RAM GHZ + MOBO

[Dagosmike88]

Hi I am very curious and not quite sure how to ask this in google to be short enough for it to narrow it down. What I wanted to know is RAM speeds are determined by what the MOBO allows I got that. I have an ASUS crosshair viii dark hero and I believe it claims speeds up to 5100ghz. My RAM is 4000ghz corsair pro 16x4. I tried going into the BIOS to increase the RAM speeds to 4000ghz since they came out the box at 3200ghz. I have only been able to set them at 3600ghz and anything over that when I boot up with saved changes my pc shuts off and on off and on. So to be clear i have 64g of RAM and 4 sticks. If i was to say remove 2 sticks would that allow me to increase the RAM speeds further? Like if there is a power allowance for the amount of sticks used. Maybe this question is stupid and easy or obvious to others but I honestly want to understand this and the only way to find out how to word it to click into my head. A bit difficult to explain or maybe just seems complicated to myself cause I'm kind of an idiot. 

[PDifolco]

The CPU can also limit RAM max clock speed, what's yours ?

[Dagosmike88]

10 minutes ago, PDifolco said:

The CPU can also limit RAM max clock speed, what's yours ?

5900x

[SavageNeo]

11 minutes ago, PDifolco said:

The CPU can also limit RAM max clock speed

depends on the IMC, which is game of luck, RNG and crying.

[Fasauceome]

16 minutes ago, Dagosmike88 said:

I have only been able to set them at 3600ghz and anything over that when I boot up with saved changes my pc shuts off and on off and on.

are you setting only the speed manually, or are you using an XMP profile? Are you customizing the voltage and timings?

[Hairless Monkey]

14 minutes ago, Dagosmike88 said:

My RAM is 4000ghz corsair pro 16x4.

That's a lot of RAM. It'll be challenging to get the Integrated Memory Controller(IMC) in the CPU to run that fast with that much RAM.

15 minutes ago, Dagosmike88 said:

I tried going into the BIOS to increase the RAM speeds to 4000ghz

That is not how you do that. To run the RAM at it's rated speed, you must go into the BIOS and enable the XMP setting.

16 minutes ago, Dagosmike88 said:

If i was to say remove 2 sticks would that allow me to increase the RAM speeds further?

Yes.

 

16 minutes ago, Dagosmike88 said:

Like if there is a power allowance for the amount of sticks used.

But not for this reason. Higher capacities allow for more parallelization of memory operations, which puts more strain on the IMC. So removing two sticks may allow for higher speeds, but may not result in actually faster memory bandwidth.

[Dagosmike88]

1 minute ago, Fasauceome said:

are you setting only the speed manually, or are you using an XMP profile? Are you customizing the voltage and timings?

i believe i have the amd version of xmp settings enabled. think it was d.o.c.p? as for voltage i dont think so thats not really something i know much about.

[PDifolco]

7 minutes ago, Dagosmike88 said:

5900x

Ok, it should allow 4000MT but you won't get much of an improvement over 3600 unless you overclock the Infinity Fabric....

Try with 2 sticks 

[Fasauceome]

1 minute ago, Dagosmike88 said:

i believe i have the amd version of xmp settings enabled. think it was d.o.c.p? as for voltage i dont think so thats not really something i know much about.

For a really fast ram kit, you usually will want to increase voltage to get better stability. Is the system stable with DOCP enabled and the memory speed set to 3733?

 

Keep in mind, memory speed isn't the end all be all. With Ryzen, you need to increase the fclk as well to compensate. Memory speed settings below 3800 will automatically set the fclk to half the rated speed of the ram, but above that you will need to manually tune it, otherwise you'll have latency introduced and you'll actually lose performance.

[Dagosmike88]

xmp is for intel correct? and d.o.c.p is amds varient? if thats the case i have enabled that and it does auto set it to 4000 but it crashes till i manually set it to 3600. 

so to clarify i remove 2 sticks of ram then it could allow me 4000ghz or? sorry your comment is helpful but like i said im kind of an idiot lol. difficulty fully grasping everything.

[Dagosmike88]

3 minutes ago, PDifolco said:

Ok, it should allow 4000MT but you won't get much of an improvement over 3600 unless you overclock the Infinity Fabric....

Try with 2 sticks 

ok 

[Somerandomtechyboi]

Sorry but that board is abysmal, asus have horrifically bad ram topology on b550 and x570 so dont expect >4000, though shouldnt be a problem for slower speeds

 

i assume the sticks are single sided so its still a dual rank config like you would get buying 2x32 dual sided sticks which means ~20% banwidth increase vs single rank, i suggest checking out thaiphoon burner for your ram ic and you can send a pic here to verify what ic it is, its most likely micron 16gbit rev b which is very light on the imc, then clock it up to 3733 or 3800 (sync infinity fabric cause no way that pos board can run >4800 esp not dual rank 4 stick config and ludicrous speed dont have much advantages in the first place vs the effort needed to tune em, i/f usually 1866-1933 for 2 ccd ryzens)

[Dagosmike88]

1 minute ago, Fasauceome said:

For a really fast ram kit, you usually will want to increase voltage to get better stability. Is the system stable with DOCP enabled and the memory speed set to 3733?

 

Keep in mind, memory speed isn't the end all be all. With Ryzen, you need to increase the fclk as well to compensate. Memory speed settings below 3800 will automatically set the fclk to half the rated speed of the ram, but above that you will need to manually tune it, otherwise you'll have latency introduced and you'll actually lose performance.

would be nice to learn that but does that have any of that bs like silicon lottery where what it can handle isnt set in stone from the manufacturer like cpu? is there a good set ratio for power and speed or does that all depend on each individual build?

[Fasauceome]

Just now, Dagosmike88 said:

would be nice to learn that but does that have any of that bs like silicon lottery where what it can handle isnt set in stone from the manufacturer like cpu? is there a good set ratio for power and speed or does that all depend on each individual build?

All OC related stuff is silicon lottery. You only get what the manufacturer tells you that you get on the tin. Ratio for best speed is "1:1", where the memory speed is in line with the fclk (DDR means your listed memory speed will be twice the true operating frequency) whereas any proportion of faster ram than fclk is denoted as "2:1" which is not favorable.

 

Even though you said in your original post that you'd like to get your memory speed to 4000MHz or higher, if your fclk can't reach 2000MHz and remain stable, you'd see worse performance despite the faster memory.

[Eigenvektor]

2 minutes ago, Dagosmike88 said:

xmp is for intel correct? and d.o.c.p is amds varient?

Yeah, people just generally say XMP to mean either.

 

2 minutes ago, Dagosmike88 said:

if thats the case i have enabled that and it does auto set it to 4000 but it crashes till i manually set it to 3600. 

so to clarify i remove 2 sticks of ram then it could allow me 4000ghz or? sorry your comment is helpful but like i said im kind of an idiot lol. difficulty fully grasping everything.

As was said above, four sticks is harder for the IMC to run than two sticks, so removing sticks might make that possible, yes. No guarantees though.

 

Faster speeds have diminishing returns and for gaming you generally want lower latency rather than higher frequency. There's also the issue that Zen 3's Infinity Fabric (IF) generally doesn't like to run over 1900–2000 MHz, which roughly translates to 3800–4000 MT/s for RAM. If you go beyond that it'll switch to 1:2, so you might get faster RAM speeds but actually lower IF speeds. Might want to run some benchmarks before/after, so see if you're gaining anything worthwhile.

[Dagosmike88]

1 minute ago, Somerandomtechyboi said:

Sorry but that board is abysmal, asus have horrifically bad ram topology on b550 and x570 so dont expect >4000, though shouldnt be a problem for slower speeds

 

i assume the sticks are single sided so its still a dual rank config like you would get buying 2x32 dual sided sticks which means ~20% banwidth increase vs single rank, i suggest checking out thaiphoon burner for your ram ic and you can send a pic here to verify what ic it is, its most likely micron 16gbit rev b which is very light on the imc, then clock it up to 3733 or 3800 (sync infinity fabric cause no way that pos board can run >4800 esp not dual rank 4 stick config and ludicrous speed dont have much advantages in the first place vs the effort needed to tune em, i/f usually 1866-1933 for 2 ccd ryzens)

yea some of this stuff with the board kinda clicked in my head recently and before i was kinda just buy the most expensive thats available to me at the moment. so yea i kno its not the most expensive but in my area within reach it was lol. i do understand price dont mean shit now but like the ram question i had theres others that havnt clicked yet. i enjoying building pcs but i really wanna understand them fully to be able to build the best build for what i like.

[Dagosmike88]

4 minutes ago, Eigenvektor said:

Yeah, people just generally say XMP to mean either.

 

As was said above, four sticks is harder for the IMC to run than two sticks, so removing sticks might make that possible, yes. No guarantees though.

 

Faster speeds have diminishing returns and for gaming you generally want lower latency rather than higher frequency. There's also the issue that Zen 3's Infinity Fabric (IF) generally doesn't like to run over 1900–2000 MHz, which roughly translates to 3800–4000 MT/s for RAM. If you go beyond that it'll switch to 1:2, so you might get faster RAM speeds but actually lower IF speeds. Might want to run some benchmarks before/after, so see if you're gaining anything worthwhile.

thanks for the info will try. i think i seen some videos before sayin that amd cpus perform better with high speed ram? guess i misunderstood.

[Eigenvektor]

6 minutes ago, Dagosmike88 said:

thanks for the info will try. i think i seen some videos before sayin that amd cpus perform better with high speed ram? guess i misunderstood.

While that's generally true, there's a practical limits to how much you really need, and as was said, if your IF switches to 2:1, you'll likely even lose performance. It was much more important for Zen 1+2 and also for APUs with an integrated GPU. Zen 3 has a better cache, making it less important. Also, anything ≥3200 MHz typically counts as "fast".

 

Anything beyond that is not really worthwhile in most cases, you're paying much more for ever smaller increases in performance. Depending on what you're doing (e.g. gaming) you'll get much more out of 3200 MHz with CL 14, than you'll get out of 4400 MHz with much higher latency.

[Somerandomtechyboi]

5 hours ago, Dagosmike88 said:

yea some of this stuff with the board kinda clicked in my head recently and before i was kinda just buy the most expensive thats available to me at the moment. so yea i kno its not the most expensive but in my area within reach it was lol. i do understand price dont mean shit now but like the ram question i had theres others that havnt clicked yet. i enjoying building pcs but i really wanna understand them fully to be able to build the best build for what i like.

Yea rip, you arent safe from getting garbage even if you pay top $, though this is just an asus issue, their intel boards even the older amd ones dont suffer from abysmal ram topology so you are fine with choosing asus, the price can be ridicolous while competitiors outspec it though so avoid asus unless you get a good deal imo

 

 

Ram dont really matter that much so i dont think you should care that much about ram oc, the board is horrifically bad for ram oc but slow <4000 should be fine cause otherwise ppl would be crapping on asus left and right. Just stick with 3600 but if you want that 1-2% gain you can oc to 3733 - 3866 depending on cpu fclk ability, youd prob get far more gains by just tightening important subtimings like trfc, sr dr and dd, maybe also some other stuff like twr, trc, etc. still only ~5% but its 5% without cranking the freq to the moon, these kits usually come with abysmal subtimings so youll get a decent bit of performance by just tightening them, also trefi to 65536 incase the rams dont do that stock since that also boosts performance. Primaries are kinda unimportant for performance but tighten them if you want, just avoid tightening cl since thats one of the most painful timings to get stable and also needs volt, you can likely just set cl16 at 3600-3866 so just leave it at that and dont go any tighter to not heat up the rams, ram heat isnt an issue most of the time other than >1.5v shenanigans and/or high freq shenanigans, keep the ram temp low just to have some headroom for higher ambients and stuff so it doesnt destabilise when ambient temp is high

 

if you just wanna lazy oc there should be plenty of 3200-3800 profiles for your ram ic so check in thaiphoon burner, most 16gbit stuff can do atleast 4000 even the hynixes