vega 56 Nano|
|RTX 2060||Pro WX 5100|
|GTX 1660 Ti||Pro WX 4100|
|GTX 1070||R9 Nano|
|GTX 1060||RX 570|
|GTX 1050 Ti||RX 460/560|
For professional visualization and rendering performance I ran SPECviewperf 13. SPECviewperf is a trusted suite to measure graphics performance based on professional applications. The host laptop was a 2018 13″ MacBook Pro running Windows 10 1809 [i5-8260U, Intel Iris Plus 655 iGPU, 8GB RAM, 512GB SSD]. The Radeon drivers were the modified Adrenalin 2019 19.3.1 from BootCampDrivers.com. Below are the results of the RX 570 8GB, R9 Nano, and Vega Nano through the VisionTek Mini eGFX as well as the Intel iGPU.
|2018 13" MacBook Pro||Iris Plus 655 iGPU||RX 570 8GB eGPU||R9 Nano 4GB eGPU||Vega Nano 8GB eGPU|
At $350 MSRP the VisionTek Mini eGFX is a good value for enthusiasts who have been looking for a small eGPU enclosure. It truly offers a one Thunderbolt 3 cable solution. Dual Thunderbolt controllers sweeten the deal as the only alternative to the Razer Core V2 that retails at $500. While the looks are nothing to write home about, its design function is to do the hard work behind the scenes rather than be the center of attention. In a small market and with even smaller dimensions, the VisionTek Mini eGFX excels by combining mobility and utility.
VisionTek built a Limited Edition Mini eGFX bundle that retails for $500 and includes a Radeon RX 570 8GB graphics card. It also includes a swivel HDMI cable and other promotional goodies. This package is available in very limited quantities during initial launch. As a welcoming gift to eGPU.io community, VisionTek has reserved one Limited Edition unit for a giveaway. To enter please leave a comment below with your host computer and your intended use. We will pick a winner on April 15th, 2019.
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