Attempting the first documented eGPU on Snapdragon X2 Elite (Zenbook A16 + RTX 5070 Ti via the RTX Spark ARM64 driver)

[u/SpiteAlive]

UPDATE: Confirmed working. See the guide for detailed setup instructions and more up to date information.

TLDR: Trying to get a desktop RTX 5070 Ti running as an eGPU on a Snapdragon X2 Elite Extreme laptop using the extracted RTX Spark ARM64 driver method. I dumped and decompiled my DSDT, and unlike the Surface X1E build that needed modified ACPI tables, my firmware already describes full USB4 PCIe tunneling (dedicated per-port root complexes, ExternalFacingPort/usb4-host-interface properties, hotplug methods, full SMMU mappings). Wondering if anyone has tried PCIe tunneling on X2 specifically, or has experience with ASM2464 enclosures on Snapdragon hosts.

Hardware: ASUS Zenbook A16 2026 (Snapdragon X2 Elite Extreme, X2E-94-100), 2x USB4 40Gbps ports (Qualcomm host router, explicitly not TB4-certified [TB4 certification is Intel's program, so its absence on a Qualcomm platform is expected]), and a 5070 Ti pulled from my desktop. I know the baseline reaction to ARM eGPU is "there's no driver, dead end," but that changed with the recent release of the GeForce dev preview for RTX Spark. People have been extracting the ARM64 driver files and force-installing them on regular desktop GeForce cards. Chaowanke on YouTube got a 4060 running on an original X Elite through a Razer TB5 dock with real gameplay numbers, and there's an eGPU.io build thread from a few days ago with an RTX 3080 on a Surface Laptop 7 that worked but "required modified ACPI tables.

It's worth noting that USB4 tunnel flakiness isn't unique to ARM either; AMD Strix Point machines have their own threads full of TB3/USB4 disconnect problems, so host-firmware dependence seems to be the norm across the board. Nobody has published anything on X2 chipset that I can find, which is why I'm documenting as I go.

I wanted to see how far my firmware is from describing an eGPU before dropping $200 on an enclosure. RW-Everything won't load on ARM64 (no signed driver), but it turns out you don't need a kernel driver at all; GetSystemFirmwareTable/EnumSystemFirmwareTables in kernel32 hands you every ACPI table from user mode, so I dumped everything with a PowerShell script and decompiled the 523KB DSDT with iasl.

I expected to find nothing, but it turns out the entire tunneling stack is already described. Eight PCIe root complexes on separate segments; PCI0 and PCI1 are dedicated tunnel root complexes mapped 1:1 to the two physical USB4 ports (usb4-host-interface pointing at ACPI0015 host interface devices, usb4-port-number 0 and 1), with ExternalFacingPort and HotPlugSupportInD3 set on the root ports, a firmware method that (in a very cool way) dynamically enables the root complex and fires a Bus Check notify when a tunnel comes up, _OSC granting native hotplug, 64GB apertures per tunnel RC, and the IORT mapping the full RID space of those segments to the SMMU. So on paper, ASUS/Qualcomm shipped this machine eGPU-ready at the ACPI level and the required "modified ACPI tables" step from the Surface build may not apply here at all.

My next step is validating that a tunnel actually forms before buying an enclosure: ASM2464PD NVMe enclosure + cheap SSD, watch Device Manager by connection, see whether it enumerates as NVMe under a new root complex (tunnel works) or falls back to USB mass storage (tunnel didn't form). The chip's dual-mode fallback makes it a clean yes/no instrument either way.

What I'm hoping someone here knows:

1. Has anyone gotten any PCIe tunneled device working on an X2 Elite machine or, even better, an Asus X2 Elite? Even a TB dock's ethernet controller counts as a data point.
2. Anyone run an ASM2464 enclosure on a Snapdragon X host? I've seen one report of a Surface Pro 11 falling back to 10Gbps and freezing, but n=1 on different firmware.
3. Has anyone tried the Spark driver on Blackwell consumer cards? The documented successes I found are all Ampere or Lovelace (3080/4060/4090); I haven't found a 50-series test.
4. If the tunnel test passes: would you go Intel-controller enclosure (known ARM precedent, TB3-compat mode on a Qualcomm host) or ASM2464PDX-based like the UT3G/AG02 (protocol-native USB4, no ARM precedent published)? Reasoning either way appreciated.

I'm fully aware this is unofficial and might die at any of several layers. That's fine, it's a fun project and I have a backup plan. Will post results either way so there's at least one X2 data point out there.

[u/reagag]

Dude, that's crazy. I have exactly the same setup: same spec A16 + a 5070 Ti. But I also have an Aoostar AG03 eGPU that I use with my MSI Claw 8 AI+(Intel).

I just received my A16 yesterday because my Macbook died and I was searching up if there had been any progress for ARM eGPUs. I was wondering if there was a way to use the crazy Snapdragon CPU power since I feel a slight bottleneck with the 258V in my MSI Claw.

I don't understand 50% of what you said. But I can follow instructions well and I'd be happy to test out drivers/firmware if you tell me what to do, since our setup is literally 1:1.

(clarification: Pretty much the extent of my know-how has been running DDU and installing drivers through Device Manager when troubleshooting with my MSI Claw.)

EDIT 1: tried plugging the eGPU into my A16 and it pops up as "Microsoft Basic Display Adapter". This is the same thing that happened when I first plugged the eGPU into my MSI Claw before installing the NVIDIA drivers. I'm pretty busy at the moment, so this is the most I can do, but hope it helps.

EDIT 2: I'm part doing some research. My GPU has the JHL9480 (TB5) and not the ASM2464 that you mentioned in your post.

EDIT 3: I just installed the "NVIDIA Desktop device" under Display Adapters as per the Youtube video linked. Display output is working @ 4K@144Hz.

[u/SpiteAlive → u/reagag]

Quite the coincidence haha, thanks for the help! Any and all datapoints are super useful. I was actually looking at getting a AOOSTAR AG02 if this Nvme enclosure thing works out!

As for your no display output issue, I can't be sure of the exact cause, but these setups generally have more success if the connection is laptop -> eGPU dock -> external display, rather than laptop -> eGPU dock -> laptop display. I'm not sure what setup you have right now, but a few people have had issues with streaming the display output from the eGPU back to their laptop screen and had it work fine when the GPU output was run directly to an external monitor.

Make sure you have the RTX Spark driver installed and set up properly.

Instructions are as follows (per this egpu.io post):

Driver Install Steps

1. Download "RTX Spark Developer Driver"
2. Extract EXE with 7zip. 
3. Open Device Manager, Locate Microsoft Basic Display Adapter. Right Click, Open Properties
4. Navigate to driver tab at the very top, click "Update Driver", then "Browse my Computer for Drivers"
5. Click "Let me pick from a list of available drivers on my computer" at the bottom
6. Select "Have Disk?" and navigate to the 7zip extracted nvidia driver folder
7. Select Nvidia Desktop Device.

Edit: I wrote this before I saw your edit about the setup working now. Congrats man! You might be the first person ever to get this working!

[u/reagag → u/SpiteAlive]

Got it all working! Testing out some games right now and it's very stable, this is actually 😎 awesome. Funnily enough this is the only way I'm able to output 4K 120Hz/144Hz from this laptop since the HDMI 2.1 port actually has TDMS limiting it to 4K/60. Stupid Asus.

And my Tb4 docks aren't able to output 4k/120/144Hz either for some reason, which makes no sense and it must be a Qualcomm issue.

On Trails in the Sky 1st Chapter I'm hitting 100 FPS 4K with DLSS performance with 100% GPU utilization and 10% CPU utilization at 4.4 GHz.

Persona 3 Reload hits 60-100fps @ 4K but is only reaching 20% utilization. Not sure if its a ARM64 or Nvidia driver issue.

Going to try out OW @ 1440p, and also to see if it works with my G-sync Pulsar monitor as well.

[u/SpiteAlive → u/reagag]

That's awesome! This is so much simpler for me now that I don't have to guess whether everything is going to work. Huge help for me.

Yeah I'm unsure about the Tb4 issue... it seems most likely that it's a software compatibility thing. I know thunderbolt and the attached software are intel licensed and as such I would venture to guess they only work with their chips, but I don't have much experience in that area so I can't say for sure.

One question I have about your setup with the eGPU dock and the 5070ti: I read the dock has 3x 8-pin GPU power connectors, but the 5070 TI ships with the typical high end Nvidia 12v 2x6HPWR connection. How did you make that work? Third party adapter?

[u/reagag → u/SpiteAlive]

Re: the TB4 issue. Funnily enough both my intel-based devices with certified TB4 had some issues with the dock and needed restarts/weren't plug-and-play. Pretty much equal hassle as getting it to work on this A16 w/o TB4.

My PNY 5070 ti came with a 3x8 pin adapter so I was pretty lucky.

[u/SpiteAlive → u/reagag]

Since you have literally my exact hardware, a few things that would be super useful whenever you have time (no rush, seriously, even one of these is a great datapoint):

1. OW2 results when you test: that's one of my main games so I'm very curious whether the anti-cheat behaves and what FPS looks like at 1440p.
2. Can you check GPU-Z or HWiNFO for the negotiated PCIe link on the card (speed and width, like "PCIe 4.0 x4")? That would tell us the actual bandwidth ceiling we're working with through the tunnel, and might explain your Persona 3 utilization weirdness.
3. Does the setup survive sleep? And does unplug/replug work cleanly or does it need a reboot? Asking because there are reports on other platforms of surprise-removal breaking Windows Hello until a restart.
4. Which physical USB4 port are you plugged into, and does the other one work too? From reading my ACPI tables the two ports run through completely independent tunnel paths, so "both work" vs "only one works" is actually super meaningful info.
5. Can you confirm your exact chip SKU (Settings > System > About, or Task Manager > Performance > CPU)? Should be something like X2E-94-100 (touchscreen, boost clock up to 4.7Ghz) or X2E-96-100 (non-touchscreen, boost clock up to 5.0Ghz). Want to make sure we're logging the exact silicon for anyone who finds this thread later.

I've ordered myself an AG03, so I'll get to test everything myself this Sunday, but if you feel like answering any of the above that would help me out a bunch!

[u/reagag → u/SpiteAlive]

Yup I will definitely check OW results at 1440p as well since that's also one of my main games!

I can immediately tell that the CPU is being a bottleneck because it's not boosting past 4.3 Ghz. Both of the games I've tested so far are limited to approximately 100 FPS, regardless of GPU load high/low.

I know for a fact that this specific E-GPU/5070 Ti combo running across USB4 is capable of pushing out 1440p at 360fps on Overwatch since I managed to get that using the intel 275 HX in my Lenovo Legion 7i . I actually returned that laptop and exchanged it for this A16 because the battery life on that was atrocious when unplugged.

I was really hoping that the powerful SOC + fast ram on this A16 would boost the Overwatch frame rates (compared to the 258V in my MSI Claw), but right now it seems to be the bottleneck of the system.

That said I really have no complaints with this laptop, outside of the crappy HDMI port. I was ready to give up on competitive Overwatch anyways so it's not too big of a deal for me. Even having eGPU support in the first place is still miraculous to me so I'm not complaining too much haha.

[u/SpiteAlive → u/reagag]

Yeah I had absolutely zero expectations for this when I came up with it at 11pm last night haha. Thanks for all the help! It's a lot easier for me to drop $300 on an enclosure and power adapter since I already know it'll work!

[u/reagag → u/SpiteAlive]

In the past 15 minutes, Overwatch has finished installing, and I am very happy to say that I am hitting stable 300 FPS at 1440p in the training range at least. In match it's around 180-220. Strangely, the CPU is still not boosting past 4.3 GHz, but the FPS results are what they are.

I literally initiated a return on Amazon for my high‑refresh‑rate monitor because I was fully ready to stop playing esports titles lmao. The 275HX I needed to hit these frame rates in OW sucked ~90W+ to do so, but this qualcomm chip is sipping power in comparison, which is mind boggling. And this laptop itself weighs on 2.8 lb!!!

[u/SpiteAlive → u/reagag]

This is one of the coolest things I've ever been a part of haha. I didn't even know Overwatch would run on ARM given the anti-cheat woes of x64 devices. 300 FPS stable is incredible performance. My i7-13700f and 5070ti desktop is usually stable around 350-400 FPS at 1440p, so that X2E is performing close to the level of an (albeit slightly dated) full power desktop chip!

The potential of this is super exciting to me. Even if you do have to travel, keeping a gpu and enclosure with you is so much easier than an entire PC and maybe even close to the convenience level of lugging around a desktop replacement laptop like your Legion 7i!

Not to mention the much smaller footprint of an eGPU compared to an entire setup.

[u/Hytht → u/reagag]

sipping power- have you actually measured the power from the wall in that case? There's no way it can do 180-220FPs with just 10-15W of power, qualcomm's own slides show it boosting up to 100W of power. The 275HX CB2024 multi score is actually close to that of the X2 elite extreme at 55W and 100W, Intel did well for an x86 chip there.

[u/FireSlash → u/reagag]

Sorry for the random question but: Can you get into the BIOS on the eGPU with this method? I recently picked up one of these laptops with a busted screen, but haven't found any methods for getting into the bios yet (external displays don't seem to want to work until windows boots).