Question ASUS Zenith II Extreme Alpha - Second M.2 SSD Much Slower than main Boot SSD

[Nick_113]

Hi-

I purchased a new machine from an expensive custom build brand, and it has a ASUS Zenith II Extreme Alpha motherboard. The main C drive is a Samsung 970 Evo Plus. NVME slotted into M.2 slot 1. I purchased a second 970 Evo Plus, and after pulling everything out and finding the hidden second M.2 slot, after plugging in the new card, I am finding it is 2GB/s slower than the first for reading, and 1GB/s slower for writing. I had put this second card into the DIMM.2 slot and because it had similar, slowerly transfer rates, I put it in the M.2 slot, with no improvement.

I am not a hardware guy - I dont know if this could be BIOS or if the card is broken/defective? It seems to work fine in Windows though.

I cannot find the serial on the motherboard, so I am unable to submit a support ticket at Asus unfortunately.

Thanks for any advice,

Nick.

 

[plasticfist]

I've been researching this board because I will need a MB soon, I've already ordered a 3960x, so your post caught my attention. My first thought was an issue due to which PCI lanes in use. I found a nice block diagram in this article https://www.anandtech.com/show/15152/asus-rog-zenith-ii-extreme-review, some of NVMe are on shared lanes, and/or off the chipset not the CPU, depending on what else is connected, and happening in the system it could impact performance. Reading further maybe that is not it.

A few thoughts

• if memory serves your NVMe is not a gen4 (you could go faster with a different NVMe).
• yes BIOS updates could change your fortunes
• you performed the exact same test, with everything else the same? (nothing else occurring on PC). this is important
• how are you testing? it can be difficult to get accurate perf numbers, the OS, the MB, and maybe even the NVMe will all try to accelerate the "apparent transfer rate" through caching and other techniques.

ATM, I plan to run two firecuda 520 2TB (gen4) - RAID 0
tentatively in the M.2_1 and M.2_2 location, with no PCI card in the PCI 4.0 slot 4 (due to share lanes with M.2_2 NVMe).
but hearing about this tells me maybe I should move them around and run some benchmarks if there is something squirrelly with the NVMe slot choices...