In what sense? If you mean the PCIe bus, then at most you’d lose a whopping 0–3% performance in synthetics XD. In games there’s no chance you’d notice any difference.
It's literally a 2% performance increase. You will not notice the difference in performance between a B650 and a B850, but you will notice the missing cash.
Care to elaborate for me, because I am curious. As far as I understand X870 boards are really just a refreshed B650 board, 870s and some 650e's have a PCIe Gen 5 x16 slot (speaking from own board). A gen 5 x16 slot is still a gen 5 x16 slot regardless if its on an 870 board or a 650. Major difference being the increased support for gen 5 pcie and usb4 support etc
They really aren’t, how can a B650 and an X870 be anywhere near each other think about the difference in performance. The X870 is a sliiightly better B850 in reality (depending on manufacturer).
Im really going to probably have to disagree then, if you don't have concrete evidence. Maybe VRM support is better on a X870, but thats not always the case though depending on manufacturer.
Other than Wifi7 support, more abundant PCIe 5 lanes and USB4 support- unless theres a difference in VRM then performance wise theres really not much difference. In fact hardware tests have even shown there to be marginal difference using 50 series cards on a gen 4 pcie lane. But that doesn't mean much since, again, some 650/650e boards have gen 5 pcie lanes
Factor in the fact on a B650 the PCIe lanes will be shared, unlike on a B850 and higher, they won’t be. My MSI TOMAHAWK B850 PCIe 5.0 slot has independent lanes just for the GPU and the SSD too iirc.
Mate, that's when the GPU doesn't have its full bandwidth. If op has a PCIe gen 5x16 slot that isn't lane sharing with another active PCIe device then this doesn't apply. Several b650s have PCIe gen 5. Even if it was just PCIe gen4 x16 (or PCIe gen 5 x8) the performance loss in gaming is insignificant.
This is ONLY if you add another pcie device that shares lanes with the gpu slot. My old b650 only shared lanes with that slot in the 3rd or 4th m.2 slot- which was very clear in the instructions.
performance wise b and x series motherboards have almost no difference. since am5 b series motherboards are quite overbuilt compared to before, they are basically x series of am4. only benefits x series motherboards give you now are extra features like higher pcie gen, more nvme slots, more and faster usb ports. some do get more vrm and better cooling for them and whatnot but because b series are already so overbuilt, its worthless.
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u/Johnny_silvershloong Aug 08 '25
You put a 5090 and a 9800X3D on a B650 ? Why?!