I have an LSI 9600-24i which I’m installing on an AsusRack B650D4U-2L2T/BCM. It and the four onboard SATA will be running at least 15 SATA HDDs and 12 2.5" NVMe. It’s an PCIe 4.0 x8 card, but the GPU (RTX 4000 Ada) and a PCIe 3.0 x4 Intel Optane (write-cache) are taking up the existing slots.
Do I drop the Optane and use the PCIe x4 with the slot physically modified or should I use PCIe bifurcation to split the x16 slot between it and the GPU?
Both the GPU and SAS/NVMe card are Half Height, so I think i can fit PCIe flex and bifurcation under them
No matter what you do, something is going to get compromised. TryTwiceMedia suggested that if the optane is in the form of m.2, then to drop that. This is would normally be advice based on lesser of evils, the question would be:
Is you Optane set up as “CPU storage” in the bios? if it is the performance impact of removing it is a significant drop.
Bifurcation may be your best bet depending on how the Optane is set up
lastly, is your bios capable of bifurcation settings “in the bios”, aka does the bios allow the various 16x, 8x8x, 4x4x4x4x, etc on each slot?
If you’re trying to optimize space and slots, I’d recommend going with PCIe bifurcation to split the x16 slot. That way, you can keep the Optane for caching and not lose out on its benefits.
Yup, the optane is PCIe. A 1.5TB 905P which is the reason I’m so reluctant to drop it from the system.
x8 x8 bifurcation of the x16 is supported in the BIOS of the B650D4U, but I’ll need to do it via PCIe Flex & bifurcation board as there are only three physical slots (I’m using the 1x for a dedicated NPU).