Question Zen 4 builders thread

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Kaluan

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Jan 4, 2022
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Can someone give any insights on if current crop of AM5 boards (that typically advertise 6400-6666MTs as a "up to DDR5 OC") could potentially do 7000MTs or more when say... 7000G series drops? Or could there be technical limitations (that I don't understand) potentially stopping the motherboards from sustaining high DDR5 speeds (despite hypotethically desktop Phoenix or future mainstream SKUs IMC/FLCK not being the bottleneck).

Asking for a friend (no joke lol)

Thinking of a B650M Mortar + Phoneix (no dGPU) + whatever best price/performance DDR5 you can scrounge around the end of this year.
 

lopri

Elite Member
Jul 27, 2002
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Highest memory frequency on this platform I have seen anywhere is Det0x's 6500 MT/s. Most others top out at 6400 MT/s.

I suspect it'll take a refresh line-up for higher frequency memory support. If AMD cares, that is. It seems to me AMD is focusing more on the idea of larger cache on desktop, which inherently negates slow memory disadvantage.
 
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cellarnoise

Senior member
Mar 22, 2017
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It can be a challenge with middle of the road 6000 EXPO RAM even to go much over 6000. I have this that I think has already been pushed to the limits from the factory as I can't seem to push it past 6100, though I have been able to tighten the timings some at 2033 fabric.


Don't forget that Det0x has spent a great deal of time testing both for the best RAM sticks and better cpu samples! They have found the best that has pushed the limits to the max from what I have seen after a fair bit of time trying to push my junk. I seem to have a 7950x that has good CPU cores all around, but not a great IOD...

I think I am done playing with the RAM as I have burned up too much time already playing around!!! The long memory training has taken some of the fun out of this also :)
 
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Thor86

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May 3, 2001
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Kaluan

Senior member
Jan 4, 2022
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Highest memory frequency on this platform I have seen anywhere is Det0x's 6500 MT/s. Most others top out at 6400 MT/s.

I suspect it'll take a refresh line-up for higher frequency memory support. If AMD cares, that is. It seems to me AMD is focusing more on the idea of larger cache on desktop, which inherently negates slow memory disadvantage.
Oh yeah I understand that. But I know that's more of the case of Raphael IMC/fclk being limited, be it by silicon, microcode maturity or just straight up architectural walls.

What I was wondering is if the motherboards can take it. Future monolithic chips and Granite Ridge (& successors) will obviously have higher headroom and sweet spots.
Wouldn't it be sad if when you plop your 8700G or 8900X in 2 years from now, you find out your X670E ROG Hero can barely do 6600MT. But your friend's B750M Pro can do 7200MT without breaking a sweat? lol
 

igor_kavinski

Diamond Member
Jul 27, 2020
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Wouldn't it be sad if when you plop your 8700G or 8900X in 2 years from now, you find out your X670E ROG Hero can barely do 6600MT. But your friend's B750M Pro can do 7200MT without breaking a sweat? lol
That's why they would expect you to buy the newer chipset and hand down your expensive one to someone who doesn't really care about the memory speed. I honestly don't trust statements from AMD anymore. They kept saying before Zen 4 launch that memory overclocking is looking really good which kinda made us think that it would be on par with Alder Lake or even Raptor Lake. But no, doing even 6100 MT/s is no easy task, let alone 6400 MT/s.
 
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lopri

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Jul 27, 2002
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Edit: I wrote a nonsensical theory-crafting and deleted it. I am still unsure how much bandwidth the Infinity Fabric can handle between CPU and memory.
 
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Hans Gruber

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Dec 23, 2006
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That's why they would expect you to buy the newer chipset and hand down your expensive one to someone who doesn't really care about the memory speed. I honestly don't trust statements from AMD anymore. They kept saying before Zen 4 launch that memory overclocking is looking really good which kinda made us think that it would be on par with Alder Lake or even Raptor Lake. But no, doing even 6100 MT/s is no easy task, let alone 6400 MT/s.
AMD said their Zen4 processors would shine in OCing memory. I know we all thought, this is great. Fast memory means much better performance. Like Zen 3 that topped out at 3800mhz and maybe 4000mhz in some cases. Zen 4 has already topped out it seems with DDR5 with what 6400 MT/s in very best case scenarios. WTF? Memory makers are boasting about DDR5-8000 kits that already exist but are sold out.

I am getting closer to jumping on the Zen 4 train. Probably another 6 months out. It seems that latency is more important then the speed of the sticks. The problem is when the speed of the memory is already maxed out on DDR5 and that memory platform is just getting started.
 

Hans Gruber

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Dec 23, 2006
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Chiplets will always have disadvantage. APUs (5600G, 5700G) can easily clock DDR4 above 4000 MT/s.
Of course they can but then you run into the memory divider issue which introduces massive amounts of latency offsetting the increased frequency clock of the memory.

I do not have Zen 4. Does the same memory divider issue exist on Zen 4?
 

lopri

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Jul 27, 2002
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You can use divider but there is no reason to at the moment because all Zen 4 memory controllers can do 3000 MHz and that works with DDR5-6000. Depends on CPU/board/memory you can do up to DDR5-6400 1:1 and it comes to an abrupt cliff. Not sure where exact limit lies, it's either the Infinity Fabric or the memory controller. Presumably memory controller should be able to do mclk/2 mode beyond DDR5-6400, so I am leaning to believe that it is the IF.
 

IEC

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Super Moderator
Jun 10, 2004
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I will say at the comparative point in the lifecycle of AM4 compared to AM5... AM4 was significantly less polished.

Just as with AM4 though, I expect the platform will really show its shine in the later years. I still have a X370 board running a Zen 3 chip in a friend's rig... and running Zen 3 on a X470 board myself.

I fully expect as with 5800X3D the 7000X3D parts will be less sensitive to memory tuning. Which is why I bought cheap DDR5-5600 CL36 memory. I'm happy the astoundingly overbuilt X670E boards and platform pricing forced price cuts so early though, as it made my price for entry cheaper than AM4 despite higher mobo pricing.

Comparison of costs (AM4 launch adopter vs AM5 early adopter):
CPU 1800X - $500 vs 7700X - $340
Mobo - $200 vs $350 (X370 vs X670E)
RAM - $180 vs $130 (DDR4-16GB 3200 vs DDR5-32GB 5600)

Total: ~$880 (AM4) vs ~$820 (AM5)
 

CP5670

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Jun 24, 2004
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There is also B650E, which seems similar to X670E but $150 or so cheaper for a similar type of board. It's not as big a gap as previous chipsets. The only issue is there are fewer board choices for that platform.
 
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Timmah!

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Jul 24, 2010
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Just found this on reddit:

https://www.reddit.com/r/nvidia/comments/10bxhhy
since i am about to have 2x GPUs, one of them being actual Suprim Liquid and the other one (air cooled 3,5 slot) Gigabyte Gaming, would you guys mount one card like this (probably the Gigabyte though) and then the other one in vertical position? Not quite sure, but it seems to me, they might not interfere with each other in such positions. Question is, would it be better solution than mount them both regularly without risers, with 2 slots inbetween them and bottom line half slot above PSU shroud?
 
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lopri

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Jul 27, 2002
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Both without risers, the liquid version at the top slot, would be my choice for cooling performance. It's probably not a pretty setup, though. You can move them around and test it out. I think you will find out quickly what works best.
 

CP5670

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Jun 24, 2004
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The MSI card's radiator should be an exhaust and preferably top mounted. It may be better to have the Gigabyte card on top, so it doesn't dump all its heat on the other card.
 
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itsmydamnation

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Feb 6, 2011
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AMD said their Zen4 processors would shine in OCing memory. I know we all thought, this is great. Fast memory means much better performance. Like Zen 3 that topped out at 3800mhz and maybe 4000mhz in some cases. Zen 4 has already topped out it seems with DDR5 with what 6400 MT/s in very best case scenarios. WTF? Memory makers are boasting about DDR5-8000 kits that already exist but are sold out.

I am getting closer to jumping on the Zen 4 train. Probably another 6 months out. It seems that latency is more important then the speed of the sticks. The problem is when the speed of the memory is already maxed out on DDR5 and that memory platform is just getting started.
Just run tighter timings, people get this odd idea that memory bandwidth is the super important metric , for the majority of workloads especially gaming it isn't, latency is.
 

Hans Gruber

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Dec 23, 2006
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Just run tighter timings, people get this odd idea that memory bandwidth is the super important metric , for the majority of workloads especially gaming it isn't, latency is.
Even with DDR4 memory. Running tight timings Cas 14 or Cas 16 will smoke DDR4 3200mhz if you run Cas 16 at 3600mhz+. Yes tighter timings make sense but as the DDR5 memory matures. If 8000mhz sticks are cheap and readily available. 6000mhz DDR5 sticks with tight timings will not be able to compete with 8000mhz and above DDR5 regardless of their timings.

Tight timings cannot overcome bandwidth benefits with faster memory sticks. AMD said that Zen 4 would be an OCer's dream. Now I am heard DDR5 6400mhz is asking too much. Like Zen 3, it may just need a bios update. My original B350 motherboard runs DDR4 16-20-20-20 @ 3800mhz.

If the current Zen 4 motherboards can support DDR5 8000mhz with a bios update. Then people will have nothing to worry about. Otherwise we will have to listen to Intel fans talking about fast DDR5 (8000mhz) being for Intel builds only.

This is the only forum that is pro intel in such a way that they deny Raptor Lake being excellent. My only complaint about Intel is that I am waiting for the Intel 4 (7nm silicon). With the release of the 7900 @ 65w. I have no problems with AMD. Energy efficiency is something I value over top line performance. The AMD motherboard pricing gives me pause.
 

Hans Gruber

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Dec 23, 2006
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I think the mobo makers really disliked releasing AM4 BIOS updates so now they are charging ahead of time for that "incovenience" with AM5.
I have always said and thought that ram is ram. Remember when they had/still have AMD specific ram? Then the B450 fixed the ram issues. Then AMD said the B350/X370 boards would not support Zen 3. Then they issued bios fixes so that there were no memory restrictions with B350/X370 motherboards. Then they updated the AGESA bios to support Zen3 on the original AM4 motherboards.

I know there has been a number of trust issues violated. Too many make excuses for AMD. Bios updates take forever but are always fixed. Intel says, don't worry about it. When you buy your next CPU and motherboard, those issues will be fixed in the next generation.

Quick question, did I pay too much for my Asus B450-F @ $90 brand new? Did I pay too much for my top of the line MSI B350 Carbon Gaming Pro motherboard @ $80 4+ years ago?

Lastly, I like that AMD supports motherboards for many years and many generations. If Intel 4 (7nm) hits above it's weight. Remember I said this is Intel we are talking about. They don't like to lose for long. Will AM5 justifiers of $250-300 motherboards look foolish if Intel wipes the floor with AMD moving forward? In 2 years will Intel be 30% above AMD in IPC with the same or similar core counts? If so, there goes justifying the inflated costs of AMD motherboards.

On the positive side. AMD has always been masterful at pricing their products up against better or slightly better competition. When AM4 was first released all the reviews raved about the cheap AMD motherboards and the entry point for AM4 systems though inferior offered a lot of value.


I speak for the computer market. AM4 CPU's are selling great right now compared to the AM5 Zen 4 processors. I won't even start a GPU argument and question the logic and reasons for AMD pricing. Like why is the 6800xt not $300 today?
 
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Timmah!

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Jul 24, 2010
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Both without risers, the liquid version at the top slot, would be my choice for cooling performance. It's probably not a pretty setup, though. You can move them around and test it out. I think you will find out quickly what works best.
OK. It wont be pretty for sure :), if only because the GPUs are not matched - it literally hurts my OCD. But if i picked 2 watercooled ones, there would be no place for the third radiator (aside of the bottom, which is not good) and anyway 3 AIOs in one case i guess is over the top - at that point you shall be doing custom loop and i was not ready to do that. If i picked 2 air-cooled ones, with their massive 3,5 coolers, there would be once again half slot between them and the upper one hot as hell.

The MSI card's radiator should be an exhaust and preferably top mounted. It may be better to have the Gigabyte card on top, so it doesn't dump all its heat on the other card.
I intended to mount the MSI rad upfront as intake (with another 14cm fan underneath as one more intake), CPU rad (Arctic 420) to the roof as exhaust, then one more 14cm fan in the back as exhaust and 2 more 14cm in the bottom as intakes. You think i should i swap the positions of GPU and CPU rads?
 

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