I am considering swapping out my desktop for an eGPU enclosure. I have access to extra P50,51 or 52s at work, and I love the idea of one device for everything. I also have to move my workspace around too often.
So I was looking at https://mymantiz.com/products/mantiz-mz-03-saturn-pro-egpu-v2 . I want a device with extra ports, so I figured I would need an enclosure with 2 Thunderbolt outputs. One for my x4 laptop port and one for the extras in another x1 port. The device touts two TB3 chipsets, but considering it only has 1 type C output, wouldn’t this eat into the x4 port I would connect it to? Thus taking away performance from the GPU?
No, you are right that whatever other USB or SATA ports come off of the single Thunderbolt-Connection can take away bandwidth from the GPU.
Whether this is done with 2 internally daisy-chained controllers, like they seem to with this case or with a single Thunderbolt Controller does not matter. Whether or not an additional Thunderbolt controller actually has reliability or latency advantages, I do not know.
I have seen an ASUS eGPU enclosure that had an additional USB-Input so the bandwidth does not need to come from the Thunderbolt connection. Since all additional Ports seem to be attached via USB anyway there is also no need for a 2nd Thunderbolt Input, USB would suffice to not eat into the GPUs bandwidth.
However, you also need to double-check that the P5x Notebooks are even capable of the full PCIe Bandbwidth, as on their T-Series Lenovo is using the smaller Thunderbolt Controllers that only have PCIe x2 and 1 Displayport.
So far the only reliable way to identify x4 connections are notebooks with dual Thunderbolt Ports, as that requires the high-end controllers with x4 support. If the manufacterer does not list the PCIe connection in the specs, for a single port, they could just be using the gimped version.
-Edit:
even if you had 2 separate Thunderbolt ports on the dock and a notebook with 2 Thunderbolt Ports, more than likely both Thunderbolt Ports would come off the same controller that shares x4 bandwidth for both ports, so there would still be no benefit.
Awesome. Thank you for the response. From what I recall, the P50 had all x4 lanes on the single USB-C port, but I hadn’t considered that on the 51 or 52 that they would share the controller. Luckily, I can grab them and investigate more.
In any case, the used market points to buying a Razer X Core here, so I know I am not getting anything with extra ports. With this comment, I fell comfortable finalizing my research.
If by that you mean, that it would only take away bandwidth from the GPU when data is actually transferred over USB or over the network port, then I agree.
Due to the packetized nature of thunderbolt I am assuming this to be the case. Apologies if that was not clear.
I only read about Displayport bandwidth being allocated statically, but that kind of goes with the purpose of Displayport.