ASRock X399 Professional Gaming sTR4 SATA 6Gb/s USB 3.1/3.0 ATX AMD Motherboard

Review is based on running bios version 3.30 with an AMD Ryzen Threadripper 2950X, My ram was chosen from the board's QVL specifically Corsair's CMW64GX4M4A2666C16 Kit, using 2 1080Ti cards, 1 M.2 SSD, and 2 HDDs. Board is stable, well built, and is easy to use and configure and runs without the slightest issue (although the boot is somewhat slower than what I'm used to (boots in about 26-27 seconds on an SSD and the BIOS load is arguably the slowest part of the boot as once windows actually begins loading its ready in seconds. If I could pick two things I'd change about the board: Include a USB 3.1 header, include more fan headers. It would also be really nice to see M.2 heat shields although maybe its not even needed since my system runs fine either way...

This mobo has worked out really well with the 2990WX I stuffed into it. I do not do any extreme overclocking so my rating is not based on OC capability, but the mobo had no problem XMP'ing 8 3000 Mhz sticks. I'm using a Noctua NH-U14S for cooling.Before configuring for its intended operation I did mess around with the overclocking. Memory overclocking worked like a champ, it seemed to have no trouble running 3000 Mhz memory in all 8 slots (that's the highest speed memory I have). Though for actual operation I stuffed 8 32G ECC sticks in and those are only rated at 2133 (I run them at 2666 with slightly higher memory voltages).Socket overclocking is accomplished by using XFR2 in manual mode, unlimiting the current settings and setting an overall wattage limit for the socket. That's really the easiest way to do it. Stock settings seem to want to pull in the ~350W range at the wall. I could ramp the 2990WX up to 450W at the wall (about the limit for my PSU) but honestly performance did not improve all that much if any and after a few scary power downs from messing around too much (that required some cool-down time before the BIOS would boot again) I decided that was the end of my career as an over-clocker :-)I also experimented with underclocking it... not really underclocking the frequency, but again using the PPT (socket power) limit in XFR2's manual mode to set the socket power ridiculously low. So low that the whole system was pulling only 150W at the wall with all cores fully loaded. And yes, that actually worked! Of course, the all-cores frequency in that case winds up being less than 1GHz, but the BIOS was able to do it which really impresses me. In that mode of operation it actually made sense to run the memory fabric at a slower speed (2400 or 2666) to give the CPU cores a larger portion of the power budget.For actual production operation I run 128GB of ECC at roughly 2666, plus manual XFR2 mode with PPT set a little lower than stock. I have the PPT (socket wattage) limit set such that the whole system pulls around 250W at the wall (instead of 330W at stock settings), with only a slight performance loss for the workload. I also feel that the modest memory fabric frequency helped the cores in this power-limited mode of operation. That gave us a huge, huge improvement in power/performance efficiency which matters more to us since we're paying the electricity bill. By my calculations, the most efficient point is probably around 215W, but running it slightly hotter at 250W gave us a bit of a goosing without losing too much efficiency, and 250W is still way under the stock 330W that it wanted to pull at the wall so I'm a happy camper.-Matt

This is my first ASRock board. It had the features I was looking for and they've been building a good reputation for a while now. Not disappointed. I've got 3 M.2 drives in there and I'm booting between 2 different Linux distros and Windows 10 with no fuss. I've only ever been the most casual of overclockers but this board has been the easiest I've worked with. The board feels solid and seems well made. Nice layout. Really easy. I'd recommend to anybody building a Threadripper system.

I have bought this board for sake of building a home server.Setup: I had a trouble initially with getting the CPU (1950x) to work with the board which reported undocumented c0 error. I was then able to get it to work by removing the CPU and reseating it several times. I think Foxconn is the one to blame for making low-quality CPU sockets which caused a lot of frustration for x399 users across several board manufacturers.OS Installation: I've installed windows 10 seamlessly without any troubles and loaded all the drivers successfully in no time.Asrock software:1) Asrock Bios is good and bios reset button on board became handy on several occasions2) AsRock LED software crashed several times which is not big of a deal.Ram: Had no problem running a quad 3000 MHZ RAM corsair dominator at full speed.10G connection: Windows report that the connection speed is 1G, that might be because I've connected it to a 1G switch.The overall experience so far is good as this is my first Asrock board.