Hello people of Reddit,
I am planning to upgrade from my Intel Core i7-4790K to an AMD Ryzen 9 3900X very soon (I will not wait for 4th gen Ryzen!) and I have been browsing the web regarding this CPU and Ryzen over all. Benchmarks clearly show that AMDs CPUs outperform Intels CPUs not only in price/performance but also in high end performance too.
But I have come across the term "infinity fabric" regarding RAM speeds. As I understood it you want to keep the ratio between infinity fabric clock and RAM clock as simple as possible so 1:1 would be the most optimal but since the infinity fabric clock cant get much faster than 1900MHz when overclocking it at least for the Ryzen 3000s. Most people say that 3600MHz is the optimal RAM speed for Ryzen and can increase performance dramatically. Obviously the infinty fabric should be clocked at 1800MHz if we use 3600MHz RAM so we at least get a 2:1 ratio, which both yields high RAM speeds but also has a really simple infinity-fabrick-clock/RAM-clock-ratio rather than a 209/234-ratio.
Now since going for 3600MHz RAM seems to be an obvious choice how about voiding warranty? AMD claims their R9 3900X can handle RAM speeds up to 3200MHz. Since using 3600MHz RAM would mean that I use my CPU outside of the manufacturers specs this should void my warranty which could be quite important too keep at least for the first few months.
Now my 2 questions:
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Regarding Linus Tech Tips (https://youtu.be/iHJ16hD4ysk?t=436) 3600MHz is the best choice for performance - while exceeding the manufacturers specs - does this void warranty or do I need to do driect canges to my CPU to void the warranty?
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How realiable is running 3600MHz RAM on a 3rd gen Ryzen in the first place?
Thank you for reading till here, I really appriciate your help.
Regarding your question, I run a R5-3600 with 3600MHz ram overclocked to 3900MHz with infinity fabric (or sometimes your bios lists it as FCLK) clocked at 1900MHz.
DDR4 is Double Data Rate, and DDR memory can send and receive signals twice per clock cycle.
In English, that means that the listed spread of your ram is double the actual frequency- DDR4-3600 would be running at 1800MHz, DDR4-3733 would be running at 1867MHz, and so on. So you are still getting a 1:1 ratio between RAM speed and Infinity Fabric speed, even if your RAM speed is greater than 3600MHz, but sometimes a manual infinity fabric overclock is required in the bios, or in AMD Ryzen Master. I personally prefer the bios option.
So if I can run 3800MHz ram and 1900MHz FCLK on a Ryzen 5, 3600MHz ram on a Ryzen 9 should be no problem. And RAM needs to be overclocked to reach its rated setting anyway- for instance a kit of DDR4-3000 would be running at 2133/2400/2666MHz out of the box, and would require an XMP/D.O.C.P overclock to actually reach 3000MHz. After that you work your way up from their finding your highest stable overclock- I personally couldn’t get past 3866MHz at 1:1 between FCLK and MCLK without a blue screen and restart.
just made the switch myself. Overclocking is quite different from intel. I have actually decided against any cpu overclock. With the new amd stuff, to overclock you use PBO (precision boost override) This does overclock the processor, but all the cores, at a fairly high voltage, all the time, for a much better multi threaded speed. But at a high cost. You actually loose performance on lighter tasks (read gaming) as the processor would be able to self overclock (at stock) single cores at higher speeds. Then there is temperatures. Stock settings allow it to down volt and underclock constantly. Overclocked is high voltage all cores full time. And chip degradation. You can slowly cook these things with even "mild" over clocks.
If you need better multi threaded performance, over clocking is useful, but you would be way better off getting more cores instead.
As for memory speeds, I do run 3600mhz with no changes other than enabling xmp (D.O.C.P really) with a 1:1 ratio. This does not require a cpu overclock. This ram was on the QVL list for my motherboard at its rated speed.
Hi everybody,
I'm super new to this new amd exciting world of over clocking.
My rig is a 7800x3d on a asus b650e-f with 6000mhz at 32gb.
I just downloaded OCCT and I had noticed my IF (infinity fabric) is running at 1796mhz.
To point out, my bios has been updated and my bios setting is base outta the box with expo off.
My question is if my memory speed is actually 3000mhz, and the IF only handles half that, is it possible to running my ram kit at the 1796 or what ever bios setting allows close to this number, will it be stable?
This is all theory, let's talk about it!
Hey all:
This is really for my own information more than anything else; I don't have a pressing technical problem, but this issue has bothered me intellectually for some time, and I can't seem to find any articles that directly addresses it (maybe I'm just not searching for the right terms).
What determines the capacity, speeds, and populated slots that a given Ryzen CPU can support, and why? For example, it is commonly repeated that as you go up in total RAM capacity (from 2x8 to 2x16), you can expect your supported speeds to drop, and you may even need to loosen your timings. Why? This is doubly compounded if you go to even larger capacities or more physical sticks of RAM (2x32, 4x16, etc). Dual rank and single rank chips seem to play a role in this as well, but I'm not sure *what* role they play, only that the rank seems to matter. Does memory rank matter? If so, why?
I've heard it said that because the memory controller is onboard the CPU (Infinity Fabric), it's really the quality of your silicon that determines your luck with memory capacity, speed, and timing. Is this true? I've also read that your motherboard's power delivery can make a big difference too (though I'm not sure why that would be the case; RAM is, to my knowledge, not a substantial source of power draw). Does that also play a role? How and why?
Memory support/performance appears to have improved with each successive generation of Ryzen (Zen was the most finicky, Zen+ had major improvements in RAM compatibility, Zen 2 was even better, etc), but I still don't grasp the nuance (or the rationale) behind how these four RAM variables--speed, capacity, timing, # of sticks--are influenced by the CPU and/or motherboard. Any insight would be greatly appreciated.
EDIT: Thank you all for your responses thus far; this has been highly educational! I have some more reading to do, but now I understand what sorts of things I need to google in order to better understand.
Computer Type: Desktop
GPU: Powercolor Hellhound 7900XTX
CPU: RYZEN 7800X3D
Motherboard: ASRock B650 Livemixer
BIOS Version: The latest one off their website as of yesterday
RAM: 32GB G.Skill 6000MT/s DDR5
PSU: Corsair RM1000x
Case: Coolermaster
Operating System & Version: WINDOWS 11 Pro
GPU Drivers: 23.10.2
Description of Original Problem: I have enabled XMP on the RAM to run at the advertised 6000MT/s and my understanding is the infinity Fabric should ideally be half this. However when I set it to 3000 the PC won't post and I have to reset the CMOS to get it to POST again.
Troubleshooting: Ive read a bit on the infinity Fabric being a little unstable on these higher speeds - I was wondering if it is better performance wise to run the RAM at 4800MTs instead and keep the infinity Fabric at 2400 where it seems happy to run, or still run the RAM at XMP with the infinity Fabric not running at its optimum ratio?
With DDR modules now reaching 4000+Mhz, would it be feasible to start setting IF at a 1/3 speed, vs 1/2 of the ram? Eg: On 3600Mhz RAM running IF at 1200Mhz vs 1800? I have 1 ryzen 3900x, and 1x 3950x that don't reach to 1800Mhz infinity fabric. The system just simply won't boot at those settings.
So I was thinking if there would be any performance benefit running IF at eg: 1500Mhz instead of 1800Mhz, when RAM speeds reach 4500Mhz?