[dkjaudyeqooe]

Is there a reason for a dearth of PCIe connectivity on these small SoCs? Is it difficult to implement? Perhaps a pincount issue?

The big problem with these small and cheap systems is that you can't connect NVMe drives to them and you pay a huge performance penalty.

[bradfa]

Generally high speed serdes IO blocks, which are needed for PCIe, in ASIC design are rather high power consumers. Even on Intel and AMD laptop spec CPUs there's generally many fewer PCIe lanes than on their desktop counterparts. The silicon space needed is also not small and sometimes the silicon process for making good low power but high performance serdes transceivers is not the best process for making the other things needed on the SOC, which can be solved with chiplet style designs but then you have another problem.

Most inexpensive and small SOC just can't justify adding such costs and complexities given that it's very likely their target volume buyer doesn't need such features.

I suspect this RISC-V SOC is priced in the $10-20 range, but I have no true understanding of the cost of this part. In that price range for SOCs almost no one has 4 PCIe lanes on offer, but some do have 1 or 2.

[brucehoult]

The rival JH7110 SoC (it's like A55 to this chip's A72 -- slightly slower but cheaper and much lower power consumption) has PCIe. The VisionFive 2 brings one lane out to M.2 NVMe. The Star64 brings it out to a standard PCIe connector.

[dijit]

most SOC CPUs don't really have a huge PCIe capability to begin with- possibly 1 or 2 lanes total; and you probably want USB, Ethernet etc;

You wouldn't get very much performance anyway, as you only want many PCIe links in order to get bandwidth through them which you're unlikely to do on an anaemic CPU.

to-wit: you wouldn't get good NVMe performance even if you had the pinouts and the CPU had 4x Lanes of PCIe anyway.

[adgjlsfhk1]

just having 1 or 2 lanes of gen 3 with an m.2 would be really nice. 2 gen 3 lanes gives you 2gbps which isn't fast compared to the 4 gen 4 lanes on modern ssds, but it's fast enough that it won't slow down the rest of the system.

[nottorp]

> you wouldn't get good NVMe performance even if you had the pinouts and the CPU had 4x Lanes of PCIe anyway.

... compared to eMMc or sata over usb? You won't get the full performance of the ssd, but i guarantee it will be much better.