I bought Ryzen Threadripper 2950X CPU and ASUS Prime X399-A motherboard.
And now I wonder what memory I need to install for maximum performance. I think the main problem is very poor information on AMD website (or maybe I don't understand this information correctly).
On AMD website you can find line: «System Memory Specification: 2933MHz» on each 2nd Threadripper's page. But in the QVL for the motherboard you cannot find any memory with 2933MHz! Here is many frequencies in the list: 2133, 2400, 2666, 2800, 3000 and even 3200. But where 2933? Does 2933MHz just a recommended memory frequency? Or what is this number mean, if it doesn't? This just blowing my mind. Help!
I found a similar questions on this forum but they all are without any reply.
2933mhz is the "officially supported" memory speed, anything faster than that is considered "overclocking", but does not void any warranties and is not dangerous in any way. Speeds above that vary from motherboard to motherboard, and you should go by the QVL list on your motherboard's support page. If they're listed there as supported, then it'll run at that, just make sure you get the fastest speed on there due to the Ryzen archetecture's Infinity Fabric running at the RAM speed.
fullylobsted, there is really no absolute memory frequency. The MB and memory vendors test their products and publist lists. The user goes from there using experience and opinion from others. I have a 2990WX - specifications:
MSI X399 Creation, Threadripper 2990WX, 3xSamsung SSD 970 EVO RAID0, 4xSSD 960 EVO on MSI AeroXpander RAID10, 1TB & 500 GB WD Black, G.SKILL Flare X F4-3200C14Q-32GFX, Windows 10 x64 Pro, EnerMax-MaxTytan-EDT1250EWT, Enermx Liqtech TR4 280 CPU Cooler, Radeon RX580, Aquantia 10 GbpS Ethernet NIC, UEFI E7B92AMS.120, AGESA SummitPI-SP3r2-188.8.131.52.
I think the secret to running 3200 MHz is the Samsung B-Dies chips on the memory sticks and I recommend them. I suspect you can run faster than this but it will take some tuning. If you are interested, I suggest you find a OCing forum and ask for help. Enjoy, John.
EDIT: Please read comments by goldenblaster at the bottom of this thread.