How fast will this ram clock using XMP on this motherboard?

[Andrewxe]

I'm Planning to buy https://www.asrock.com/mb/Intel/B760M Pro RSD4/index.asp#Specification with https://www.tpstech.in/products/g-skill-trident-z-ddr4-16gb-4133mhz-desktop-memory .

Since the ram is at 4133MHz, when using XMP at what speed will it run since exactly 4133 is not mentioned don't he specs of the motherboard.

• Memory
  - Dual Channel DDR4 Memory Technology
  - 4 x DDR4 DIMM Slots
  - Supports DDR4 non-ECC, un-buffered memory up to 5333+(OC)*
  - Supports ECC UDIMM memory modules (operate in non-ECC mode)
  - Max. capacity of system memory: 128GB
  - Supports Intel^® Extreme Memory Profile (XMP) 2.0
   

  *1DPC 1R Up to 5333+ MHz (OC), 3200 MHz Natively.
  1DPC 2R Up to 4400+ MHz (OC), 3200 MHz Natively.
  2DPC 1R Up to 4266+ MHz (OC), 3200 MHz Natively.
  2DPC 2R Up to 4000+ MHz (OC), 3200 MHz Natively.

   

   

[Agall]

15 minutes ago, Andrewxe said:

I'm Planning to buy https://www.asrock.com/mb/Intel/B760M Pro RSD4/index.asp#Specification with https://www.tpstech.in/products/g-skill-trident-z-ddr4-16gb-4133mhz-desktop-memory .

Since the ram is at 4133MHz, when using XMP at what speed will it run since exactly 4133 is not mentioned don't he specs of the motherboard.

• Memory
  - Dual Channel DDR4 Memory Technology
  - 4 x DDR4 DIMM Slots
  - Supports DDR4 non-ECC, un-buffered memory up to 5333+(OC)*
  - Supports ECC UDIMM memory modules (operate in non-ECC mode)
  - Max. capacity of system memory: 128GB
  - Supports Intel^® Extreme Memory Profile (XMP) 2.0
   

  *1DPC 1R Up to 5333+ MHz (OC), 3200 MHz Natively.
  1DPC 2R Up to 4400+ MHz (OC), 3200 MHz Natively.
  2DPC 1R Up to 4266+ MHz (OC), 3200 MHz Natively.
  2DPC 2R Up to 4000+ MHz (OC), 3200 MHz Natively.

   

   

Memory controllers are in the uncore or I/O die (Intel or AMD respectively), so a motherboard's 'support' for a certain speed doesn't indicate the CPU itself will handle that memory speed. They used to be on the motherboard, so outside of the RAM QVL, its somewhat meaningless.

 

I haven't seen much data on high end DDR4 speeds on B760, but the CPU in question also supports DDR5 if that's an option, instead of going high end DDR4.

 

To answer your question, 4133MHz on the RAM kit would indicate that each DIMM is running at 2066MHz, because the speed advertised for Dual Data Rate memory is usually 2x what it actually runs at. This is because DDR memory transfers data twice per cycle, so a lot of companies just list the 'effective speed' just like how graphics cards with GDDR5x/GDDR6/GDDR6x have ridiculous +10GHz 'effective' memory speeds.

[RONOTHAN##]

It's complicated. 

 

That kit is going to be single rank, and if you're only running two sticks it would fall under the *1DPC 1R subcategory, so assuming you've got a -K SKU CPU it can run at over 5GHz. Unfortunately, advertised RAM speeds per board are generally pretty meaningless as there's so many other factors in play and motherboard manufacturers like to over-exaggerate the capabilities of their boards.

 

The big things to know are that the Intel memory controller has two main modes for DDR4, Gear 1 and Gear 2, and that the non-K CPUs have a significantly weaker memory controller due to them having locked internal voltage rails. Gear 1 vs. Gear 2 is a little complicated, but the short version is Gear 1 has a lower max clock speed but better latency figures, while Gear 2 can do much higher clock speeds with a latency penalty. That latency penalty can sometimes be overcome if you run memory at insane clock speeds (5000+), but it's rare and you're usually better off just sticking to Gear 1. Taking that into account, you need to look at what speeds will actually run in each mode. On the -K SKUs, the range is usually between 3800 and 4200 as the max in Gear 1 (there are a couple chips that can go above this though), and ~5000 in Gear 2. On the non-K SKUs, the range is closer to 3466-3866 in Gear 1 and ~4400 in Gear 2. 

 

As for what would happen if you just enabled XMP, it would run at DDR4 4133 CL19 as that is a memory ratio on LGA 1700. It's just that you will be in Gear 2 and therefore get worse performance than if you had stuck with a cheaper kit at 3600 CL14, or just manually dialing in 3600 CL14 anyway. 

[Somerandomtechyboi]

Non k cpus have locked vccsa so youll need gear 2 to hit 3600+

 

B660m pg riptide is a better board choice since you can oc non k and k cpus via bclk, there is a b760m version but its ddr5

 

Thats likely just unbinned micron rev e or hynix djrs, cheap shit you can buy off cheap bare pcbs like hma81/82gu6djr8n and manual oc to 4600+

 

 

Its 2x8 and 4133 so itll be single rank (1r) and since theres only 2 sticks its 1dpc, falls into the first spec which is upto 5333 ddr4, so basically anything up to 5333 will theoretically work which includes 4133

 

beware that >4000 xmps are generally quite unreliable and also just stupid pricey, for that 4133 kit problably some unbinned hynix djrs or micron rev e since its just generic gskills, same shit you get in 2666 oem jedec hynix/micron sticks (the aformentioned hma81/82gu6djr8n). id reccomend a 4000/4133 klevv kit instead as klevv is just hynixes consumer devision and these are problably binned hynix djrs not cheap shit you can buy for 10$ thatll only top out at like 4800-5200, but if you arent trying to reach stratospheric speeds those aformentioned bare pcbs would be a good choice

 

Spoiler

 

and yes those speeds are attainable though quite annoying to hit, trying to stabilize those speeds is a whole other thing though

 

If performance is what you seek then there is no other way than manual tuning, money wont buy you fast rams unless you tune em first, even those ridicolous 5333 bin tridentz royals are no exception

[Andrewxe]

I am trying to pair it with 12th Gen Intel Core i5-12400F

My other option is G.Skill F4-3600C18S-8GVK Desktop Ram Ripjaws V Series 8GB (8GBx2) DDR4 3600MHz

Trident will be bought used so they are basically the same price, if I picked up either one, will enabling XMP will be just fine?