Question i3-9100F, maximum RAM 2400

A_Goat

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So apparently the i3-9100F locks RAM speed to 2400Mhz... what in the heck? Never seen that before.
Is there anyway around this with a B365 motherboard? I know it would be an infinitely tiny difference, but the MOBO supports up to 2666... anyway I can force it?
 

MadsModsat

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I had an i3 9100F running with 32GB Kingston HyperX Fury 2666MHz RAM (4x8 GB, actually two different kits purchased seperately, crazyness :p ) running on my current motherboard, when my 9900K had to be RMA'ed a while back. I'll attach a screendump.

i3 9100F - 2666MHz - HWInfo + CPU-z
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It was also possible with my current 3333MHz RAM and the i3 9100F

All I had to do for 3333MHz was to enable XMP. The Kingston RAM only runs 2666MHz, that's the only frequency of the RAM (as you can tell by CPU-z in my screenshot), so the only thing enabling XMP did for them, was absolutely nothing, I don't even know why they have an XMP profile.

But no fiddling with settings, no special feautres or mods, it ran with default settings and nothing more.

So it is definately possible on a Z-series chipset, I don't know about a B365 chipset, as I have no experience with that. Someone else will know a lot better than I do. But it might be limitations on yur specific motherboard model, the chipset specifically, which is the problem.
 
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The B365 chipset does not support ram overclocking.
https://en.wikipedia.org/wiki/LGA_1151

Ram faster than 2400 is technically overclocked ram.
This is usually done via a xmp setting.

It is a moot point since there is very little difference in actual app performance or fps with 2400 vs 2666 ram and even higher speeds. That applies to using a discrete graphics card as you will be doing with a 9100f.

If your motherboard supports 2666 speed, and you have 2666 ram, you could try to set 2666 via xmp.
If you buy 2666 ram to try, it will at least run at default speeds.
If you want the best ram performance, look for lower cas numbers.
 

A_Goat

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The motherboard is B365M-ITX/ac from ASROCK, latest BIOS installed. I know the performance gain will be minor, I said that in the original post :D But the motherboard supports up to 2666, so if I can get my RAM to run at that speed I'd do it. But on the intel ark website for the 9100F, it states "memory types: 2400" https://ark.intel.com/content/www/us/en/ark/products/190886/intel-core-i3-9100f-processor-6m-cache-up-to-4-20-ghz.html

This is the link ASrock referred me to when I asked why I couldn't enable the 2666Mhz speed in the BIOS. I did not know that modern CPU's would limit memory speed below their clock rate, let alone that far below. I already tried enabling the XMP profile, manually settings the speed to 2666, and manually setting the speed to above 2666.
 

MadsModsat

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If the B365 chipset doesn't allow RAM overclock, you can't run memory at the 2666MHz the chipset / motherboard actually supports, unless you also have a CPU that supports 2666Mhz RAM natively as well.

The i3 9100F's integrated memory controller (IMC) supports 2400MHz maximum, while the rest of the 9-series, for example the 9400K, 9600K, 9700K, and 9900K has an integrated memory controller that supports a maximum frequency of 2666MHz.

So it makes sense that your motherboard support up to 2666MHz RAM, since it is designed to support Intel 9th Gen, but with that chipset, your CPU's IMC also needs to support 2666MHz RAM, since it can't overclock.
Setting an XMP profile doesn't just speed up your RAM clock, it affects the IMC as well, and you need a Z-series chipset to alter the IMC performance in order to support RAM frequencies above spec.

That is why AsRock referred you to that page, it tells you that the 9100F has a lower memory frequency support than the other 9th Gen CPUs (most of them at least, I haven't managed to look all of them up yet, so there might be other exceptions).
 
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