Question PC doesn't boot with XMP enabled ?

[Dschorr]

Hello all,

i have run into a problem with my memory speed in the last couple of months.

PC parts:
AMD Ryzen 7 5800X 8x 3.80GHz So.AM4 WOF
32GB Corsair Vengeance LPX DDR4-3600MHz (4x8GB) DIMM 288-PIN PC4-28800
Gigabyte B550 Aorus Elite AX V2 So.AM4 ATX Retail

With XMP Profile 1 enabled, PC doesn´t boot or gets black screen/frozen or gets looped in auto repairing.
Once i set the values manually
16-19-19-36 with 1.35 volts i can get instead of 2133 to 2400 everything above wont boot or boots but with 2133mhz.

I contacted "official" support who suggested that my 850W PSU isnt enough so i even upgraded to 1000W (is a nice upgrade for the future anyway)

I would really appreciate any help!
Thanks in advance.

 

[rgd1101]

exact model of the ram?
latest motherboard bios?

 

[General_Cool]

Is your BIOS showing the ram speed in MHz or MT/s?

 

[Dschorr]

Is your BIOS showing the ram speed in MHz or MT/s?

The current ram speed is shown in MHz

 

[Dschorr]

exact model of the ram?
latest motherboard bios?

RAM: CMK32GX4M4D3600C16
Bios is upto date version, F17h (12.25.2023)

 

[General_Cool]

The current ram speed is shown in MHz

You’re trying to overclock your RAM right now to almost 4800 MT/s, when its only rated for 3600 MT/s. RAM manufacturers advertise their MT/s as MHz since its easier for consumers to understand. Since RAM is double data rate (hence DDR) that means MHz x 2 = MT/s. Therefore, when your BIOS shows 1800 MHz, its really saying its running at 3600 MT/s, AKA as advertised. No wonder its struggling at higher than that…its not supposed to be that fast.

 

[Dschorr]

The ram is advertised as 3600 MHz: https://www.corsair.com/us/en/p/mem...ory-kit-black-cmk32gx4m4d3600c16#tab-overview

I dont mind overclocking my ram´s to 3600 to my knowledge you are supposed to get them to 3600MHz, but for me even 3200 would be fine, just not the slow 2133MHz

 

[General_Cool]

The ram is advertised as 3600 MHz: https://www.corsair.com/us/en/p/mem...ory-kit-black-cmk32gx4m4d3600c16#tab-overview

I dont mind overclocking my ram´s to 3600 to my knowledge you are supposed to get them to 3600MHz, but for me even 3200 would be fine, just not the slow 2133MHz

I don’t think you understood what I meant. Megahertz is not megatransfers per second, megatransfers per second is megahertz times two, because RAM is double data rate. When your BIOS shows 1800 MHz, your ram is running at 3600 MT/s. RAM is not advertised in MT/s though, it is advertised in MHz for consumers to understand it easier, as MT/s is not as widely used as the term MHz. Sadly it leads to situations like this where the consumer gets confused. I can assure you that by setting your RAM to 1800 MHz in the BIOS, it will be running at the speeds advertised by the manufacturer. You may choose to overclock it to say 2133 MHz, but that would mean it would be running at 4266 MT/s. If that works, then awesome, if not, then oh well the RAM wasn’t advertised for that speed anyways.

If you are still confused by what I wrote, then by setting your RAM to 1800 MHz in the BIOS, it will be running at 3600 MHz, because the motherboard takes the number you input and doubles it, so it takes your 1800 and multiplies it by 2, giving you your 3600 MHz RAM as advertised. (This way of explaining it is easier to understand due to the confusion from RAM manufacturers but technically speaking wrong)

 

[Dschorr]

Well

I don’t think you understood what I meant. Megahertz is not megatransfers per second, megatransfers per second is megahertz times two, because RAM is double data rate. When your BIOS shows 1800 MHz, your ram is running at 3600 MT/s. RAM is not advertised in MT/s though, it is advertised in MHz for consumers to understand it easier, as MT/s is not as widely used as the term MHz. Sadly it leads to situations like this where the consumer gets confused. I can assure you that by setting your RAM to 1800 MHz in the BIOS, it will be running at the speeds advertised by the manufacturer. You may choose to overclock it to say 2133 MHz, but that would mean it would be running at 4266 MT/s. If that works, then awesome, if not, then oh well the RAM wasn’t advertised for that speed anyways.

If you are still confused by what I wrote, then by setting your RAM to 1800 MHz in the BIOS, it will be running at 3600 MHz, because the motherboard takes the number you input and doubles it, so it takes your 1800 and multiplies it by 2, giving you your 3600 MHz RAM as advertised. (This way of explaining it is easier to understand due to the confusion from RAM manufacturers but technically speaking wrong)

I think i understood, but if we use your measures than all i can get out of my rams is 1200, see picture below

https://ibb.co/BcrXbsz

 

[General_Cool]

Well

I think i understood, but if we use your measures than all i can get out of my rams is 1200 see picture below

https://ibb.co/BcrXbsz

I see the issue now...your RAM is supposed to be running at 1800MHz, but you can't get it above 1200MHz.

Is this RAM still in warranty? Have you tried testing each stick individually in the board with the XMP profile? Have you tried testing other RAM? It comes down to either your motherboard or your RAM.

 

[Dschorr]

I see the issue now...your RAM is supposed to be running at 1800MHz, but you can't get it above 1200MHz.

Is this RAM still in warranty? Have you tried testing each stick individually in the board with the XMP profile? Have you tried testing other RAM? It comes down to either your motherboard or your RAM.

So i tested all the RAM´s individually, one-by-one, and it turns out that once i enable XMP, 1 of the 4 sticks won't go with it.

That must be the problem. I will try and send them back.

General question:
Do i go 4x8 like know or is the 2x16 better for performance, stability etc.?

 

[General_Cool]

So i tested all the RAM´s individually, 1by1 and it turnes out that once i enable XMP 1 of the 4 wont go with it.

That must be the problem. I will try and send them back.

General question:
Do i go 4x8 like know or is the 2x16 better for performance, stability etc.?

Glad to hear you determined it wasn’t a software issue.

DDR5 systems work better with two sticks, but for DDR4 it doesn’t matter. You can just continue with 4x8 sticks.

 

[PiersPlowman]

Zen 3 IMC specs:

Max Memory Speed
2x1R
DDR4-3200
2x2R
DDR4-3200
4x1R
DDR4-2933
4x2R
DDR4-2667