RAM frequency for Omen 870-244

[dwsmith42]

Omen came installed with DDR4 2666, PC4-21300 memory modules. According to online information for the i7-7700 processor which came installed, memory speed is limited to 2440. I replaced the original two 8G modules of HP memory with two 16G modules of Corsair Vengence LPX. Online information indicates the board, a Thimphu-K supports 16G modules and up to 64G, although HP has not "tested" more than 32G and does not "recommend" upgrading to 64G. 

I also found that one page on the HP support WEB site stipulated only DDR4 2133 memory, PC4-17000, while the actual memory in the machine was DDR4 2666 PC4-21300. All very confusing. So, there is a documented difference between what the board supports, what the upgrade path stipulates and what was installed in the machine. What was in the machine is closer to what the board actually supports.

The 16G kit I installed is working fine. However, neither that kit or the original 8G kit from HP show frequencies over around 1083 or so, nowhere near 2133, 2440 or 2666. So, I'm puzzled why the memory does not appear to be running at anywhere near the max speed or frequency.

Perhaps I'm misunderstanding the ratings?

[Paul_Tikkanen]

HI:

It is not clear according to the processor specs from Intel exactly how fast the processor will run the memory at  is it 2133 MHz or 2400 MHz?

https://ark.intel.com/content/www/us/en/ark/products/97128/intel-core-i7-7700-processor-8m-cache-up-...

Anyway, from the report you have that shows a 1083 MHz speed, you have to double that amount to get the memory speed, since it is running in dual data rate (DDR) mode.

Seems that the memory is running at 2133 Mhz.

When I run a similar report on my PC's memory (PC3L-1600), it shows 798.2 MHz.

Since the memory is running in DDR mode that is 798.2 x 2 = 1596.4 MHz

As far as to why HP installed 2666 MHz memory in your PC?

Probably because that is what they have on hand.

It just downclocks to the fastest speed the processor's FSB can run the memory at.

[dwsmithjr]

Thanks for the information.

Based on the information I found on the processor, it seemed that 2400 was the max speed. So, I'm not expecting 2666. The point that you need to double it is helpful. I wasn't aware of that. So, it's a max of 2133 or 2400 for both channels together.

Thanks again.

[Paul_Tikkanen]

You're very welcome.

That is correct.