B850M-X [WiFi] quick review.

I see ZERO difference in the Specification pages between the original and the R2.0. WRONG! PCIe x16 slot went from Gen.4 to Gen.5.

I also compared all the Gallery photos, and the only differences are the main PCIe slot cover design, and some silkscreen differences. RTC battery warning mark moved, and the logo changed a bit.

Ahh! I see it.
Original's main PCIe x16 slot is limited to Gen.4.
R2.0's main PCIe x16 slot supports Gen.5.

I imagine this is to keep up with what Gigabyte is doing.

I'm not sure if there is actual trace difference or not. I do see that the slot has a different metal design, but I don't know if it's required to support faster PCIe speed.

If someone is brave, try forcing the R2.0 BIOS onto the original and see if it supports PCIe x16 Gen.5 (laugh).


Edited by eccential - 02 May 2025 at 8:53pm

ATF wrote: It's not that old, it's my regular W10 install from the old system. I'd rather not re-install Windows / all apps, though I'm aware it's recommended.

you don't have to re-install, in either suggestion i gave

Edited by M440 - 06 Apr 2025 at 1:15pm

ATF wrote: Also, how do I boot an old Windows install that's on a SSD with a MBR partition table? I've enabled CSM but the screen basically stays blank after the BIOS message.

Hard to tell if it is stalls at bios or os boot.

I would recommend converting to GPT and/or migrating this install to VM.

Edited by M440 - 06 Apr 2025 at 3:47am

terribleperson wrote: I am satisfied because I got a highly capable motherboard that met all my requirements (mainly a 4.0 x4 slot in addition to the x16) for a very low price. Even accounting for the price of an external audio solution, it was an excellent deal. I can't buy an accessory to fix an unsuitable PCIe distribution. I have since purchased a Behringer UCA222 for $19 which solves my audio issue.

Exactly. The performance of a chipset PCIe 4x4 NVMe slot was half that of an NVMe drive in an adapter plugged into the CPU PCIe 4x4 slot. (I checked it over a year ago?”maybe it's better with BIOS updates or the B850.)

You don?™t know what kind of controllers you?™ll be able to install in three years, so having PCIe 4x4 wired to the CPU is a must. I suspect running USB4 controllers through a chipset 4x4 lane is nonsense, even today.

I have better sound cards in my monitors than the onboard one.

It's crazy that people still buy ATX boards in 2025 with an inferior PCIe lane configuration and think they have more features. :)

Ryzen 5 8500G won't support ECC, unless you can find *PRO* 8500G. It's pretty hard to find them, especially so soon after their release.

You're absolutely correct about power consumption. In particular, idle power consumption is way lower with these monolithic APUs that were originally designed for mobile devices (laptops, tablets, mini-PCs). This is precisely why my current server is using Ryzen 3 PRO 4350G. This is a fairly neat Zen2 chip, in that only one of the two CCX's inside the chip is enabled (4-cores, 8MB L3). The other CCX is completely disabled. It's the APU equivalent of the Ryzen 3 3300X, as opposed to the Ryzen 3 3100. It is more than fast enough for my 24/7 server use, and it is incredibly power efficient. Mine is running off DC power supply + optional solar, using Mini-Box M3-ATX "pico" style power supply.

I'd love to be able to buy an AM5 PRO APU, like Ryzen 7 PRO 8700GE, but I don't know where to get one. I got the Ryzen 3 PRO 4350G from Amazon seller who imported them from South Korea. I also got my Ryzen 5 PRO 4650G from a Hong Kong seller. Is AMD an American company or what?

Yes, the lowest cost chiplet AM5 CPU would be R5-7600 or R5-9600. Their idle power consumption will be quite a bit higher than for monolithic APUs, though.

ECC memory just needs to be unbuffered. 2R just means dual-rank. 1R and 2R just indicates how the chips are arranged. All large capacity DIMMs will be 2R because chips just don't have enough bits to do 1R at that capacity. 16GB DIMMs are likely all 1R.

As for the cost of ECC memory, I agree. There's really not that much difference between regular unbuffered DIMM and ECC unbuffered DIMM. I wrote in Crucial.com review, "I'm paying 100% more for 25% more DRAM chips!" (laugh)

Funny enough, ECC RDIMMs (Registered DIMMs) are CHEAPER than ECC UDIMMs. I think this is purely because of the volume. Big data center EPYC/Xeon uses RDIMMs, so the sales volume is way higher than that of UDIMMs. I have no use for giant EPYC chips, though.

Note EPYC 4004 series chips for AM5 are basically the same thing as Ryzen 7000 series, and can only use unbuffered DIMMs.