DDR4 OFFICIAL Top Speed is 2666 MHz (or MT/s), slightly up from the original of 2133. So, any speed, by any Manufacturer, above either, is according to JEDEC - Overclocked (that due to the particular motherboard/chipset and its release date).

Thanks @Chief24  ... I think that explains why my new Alienware computer's (specs in Signature) DDR4 has a rating of 3200 MHz even when the max DDR4 spec is 2666 MHz. And all 4 slots are used for dual channel 64GB RAM. When buying the computer, I wondered why the 3200 MHz rating was above the DDR4's max 2666 MHz spec. If I've got this right, the additional MHz would only be utilised if the computer is OC'd above its base 3.7 GHz.

Ok .. I'm pretty decided on the Gigabyte Mobo x570 Aorus Master and the Ryzen 9 3950x cpu ... now the memory ..

That Gigabyte Aorus Master, in all variants for AMD boards, both Mainstream and HEDT, have been doing exceptionally well, based on all the reviews I've seen. Can't really go wrong there. I've used their boards in the past (Intel), and have the X99 UD5-WiFi with a i7-5820K running my Windows Home Server in the Basement. The only thing really I've seen complaints on was some of their USB implementation (X99 boards), and some rather poor BIOS/UEFI design. But, all the manufacturers have had various issues, both with Intel and AMD boards.

Again, just do your due diligence on the research, as you have with the memory. Most of the time, when there is a problem with a build, the majority of the time can be traced back to "User Error". That is why I when I am researching for a build, I really pay attention to some of those website "Reviews by Users". Not all is what it seems. Sort of like what we see here in the Forum as well.

@Dexcon Glad that little explanation helped some. Not necessarily that the Memory's overclock needs to be done in conjunction with the CPU overclock, but depending on the manufacturer of the board, some of the settings to achieve different settings could be a reason. But yeah, a lot of times just setting the XMP for the memory will provide a slight OC on the CPU as well. Usually more when the Memory needs a higher voltage than stock setting, say 1.35 instead of 1.2, which will effect the CPU.

I am using the Cosair RGB 3200 23GB (2 DIMMS) running at 3200.

What I've found since Ryzen "1" days (1700X), is that if you clock the RAM wrong, the computer will not boot right away. Sometimes it will shut down, restart by itself several times as it tries the RAM at the speed selected. On the Gigabyte motherboard for the 1700X, if it can not handle the speed, it will default to 2133mhz and boot up. The highest I could get the 3200 Corsair LED RAM to was 2966mhz.

But with the X570 Elite, 3200 (made sure it was Ryzen compatible) for "me" was not a problem. Went to the BIOS and set the RAM speed. That is the RAM's rated overclock speed and it has been running like this for close to a year now.

Pls don't make mistake at RAM.

1, DIMM is Dual Inline Memory Module, we often call it dual channel, and it has mostly 4 slots on the mainboard; theoretically it doesn't matter whether you use all slots or just the half, but in the practise half is better: more space for cooling air and less physical contact of the pins.

2, it is not you or which brand but the mainboard decides which RAM you should buy, you can only choose, together with your CPU and especially by AMD mainboard, which frequency it should own.

3, selecting a mainboard is quite individual with no significant reason, e.g. I choose the ASUS TUF Gaming B550-Plus: A, it has a S1200A audio chip (I will not buy any audio card extra and I use Roccat Kave 5.1-Headset which needs a USB-power supply in the near); B, it's cheap, does fit the Ryzen9 3950x well and this can control a 32-GB dual channel (2x16)RAM with 3600mHz with no problem:

Wow .. this memory thing is complicated and the information available is not consistent and tends to run you around in circles especially at higher speeds ... so far it looks to me like the G.Skill Ripjaws V series F4-3200C16Q-64GVK is approved on the QVL for Aorus Master x570 mobo for Matisse CPU (3950x) . This gives me 4 sticks of 16gb .. Seems a safe bet that I can run these at 3200 if I turn on XMP in the bios. I guess I won't know for sure until I try it .. so technically I'd be overclocking the ram at 3200 ... Of course, I'd like 3600 but that seems dicey and requires more than a simple XMP setting ... I suppose RAM sticks are easy to return if I'm wrong ... The whole point of this is to build a box that runs VP18 to best advantage. From that view, does 64GB of Ram matter?

If you change the XMP profile (with Gigabyte it is fairly easy), if it doesn't work, you can always go back to default, or... the motherboard might do that for you. I would suggest you start with 3200 and work your way up from the default 2133mhz.

It was no problem for me to hit 3200mhz and am quite happy with the results.

3rd gen Ryzen with 3900X RAM testing with gaming.

@xberk  Just checked and verified your Memory selection to the board you have listed (going on the links - trying to open Gigabyte site now, and they seem to be having an issue!), and it is compatible and qualified. Yes, for all four DIMM slots, at 16 GB each. Best thing is, since you are following Gigabyte's QVL, if for some reason the memory does not work on the board, but passes testing (the memory, that is), and turns out to be a board issue, then you should be able to RMA the board with "fewer" hassles. This is one reason why proper research is essential.

If you also look at the far end of the table, it actually lists those particular GSkill modules, as a "Base" of 2133 - JEDEC specification for DDR4.

And yes, with all the current manufacturers' trying to "Top" each other for fastest speed, it really is tough to figure out what will work correctly. And since the Motherboards' typically list the "Top Rated Speed" - usually for Two DIMM's, it makes it even tougher for those that are looking to populate all slots, at the "Best" speed they can get. But as I mentioned earlier, even with the best board and DIMM modules, you are still at mercy of the CPU Memory Controller.

So yeah, the XMP should work fine (some AMD boards might list this as DOCP), and if you do have some issues that you feel may be related to memory, you can always "ratchet back" the speed a bit, or even down to say 2133, 2400, or 2933.

Now, needing 64GB? Only you can really answer that, based on your projects and needs. On any of my X399 computers, which all three are sporting 64GB, I rarely see a much going over 16GB when using them. But, I also look at it as a sort of "just in case" scenario. Again, this is really user preference. I do strongly believe, In My Opinion, that 32GB should be in a computer if someone is editing/rendering 4K/Higher footage - may not use anywhere close to that, but at least you have some "breathing room". As I said, this is My Opinion, and some may not quite agree. But in the end, who cares, as long as your "New Master-Piece" becomes what you envisioned?

Oh, and I do like the choice of your "Updated" components!

Fractal design cases look good as I want to use about 5 or 6 old HDD (mostly WD 7200rpm) inside along with at least one, possibly two drive caddies and one optical drive ... so how do I get 9 sata ports out of a motherboard that only has 6 ??

I found this build list in a review of a Fractal case:

CPU: AMD Ryzen 9 3900X
Cooler: Fractal Design Celsius S36
Case: Fractal Design Define 7
Motherboard: Gigabyte X570 Aorus Elite
Memory: 32GB G.Skill TridentZ Neo DDR4-3600MHz
Graphics: Nvidia RTX 2080 8GB GDDR5
SSD: 1TB WD Black M.2 NVMe
Power Supply: Seasonic Focus PX-850 Platinum 850W

@xberk If you want more than 1 front panel accessible drive bay, you'll need the XL version of that case... I have the older one (pre-usbc) and it has 4, though I'm only using 2. One for a Pioneer sata blueray burner and the other for a Kingwin sata caddy that takes either regular sized sata drives or slim ones. The XL is about 3 inches taller. My newer shorter case, like the one you linked, only has 1 front panel drive slot where I have a Kingwin dual slim sata lockmount caddy. I use a usbc blueray drive on that system. Also have a Sedna usb3-to-sata cable to further lower the demand for sata ports. Both cases have removable frames for extra drives accessible by unscrewing the bottom side panel. But I took them out in favor of using provided sata-ssd mount points on the back side of the metal frame under the motherboard.

Regarding the use of 3600 ram... I've be careful with that. Make sure you burn in with prime95. I had to bump my 3600's down to 3400 to make it through the night error free. The cooler sounds... cool... if you get it I'd be interested in hearing your impressions.

Thanks everyone .. I think I can live with the Fractal Design 7 case .... considering the larger Design 7 XL too ... now for Graphic card .. The Gigabyte rx5700xt looks excellent and should not have a problem in the x570 Gigabyte mobo .. but will it run full out GPU acceleration on VP18 ? Anyone using the rx5700tx?

Thanks everyone .. I think I can live with the Fractal Design 7 case .... considering the larger Design 7 XL too ... now for Graphic card .. The Gigabyte rx5700xt looks excellent and should not have a problem in the x570 Gigabyte mobo .. but will it run full out GPU acceleration on VP18 ? Anyone using the rx5700tx?

The RX 5700 XT runs around $400 USD so for just $100 more you should be able to get a RTX 3070 when they have stock again... Maybe use an old GPU until you can find one of the latest GPUs...

Also, I like the idea of getting the 3950X up-front & saving money on something you can easily add later... If you go with the faster CPU, you won't have to worry so much about overclocking your DDR4, which is not a good idea if you eventually plan to have (4) sticks since (4) do not overclock as easily / as stable as just two...

The key is spending your money on stuff you cannot replace easily or add-onto later... You can add a 2nd M.2 stick, you can add 2 more sticks of memory, more SSD or SATA drives... However, if you upgrade the CPU, GPU, etc. you have to mess with removing re-selling the old one which always quickly become obsolete & lose value...

Focused on graphic cards .. the new RTX3080 is a bit more than I wanted to spend, but wouldn't an NVIDA card work better with Vegas? BUT .. this card is very new .. so information on it is hard to find .. AND the older RTX2080 is actually more money !! ..

Like most of us here I'm after the very best preview .. not so much worried about rendering speeds, it's timeline playback while fully loaded with audio and video FX .. I generally don't make proxy files .. still working in 1080p .. So for a smoother, better preview I would spend extra dollars .. BTW, my current card has about 300 CUDA, this new RTX3080 has something like 8000 ... if CUDA matters anymore ..

I have excellent full preview and other things in 4K AVC or HEVC on my 4K screen for Vegas Pro with my Nvidia 1660 Ti on desktop, not so expensive.😀

Focused on graphic cards .. the new RTX3080 is a bit more than I wanted to spend, but wouldn't an NVIDA card work better with Vegas? BUT .. this card is very new .. so information on it is hard to find .. AND the older RTX2080 is actually more money !! ..

Like most of us here I'm after the very best preview .. not so much worried about rendering speeds, it's timeline playback while fully loaded with audio and video FX .. I generally don't make proxy files .. still working in 1080p .. So for a smoother, better preview I would spend extra dollars .. BTW, my current card has about 300 CUDA, this new RTX3080 has something like 8000 ... if CUDA matters anymore ..

The 2080ti and the Vega 64, Radeon VII were really heads and shoulders above all other pro-sumer cards on playback, especially once you've employed any effects/crops etc. AND the 3080 is better performing, at least on paper, than the 2080ti, and as you mention, for half the money. Try to find some testing on that. (lot of difference between 2080 and 2080ti BTW, ti much faster, more expensive).

@fred-w .. that is my plan .. I think the RTX3080 looks worth it ... Problem may be getting my hands on one when I finally make up my mind ..

@xberk My private suggestion for video editing is a Intel CPU (for QSV support) and a NVIDIA (2/3)080 RTX (for NVDEC/NVENC support)... and to spread the performance on different devices. QSV and NVENC are stable and supported by VEGAS and all other video editing tools. In our internal tests we see a huge boost by the latest Intel CPU with onboard GPU in combination with NVIDIA.

@VEGASPascal  ... thank you so much for the comment. It makes me feel so much better because I took delivery a few weeks ago of a Dell Alienware desktop with a 10th gen i9 Intel CPU and an Nvidia 2080 Super GPU. And I'm getting 25 fps (or close to) on the TL with 4K in Best (Auto) unless there's a super intensive plugin added like some of BCC OFXs like noise reduction, and even then its about 15 fps.

@VEGASPascal  ... thank you so much for the comment. It makes me feel so much better because I took delivery a few weeks ago of a Dell Alienware desktop with a 10th gen i9 Intel CPU and an Nvidia 2080 Super GPU. And I'm getting 25 fps (or close to) on the TL with 4K in Best (Auto) unless there's a super intensive plugin added like some of BCC OFXs like noise reduction, and even then its about 15 fps.

Good choice for video editing and working with Ai... i9 with or without onboard GPU?

@xberk My private suggestion for video editing is a Intel CPU (for QSV support) and a NVIDIA (2/3)080 RTX (for NVDEC/NVENC support)... and to spread the performance on different devices. QSV and NVENC are stable and supported by VEGAS and all other video editing tools. In our internal tests we see a huge boost by the latest Intel CPU with onboard GPU in combination with NVIDIA.

@VEGASPascal
OH boy ... The journey continues .. I'll take another look at Intel CPU .. Frankly, I don't understand QSV or NVDEC/NVENC .. But along these lines, it seems the Ryzen 9 3900/50 supports PCI-E 4.0 while Intel is stuck at PCI-E 3.0 .. But what difference these things make to VP18 would be the point. Wish I understood it .. What got me was the mood out there has clearly shifted to Ryzen 9 3900/50 against comparably priced Intel CPU's .. but .. that mood is mostly coming from gamers and not specific to performance of VP18 .. So I will take another look at Intel CPU's ... thanks .. What I do understand is that chances are I will be happy with either CPU since either will run rings around my current setup.

@TheRhino .. >>The RX 5700 XT runs around $400 USD so for just $100 more you should be able to get a RTX 3070 when they have stock again... Maybe use an old GPU until you can find one of the latest GPUs...

Can you tell me if my old video card, GTX560ti will run with a new motherboard and cpu? All the new boards are at least PCI-e 3.0 ??

Onboard memory of the GTX560ti likely won't meet Vegas Pro 18 minimum requirements.

@john_dennis

Did some research and so far it seems that folks think that any PCI-E GPU will work in any PCI-E slot, including the on the x570 motherboard I'm contemplating. I'm using VP18 now on my old Windows 8.1 system with a LGA 2011 motherboard that uses PCI-E Gen 3 .. so maybe the old card will not be good enough for VP18 GPU acceleration (which I always leave turned off) but it should run VP18 .. I'd only do this if I have to wait a few months for a video card (like the RTX3080) ..