What is the fastest ram I can put in all 4 slots on ASUS X570 Crosshair VIII Here?

[Aaralli]

I'm about to buy parts for a new gaming/video editing PC, and I'm wondering what the absolute fastest RAM I can use is. I'm planning on using an ASUS X570 Crosshair VIII HERO WiFi, Ryzen 9 5900X, RTX 2070 Super (saving for an upgrade, already have this card), and at least 32GB of RAM. I like having all 4 ram slots populated because it looks better IMO, so what's the fastest RAM I should buy that can be used in all 4 slots? I know some boards have two fast slots and two slower ones but I couldn't find an actual rated top speed.

 

By the way, if it's actually better to just use two RAM sticks in the two main slots, I'm fine with that if I can get it faster but I would definitely like to know my options. Also is it worth going over 3600Mhz if the FCLK of the CPU likes to be at 1800mhz?

[Motifator]

Not a good idea with anything Ryzen, I always say this; Zen is traced to run the most reliably and fast with this leading config... the 2nd and the 4th slot. If you own any Ryzen setup, never forget this. Always have 2 sticks and plug them to the 2nd and the 4th slots, because that's how the platform is built from ground up to perform properly.

I recently picked up a 5900X with some spare cash to upgrade from a 3900X, I'm running it at almost 4.8 all core, but the RAM is just at 3733. 

The ram should be at a 1-1 ratio, so at most I'd buy 4000 RAM and downclock it to 3800. That means 1900 FCLK if you're able to pull it off.

[RONOTHAN##]

5 minutes ago, Aaralli said:

ASUS X570 Crosshair VIII HERO WiFi, Ryzen 9 5900X,

If you don't own either of these, it probably doesn't make sense to get them over a 13th gen Intel setup, a 13600K is significantly faster in pretty much everything while being cheaper (and the same price as the 5900X is on the second hand market). If you're getting them for cheap from a friend, that's one thing, but buying them new is not a great decision. 

 

7 minutes ago, Aaralli said:

so what's the fastest RAM I should buy that can be used in all 4 slots?

If you do get that board, 3733MT/s should be reliable with 4 DIMMs. 

 

8 minutes ago, Aaralli said:

Also is it worth going over 3600Mhz if the FCLK of the CPU likes to be at 1800mhz?

Basically every Ryzen 5000 series CPU does 1900MT/s FCLK, so in a perfect world you'd be running 3800MT/s RAM. Good luck finding a 4x8GB kit rated at 3800MT/s though.

 

There can sometimes be a point to running really high memory frequency and desyncing the infinity fabric, but it's pretty conditional. 

[Shimejii]

You wont notice any difference going above 3600. Quite literally you will not notice it, people that say otherwise are just being dishonest. 

 

Stick with 3600 or 3200 for stability, but do be warned 4x16 can be potentially unstable at the higher speeds. If you dont already have the 5900x and MOBO, i would strongly consider 13th gen or 7000 series ryzen. But it all comes down to what your paying for it.

[An0maly_76]

Don't be so concerned with what's fastest, be more concerned with what will be stable. Stability issues are common with certain RAM and processor combinations on certain boards. Be mindful of your board manufacturer's QVL per the series processor (Matisse, Renoir, Vermeer, etc.).

[Aaralli]

2 hours ago, RONOTHAN## said:

If you don't own either of these, it probably doesn't make sense to get them over a 13th gen Intel setup, a 13600K is significantly faster in pretty much everything while being cheaper (and the same price as the 5900X is on the second hand market). If you're getting them for cheap from a friend, that's one thing, but buying them new is not a great decision. 

 

If you do get that board, 3733MT/s should be reliable with 4 DIMMs. 

 

Basically every Ryzen 5000 series CPU does 1900MT/s FCLK, so in a perfect world you'd be running 3800MT/s RAM. Good luck finding a 4x8GB kit rated at 3800MT/s though.

 

There can sometimes be a point to running really high memory frequency and desyncing the infinity fabric, but it's pretty conditional. 

 

2 hours ago, Shimejii said:

You wont notice any difference going above 3600. Quite literally you will not notice it, people that say otherwise are just being dishonest. 

 

Stick with 3600 or 3200 for stability, but do be warned 4x16 can be potentially unstable at the higher speeds. If you dont already have the 5900x and MOBO, i would strongly consider 13th gen or 7000 series ryzen. But it all comes down to what your paying for it.

Honestly, I can't ever buy Intel chips or boards. I've had this grudge against Intel for over a decade now and I'm only 21 years old (very long story best saved for another day). I'll likely be stuck with AMD processors forever, although I do build Intel systems for other people or use old Intel chips when I get them for free.

 

On another PC I use regularly I have a Ryzen 9 3950X with 4x8gb of Corsair Vengeance RGB Pro 3600 MT/s CL18, and that's the fastest I've ever owned. If not the absolute top speed, what speed should I realistically be looking for?

 

I'm not interested in "desyncing" the infinity fabric. I'd never heard of it running at 1900mhz on 5000 series CPUs though. I guess I just assumed that they ran at the same speed as 3000 series.

[RONOTHAN##]

3 minutes ago, Aaralli said:

I'd never heard of it running at 1900mhz on 5000 series CPUs though. I guess I just assumed that they ran at the same speed as 3000 series.

Even on 3000 series, most of the chips did 3733MT/s fully synced. AMD lists the "sweet spot" at 3600 since that's what 99% of CPUs could do infinity fabric wise, plus memory kits at 3733MT/s or 3800MT/s are very rare. They did up that advertised "sweet spot" to 3733MT/s for Ryzen 5000, though again, there are very few kits with an XMP of that speed so everyone just stuck to 3600MT/s for XMP speeds.

 

8 minutes ago, Aaralli said:

If not the absolute top speed, what speed should I realistically be looking for?

Realistically there isn't a ton of reason to go for anything faster than 3600MT/s CL18, and even 3200MT/s CL16 isn't that much slower. Spending the money on a higher rated kit (something like 3600 CL14) just doesn't make a whole lot of sense when DDR5 is starting to take over. Realistically going AM4 in general doesn't make a whole lot of sense, even if you have a grudge against Intel (fair enough, your money and everything, though I will point out with how fast things move in this industry grudges aren't really applicable after like 2-3 years), AM5 also exists, and while a fair bit more expensive than AM4 gear, a R7 7700X is still faster than a 5900X in productivity situations, and you picked a board that's expensive enough that AM5's high board cost (the biggest disadvantage on AM5) isn't really applicable, even if you want to go for a good board like a B650E Master or Strix B650E-E. 

[Aaralli]

15 minutes ago, RONOTHAN## said:

Even on 3000 series, most of the chips did 3733MT/s fully synced. AMD lists the "sweet spot" at 3600 since that's what 99% of CPUs could do infinity fabric wise, plus memory kits at 3733MT/s or 3800MT/s are very rare. They did up that advertised "sweet spot" to 3733MT/s for Ryzen 5000, though again, there are very few kits with an XMP of that speed so everyone just stuck to 3600MT/s for XMP speeds.

 

Realistically there isn't a ton of reason to go for anything faster than 3600MT/s CL18, and even 3200MT/s CL16 isn't that much slower. Spending the money on a higher rated kit (something like 3600 CL14) just doesn't make a whole lot of sense when DDR5 is starting to take over. Realistically going AM4 in general doesn't make a whole lot of sense, even if you have a grudge against Intel (fair enough, your money and everything, though I will point out with how fast things move in this industry grudges aren't really applicable after like 2-3 years), AM5 also exists, and while a fair bit more expensive than AM4 gear, a R7 7700X is still faster than a 5900X in productivity situations, and you picked a board that's expensive enough that AM5's high board cost (the biggest disadvantage on AM5) isn't really applicable, even if you want to go for a good board like a B650E Master or Strix B650E-E. 

Thank you, you've been very helpful. I think I'll go with 3600 mt/s in whatever latency I find first. The reason I'm going with older stuff is, I have a guy who repairs broken pins on CPUs and other "broken" but easy(ish) to fix PC components and I get my selection of parts from his wares whenever I see fit. Not much AM5 or DDR5 gear has been broken yet.