'safe' DDR5 voltages? [AM5]

[Clutch_Head]

Currently on a 9950x via MSI x870E Tomahawk, with CORSAIR Vengeance DDR5 96GB (2x48GB) DDR5 6000MHz CL30 (sku 'CMK96GX5M2B6000Z30')
Running the AMD Expo profile... they are at 1.4V. Is this high for the memory controller/IO die on the CPU?
Should i be worried? Should i lower the voltage and test?

Thanks

 

[freeagent]

Its a lot of ram, gonna take some voltage..

 

[Woomack]

96GB 6400 CL32 kits are 1.40V XMP/EXPO. All low-latency kits are Hynix A/M, so they all have +/- the same voltage requirements (+/- 0.05V).
It depends more on temperatures, but this is tricky as sensors are usually not showing memory chips temp, but PCB/SPD. You can see even +/- 10°C between some memory kits at the same voltages, but different brands (still the same memory IC, PMIC and other stuff).
Up to 75°C under extended load should still be fine, but if you set lower timings, it will show instability faster. I have never had any problems up to 1.55V on AMD and Intel, but I see no point in pushing it on AMD as it gives close to 0% performance gain out of synthetic benchmarks.
You can assume that up to 1.45V is guaranteed to be safe, as many kits use this voltage in XMP/EXPO. Some kits used to have 1.50V XMP, so this should be safe, too, as no manufacturer would risk a high RMA rate.

On AMD, all other voltages are locked at safe values, or the motherboard will mark high values red, so you know it's not safe/guaranteed. Some motherboards will have 1.435V as max VDD/VDDQ as it's max JEDEC value.

 

[deathstar13]

Good info to learn Woomack!
From what ive seen so far with my rig and experience is OC'ing DDR5 doesn't have much headroom.
My ram is TCreate 6000Mhz CL30 @1.35v My best Ocing was to just bump it up too 6200Mhz CL30 @1.35v

Also i added copper heatsinks and a 60mm fan over my ram. These i used thermal ta0pe to afix them to the aluminum factory heat spreaders. So my ram is set for higher voltages.

Amazon.com

Im not going to spend alot of time on this 32MB kit as im going too 2x48 GB / 96GB like you and ive heard they actually oc well.

 

[Woomack]

Your problem is not the RAM but the chipset/memory controller. AMD CPUs generally don't like anything at an asynchronous IMC ratio, so the optimal is 6000-6400 1:1 at, let's say, tight timings. Most of the popular memory kits can go up to 7600-8400, but AMD simply doesn't like it.

 

[deathstar13]

Thats very true, Also is why AM% doesn't much like 128MB of DDR5.
Personally id rather have 6000Mhz and tight timings over high Mhz and loose timings.
I thought the memory controller was on the cpu, if so can you overvolt it? Just where is the controller located?

here is what im switching too.7000Mhz would be great!

Amazon.com

Id suggest if your able to to lower and test in .01v increments. But i wouldnt be afraid of 1.4v

 

[67Elco]

I used this with the 9900X and it liked it... https://www.amazon.com/dp/B0DTNR3SQ8?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

 

[Woomack]

I used this with the 9900X and it liked it... https://www.amazon.com/dp/B0DTNR3SQ8?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

It doesn't work at a 1:1 ratio, so it's slower than 6000-6400. Even 8000 is generally slower, or in the best case equal. The same as on Intel 8800 Gear 2 is faster than 10000 Gear 4.

 

[deathstar13]

I used this with the 9900X and it liked it... https://www.amazon.com/dp/B0DTNR3SQ8?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

Thats some fast ram and nice and tight timing for that speed, Just wish they had a 96GB or 128GB set of sticks.
Those are 1.4v also so if they were mine 1.45v wouldnt scare me.
Looks like i need to try and overvolt mine also. Mine runs at 1.35v

What timings did you have on your sticks?

Post magically merged: Mar 25, 2025

It doesn't work at a 1:1 ratio, so it's slower than 6000-6400. Even 8000 is generally slower, or in the best case equal. The same as on Intel 8800 Gear 2 is faster than 10000 Gear 4.

At what speed do you hit to go out of 1:1 on AM5?

 

[EarthDog]

At what speed do you hit to go out of 1:1 on AM5?

I think we covered this in your original build thread, but it varies by motherboard but could be 6200MHz+ depending on multiple variables.





Also, for everyone, this thread is for Clutch and has to do with safe voltages. Let's keep on subject.

 

[67Elco]

It doesn't work at a 1:1 ratio, so it's slower than 6000-6400. Even 8000 is generally slower, or in the best case equal. The same as on Intel 8800 Gear 2 is faster than 10000 Gear 4.

I'm not into the memory overclocking much and I simply chose those because they looked great in the Evolv 2 build.

 

[freeagent]

Quick what's the safe word?!

I have a hard time past 6200 myself. Not sure if its me, my ram, my board, or my CPU. I could play around at 8000 but stable past 6200 is tough for me. Probably because I don't really know what I am doing yet.. just enjoying the speed as is..

 

[deathstar13]

I personally feel you can run 1.45v 24/7 and upto 1.5v for bench runs.
Ive gotten my 6000Mhz CL30 upto 6600Mhz at 1.4v but never stable,Not even stable at 6400 either.
But i can easily run 6200Mhz Cl30 @1.35v stable.
I feel the memory controller has issues past 6200Mhz from my research and own trials.
My new ram im getting which will be here in a few days is 6400Mhz CL32 and if need be ill drop it down too 6200Mhz @1.35v
Ive not seen any 2:1 issues yet

 

[Woomack]

One of the kits that I have is after review, and I removed the heatsinks damaging thermal pads. I didn't care to spend money on new thermal pads, so it runs without heatsinks, and I've never had problems at 6400 1.45V in extended runs.