placebodebil wrote: ↑11 Feb 2025, 07:36
1. Does a direct connection of an ethernet card/kbm/NVME to CPU vs chipset matter?
For z790 apex
Direct CPU lanes:
2 x16 PCIe 5.0 ports that run in x16 and x8/x8 only (if you put x4 in one of the x16 slots it will use x8 and so will the other x16)
1 PCIe 4.0 m.2 port that is x4
Plan:
NVME in CPU m.2 port
GPU in x16 that will run at x8 (idc about losing lanes)
PCIe to USB in other x16
2. Will A 10gb ethernet card be worth prioritizing over a USB card in CPU lanes?
3. m.2 to PCIe adaptors exist are they any good? If so, I could run a USB and ethernet card in CPU lanes by sacrificing the NVME. Will this cause congestion issues?
4. Any recommendations for m.2 to PCIe, USB and ethernet cards
I would refrain from getting a Z790 Apex due to the increased latency from the audio controller.
The ALC4080 that is used in the Apex not only has
a 3x increase in delay (from 30ms to +100ms), it also schedules DPC/ISR on the wdf0100.sys driver, meaning it can interfere with USB devices.
USB DACs / AMPs are not exempted from this, only the 3.5mm jack or the toslink port in a good audio controller can fix this.
Try sticking to ALC1220, ALC1200 or older controllers instead.
When it comes to lanes and which add-on cards you should choose, it entirely depends on what you're after.
it is always best to avoid added overhead from the PCH (chipset) by using CPU lanes as much as possible.
I'll tell you how I'd personally approach this:
1.) NIC-centric
- You opt for a entirely SFP+ 10GBASE-LR (optic fiber) setup, with a appropriate Intel or Mellanox NIC and place it on the CPU lane.
This is financially not feasible for most, as it requires quite a bit of rerouting and networking knowledge. But it would help immensely in battling interference from copper cabling.
2.) USB-centric
- You opt for a ASMEDIA USB controller with it's specific drivers via CPU lane
This is the lower price budget alternative. If you have a good enough onboard NIC already in terms of DPC/ISR performance, then opt for chasing other parts of the SW stack (namely USB in this case)
Take a look at my signature to see benchmarks (albeit somewhat useless, since it's on idle but still “somewhat” relevant) of different USB controllers / USB AIC cards.
For NIC recommendations, take a look at this:
viewtopic.php?f=10&t=10624&start=100#p97139
For PCIe to M.2, refrain from buying Aliexpress adapters and take a look at some reputable brands, for example:
Startech M.2 to PCIe 3.0 x4 adapter —
https://global.icydock.com/product_308.html
Delock M.2 to PCIe 4.0 x4 adapter —
https://www.delock.com/produkt/89836/merkmale.html
Raidsonic Icy box M.2 to PCIe 4.0 x4 adapter —
https://www.amazon.co.uk/RaidSonic-ICY- ... BFZWV?th=1
If you need a PCIe to M.2 adapter —
https://www.delock.com/produkt/62584/merkmale.html
One way to search for adapters is using Geizhals
Here's the PCIe to M.2 adapter filter query:
https://geizhals.eu/?cat=hdadko&xf=1118 ... .2%2FM-Key
It is of utmost importance to keep every device on a separate lane, ideally all through CPU, without any kind of switches present as you've mentioned. 4.0 x8 can lead to performance degradation and lead to measurable macrostuttering.