4 ms·
Fabric-wise, PCIe 4.0 offers 16 Gbit/s per lane, so a single PCIe x16 device would have 256 Gbit/s of bandwidth available (in each direction), and a single serv
by mrb 7y ago
Fabric-wise, PCIe 4.0 offers 16 Gbit/s per lane, so a single PCIe x16 device would have 256 Gbit/s of bandwidth available (in each direction), and a single server could reach 1 Tbit/s with four NVMe devices on four PCIe slots. There is the overhead of 128b-132b encoding to be considered, but that's minimal (3%). There is also the overhead of PCIe packets to consider, but if the NVMe device supports large maximum payload sizes (1kB+) it should be minimal.
Are there PCIe 4.0 x16 NVMe devices commercially available?
- deleted 7y ago[deleted]
- amarshall 7y agoIt’s worth noting that M.2 & U.2 both have 4 lanes, so anything more would need to be HHHL or FHHL. Anyway, the Liqid LQD4500 has a 4.0 x16 interface and claims 24 GB/s. I don’t wanna know how much it costs, though. https://www.liqid.com/products/composable-storage/element-lqd4500-pcie-aic-ssd https://www.liqid.com/products/composable-storage/element-lq... https://www.servethehome.com/liqid-element-lqd4500-32tb-pcie-gen4-x16-nvme-ssd-oss/ https://www.servethehome.com/liqid-element-lqd4500-32tb-pcie...
- Rafuino 7y agox16 NVMe SSDs aren't very common. The most recent one I've seen is the Micron X100, but that's a x16 PCIe 3.0 device and it's not commercially available yet. Most consumer and enterprise SSDs are x4, though perhaps that may change as better media and controllers are able to saturate PCIe capabilities. Then it's a tradeoff on power requirements though to be considered...
- jordanthoms 7y agoAsus motherboards (and probably others too) support a mode where you can split the x16 into 4 x4 connections and use https://www.asus.com/us/Motherboard-Accessories/HYPER-M-2-X16-CARD/ https://www.asus.com/us/Motherboard-Accessories/HYPER-M-2-X1... to mount them.