Dragonfly 16 EGPU

After being commissioned for the Dragonfly 25 EGPU, I saw the potential for a high performance computing setup that would be more portable than my Firefly 44 PC build. Many improvements were made on the Dragonfly 16 as compared to the Dragonfly 25 (smaller numbers are better in small form factor PCs), such as a unified cooling design, 30% smaller build, more budget friendly power solution, and a thinner form factor, which fits much better in a laptop bag. I added an additional challenge of wanting the build to look good with a clear side panel, meaning I had to make the wiring neat and presentable and this required the parts to be arranged such that they could be showcased in the build.

With my HP Envy x360 14" with a Core Ultra 7 125U, this combo is often able to outperform my Firefly 44 desktop in most gaming workloads, thanks in large part to the newer generation RTX 5060.

Like the majority of my projects, the Dragonfly 16 was modeled in Fusion360 for all the components, subassemblies, and assemblies.

Initial part functionality test

Compared to the previous edition Dragonfly 25, the Dragonfly 16 has a couple of improvements in hardware.

• The Gigabyte RTX 4060 has been upgraded to an RTX 5060, offering a modest performance increase.

• The HDPLEX 250W ATX GAN power supply has been replaced with a combo unit using a Mean Well LOP-300-12 combined with a J-HACK ONE2 150P from pico-box, which was chosen due to its slimmer height relative to comparable picoPSUs.

• The bottom panel, which serves as the backbone of the system has been replaced with an aluminum panel with press fit hardware.

Hardware Mods

Much hardware needed to be modified in order to shrink the size of the total build. In order from least to most insane:

1. Low profile PCIe 8 pin

The length of the case was tailored specifically to fit the Gigabyte RTX 5060 low profile. Due to the placement of the PCIe connector on the back of the card, it would necessitate an extended front panel. Instead, the PCIe 8 pin connector, which was already custom spliced to the

Mean Well LOP 300-12, was depinned and

then the connector cut down to reduce the length of the build by ~10mm.

2. USB Port removal on the TH3P4G3

In order to fit the PCIe IO bracket behind the TH3P4G3, the USB3 port needed to be desoldered, which allows the graphics card to sit lower down. This reduced the width of the build by ~20mm. Since the USB3.0 type A port was still electrically enabled, I wired up a USB3.0 to M.2 adapter to it to allow the EGPU to also contain additional storage

3. Noctua NF-A4x10 Fan Swap

The exhaust fan of the system was originally a Noctua NF-A4x10 5V FLX fan pulled from a Prusa i3 MK3. This was plugged into the graphics card with two NA-RC8 LNAs from Noctua to provide a TACH signal to the card for fan control as the modified fans did not support a TACH signal without a pull-up resistor. However, without proper PWM control of this fan, the GPU fans exhibited erratic behavior. I then purchased the proper NF-A4x10 PWM fan to use. As the standard NF-A4x10 is not available in black, I disassembled both fans to swap the motor and anti-vibration pads to make what is possibly the world's only black NF-A4x10 12V PWM

4. ONE2 150P mounting

The ONE2 150P from J-HACK is a DC to ATX picopsu, which takes in 12VDC and outputs the required voltages for the ATX standard. Compared to the HDPLEX 250W ATX GAN power supply, which cost $150USD on the Dragonfly

25, the Mean Well 300-LOP-12 and ONE2 150P combo cost just $70USD and can deliver 50W more power for more power hungry GPUs. However, since the case length is sized for the length of the Gigabyte 5060LP, the ONE2 150P protrudes too far out the front to fit in the case. To fix this, I desoldered the ATX 24 pin connectors from both the TH3P4G3 and the ONE2

150P. I then resoldered pins to the ONE2 150 before soldering it directly to the TH3P4G3. This allowed me to reduce the length of the combined configuration by ~25mm. Additionally, I removed the 8pin CPU connector on the TH3P4G3 and wired the leads for the CPU connector from the ONE2 150P directly to the TH3P4G3.

5. Single slot RTX 5060

The compactness of the original Dragonfly 25 was made possible due to the small size of the Gigabyte RTX 4060LP as it is a half height card. The Gigabyte RTX 5060LP used in this build is also a half height card, but in order to achieve the desired thickness of the build, it needed to be converted into a single slot card. Previously, this was done on my Firefly 44 build using a set of 3 Delta BFB0512VHD-sp01 fans mounted to the top of an EVGA

RTX 2060KO. I attempted to do the same with this build to create a single slot RTX 5060. However, there was one major hurdle compared to the 2060KO; the 5060LP has I/O in both slots. This necessitated removing one of the DisplayPort outputs on the card

using a jeweler's saw -- my original attempt to desolder the connector ended with a dead RTX 5060. I additionally designed a custom I/O bracket for the card as no single slot brackets are available for this card. In the end, this mod on the graphics card was what made this build as compact as it is, saving 40mm in width and 20mm in height for the build. Additionally, due to the availability of the originally used Delta BFB0512VHD-sp01 fans, I tried using Delta BFB0512VHD-F00 fans. These fans do not use PWM control and thus spin at max speed as the 5060LP is not capable of DC fan control. These fans were quite loud, so necessitated finding a set of Delta BFB0512VHD-sp01 fans, which could be PWM controlled, but my troubles weren't over yet. The TACH signal in these fans require a pull-up resistor from 5V on the TACH signal to report any fan speed -- most PC fans have the pull-up resistor integrated into the fan controller. Without any TACH signal to the graphics card, the card will cycle PWM at 100%, also resulting in a lot of fan noise. Instead, I spliced an additional connector to plug in a Noctua NF-A4x10 PWM in order to read a TACH signal and report fan speed.

With the eGPU plugged in, the RTX 5060 massively outperforms the integrated graphics

Due to the bandwidth restriction down to a PCIe 3.0 4x link with Thunderbolt 3, the RTX 5060 does experience up to a 20% performance loss compared to desktops. Additionally, the eGPU was tested with and without the PCIe 4.0 4x riser and I observed no performance penalty despite the slot on the TH3P4G3 being a PCIe 3.0 16x slot.

The final build comes out to 270mm x 190mm x 33 mm, making for a total volume of 1.69 liters, nearly a liter smaller than the original Dragonfly 25 prototype.